BMT AbstractsInternational Maritime TechnologyVolume 70 Number 6 June 2015

Abstract Numbers 2015061251 – 2015061500

ISSN 2051-7793

BMT ABSTRACTS

Volume 70, Number 6, June 2015 Abstracts 2015061251-2015061500

Compiled and Edited by: Gillian Smith Information Services BMT Group Limited Goodrich House 1 Waldegrave Road Teddington Middlesex TW11 8LZ U.K. Tel: 07909991180 Email: gilliansmith@bmtmail.com

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Abstracts 2015061251-2015061500 Volume 70 – No 6 – June 2015

CONTENTS

Page No.

1. DESIGN AND CONSTRUCTION

1.1 Ship/structure description 462 1.2 Design 462 1.3 Shipbuilding technology/constructional techniques 473

2. OPERATION

2.1 Power sources and fuels 474 2.2 Equipment and installations 475 2.3 Maintenance, repair and conversion 477 2.4 Cargoes and cargo handling 478 2.5 Ports and waterways 478 2.6 Coastal/offshore engineering and marine renewable energy 479 2.7 Safety at sea 486 2.8 Environmental protection 490 2.9 General operation 491

3. FLUID MECHANICS

3.1 General hydrodynamics, hydraulics and oceanography 497 3.2 Resistance and propulsive performance 498 3.3 Motion, seakeeping and manoeuvring 509 3.4 Fluid structure interaction 521 3.5 Aerodynamics and wind engineering 532

4. STRUCTURES AND MATERIALS

4.1 Structural response 532 4.2 Properties of materials 546 4.3 Corrosion and fouling 550

5. NAVAL VESSELS AND DEFENCE TECHNOLOGY 552 6. MISCELLANEOUS 553

AUTHOR INDEX A-1 SHIP AND STRUCTURE INDEX S-1 KEYWORD INDEX K-1

1.1 SHIP/STRUCTURE DESCRIPTION

2015061251

Super efficient MR delivered. Tanker Operator, v 14 n 4, March 2015, p 22 [4 p, 4 fig] http://www.tankeroperator.com/AllMagazine.aspx No author given English

This article describes STENA IMPRESSION an IMOIIMAX 50,000 DWT MR chemical tanker owned by Stena Bulk and Indonesian's Golden Agri Resources (GAR). STENA IMPRESSION, the first of a ten vessel order is under construction at Guangzhou Shipyard, China. The IMOIIMAX tankers have been designed to transport both vegetable oils and chemicals, as well as clean and dirty petroleum products. The tanker has 18 tanks of the same size, each with a capacity of 3,000 m3, which allows for increased cargo flexibility. Some of the technical solutions fitted on board that will result in more energy efficient consumption and greater logistic flexibility, include: increased boiler efficiency, propeller energy loss recovery, and accommodation and bridge aerodynamics, that result in 10-20% lower fuel consumption at service speed compared with other vessels of the same size.

Chemical tankers Vessel descriptions

2015061252

Iceland gives hull design the OK. Ship & Boat International, March/April 2015, p 24 [3 p, 2 fig] http://www.rina.org.uk/sbi.html No author given English

After years of research and testing, Icelandic boat builder Rafnar Shipyard has concluded sea trials of the first two craft to feature its new and unique OK Hull design: the 10m RIB LEIFTUR and the 12m fast open boat THORBJÖRG. The unique ‘displacement’ shape of these hulls implies that they always drive ‘through’ the water, not breaking above the surface of the water nor reaching a planing aspect. The sea trials demonstrated that, even at 40 knots in choppy

seas, one experiences little slamming effect and amazing control and stability during full-lock at full speed.

Boats Hull form Rigid inflatable craft Small craft Vessel descriptions

1.2 DESIGN

2015061253

A new design of container carriers for maximizing cargo capacity. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Im, H-I., Choi, B-k., Et al English

This paper introduces the SkyBenchTM container carrier which Hyundai Heavy Industries Co. is developing. The SkyBenchTM container carrier which overcomes the limitations of space utilization using mobile concept at superstructure provides the owners with maximized utilization of space through loading more cargo compared with the similar size of conventional design.

Cargo capacity Containerships Ship design

2015061254

Considerations in a holistic investigation of the feasibility and potential advantages of gas turbine based propulsion for future container ships. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Fitzgerald, M., Andrews, D., Et al English

This paper sets out a framework within which information can be passed between the preliminary design stages of both the ship and machinery to inform and progress the designs to select the best overall design. Traditional methods of ship machinery

ABSTRACTS 462

selection are discussed and a new approach of concurrent development of both ship and prime mover is outlined.

Containerships Gas turbines Power plant selection Ship design

2015061255

Development of an ‘automated’ CAD model generation of globally optimised container ship design. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Chauhan, A., Chauhan, U. English

Preliminary design of a ship relies on generation of parameters through empirical estimations. However, these may vary marginally or significantly as compared to those in real-time. In the method presented, the design cycle starts with input of ship-owner's requirements - this starts an ‘automated’ process for preliminary estimation, CAD model generation using NURBS surface, iterative optimisation and decision making based on multi-variable parameters. A database of existent models speeds up optimisation through interpolation techniques as an initial tool. CAD model generation using NURBS surface helps in better estimation of actual parameters in ship design which improves empirical estimations. This process reduces significant errors and is critical in preliminary ship design. The given preliminary container ship design module uses a global optimisation model utilizing different constrained multi-criteria crucial for ship design including container space requirements, freight rate charges, etc. In the final stage, geometric modelling is done to compartmentalize interior spaces for container accommodation. Also, the model allows verification of regulation constraints for stability and global longitudinal strength analysis.

Computer-aided ship design Containerships

2015061256

Holistic applications in containership design. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Nikolopoulos, L., Papanikolaou, A., Et al English

High fuel prices, low freight rates and environmental concerns have influenced the design and operational characteristics of all types of ships. In recent years particularly container ship designs were considerably changed towards a new generation of ECO-ship designs. These designs correspond to ships with lower emissions, lower operational costs and increased competitiveness compared to traditional tonnage. This paper presents a holistic, multi-objective optimisation procedure for the design of such containerships. It encompasses the development of parametric models for the optimisation of medium size (between 3,500 and 4,000 TEU) vessels with emphasis on Intra-Asian trade. Fully parametric geometric modelling techniques of simulation driven design are employed in the frame of the CAD/CAE environment of FRIENDSHIP-Framework, combined with sophisticated assessment tools for the evaluation of critical ship design attributes, such as ship weight, stability, resistance and powering, for common operational conditions. The developed multi-criteria and multi-staged optimisation approach enables the effective exploration of an extended design space (with the utilization of genetic algorithms-NSGA II) targeting the minimization of the required freight rate, as well as of the Energy Efficiency Index and the minimization of ballast water carriage for the common operational conditions (in some cases it can be considered zero). Further emphasis is put on enhancing port efficiency to reduce time in port and consequently allow the reduction of transit speed between ports, as defined in previous research work and simulations.

Containerships Efficiency Optimisation Ship design

463 ABSTRACTS

2015061257

Influence of hull flexibility and hull girder vibrations in the design of modern ultra large container ships. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Chatzitolios, K. English

The considerable increase in the size of container ships affects their hull girder flexibility making Ultra Large Container Ships (ULCS) inherently more flexible. The flexible hull girder can become susceptible to vibrations induced randomly by the sea and periodic vibrations induced by mechanical equipment. Random hull girder vibrations from whipping (slamming) contribute to increased fatigue damage and extreme loading while hull girder vibrations induced by springing influence only fatigue life. The line shafting diameter of ULCS is commonly about 1m and even more for accommodating the high output power. Consequently, the line shafting is very stiff and its static and dynamic interaction with the flexible hull must be carefully studied using dedicated methodology for defining the optimum alignment conditions. In addition, the decrease in natural frequencies of the more flexible hull results in a higher risk of resonant response of the hull girder vibration modes to the excitation frequencies of the main engine and the propeller. The resulting vibrations can lead to damages in the ship's structure, influence the behaviour of the engine and other equipment and also impact negatively the comfort of the crew. The advanced methodologies that Bureau Veritas and Tecnitas have developed and are applying to mitigate the risks emanating from the static and dynamic interaction between propulsion plant and hull of ultra large container ships are presented. The impact of whipping and springing on the extreme loads and the fatigue life is also shown together with possible design solutions.

Containerships Flexibility Hull vibration Ship design

2015061258

The ultimate Jones Act dry cargo carriers – an innovative LNG fuelled container ro-ro vessel. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Nichita, C., Nabergoj, T., Sonechko, D. English

The coming into force of the newly established ECA on the Eastern and Western board of the USA combined with the low price of LNG has raised the interest of traditionally "ATB minded" owners to invest in ship shaped vessels to operate them on the protected Jones Act trade routes. In this paper, Wärtsilä Ship Design highlights the ship's layout and the design challenges of the innovative solution for a general cargo vessel suitable for carriage of containers in cellular cargo holds and on-deck/hatches, and vehicles in the RO-RO superstructure located aft. The vessel, tailored for a US customer, featuring 219m (LOA) x 32.24m (B) x 1Sm (D) x 10m (Tsc) is powered by an SS70ME-CS.2·GI. TII two stoke high pressure main engine with 3 9L2S132DF low pressure auxiliary engines from MAN Diesel & Turbo and a fuel gas supply system from TGE Marine Gas Engineering GmbH, equipped with abt. 2,300m3 LNG capacity in 3 tanks, to provide a service speed in excess of 21kts for more than 6,000nm endurance. CFD optimised with state-of-art tools and model tested at prime model test facilities, with the basic design already started, designed to carry a wide mix of standard and high cube 20ft and 40ft (ISO standard), and 45ft/53ft wide body and high cube containers (US standard)- 2500TEU equivalent containers, and RO·RO cargo up to 2.2t private US size vehicles as well as up to 15t trucks and others vehicles, will serve one of the Jones Act trades, a highly demanding emission controlled and competitive area.

Containerships Liquefied natural gas Ro-ro ships Ship design

ABSTRACTS 464

2015061259

Traditions broken in modern container ship design. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Hooijmans, P.M., Meij, K.H van, Greening, D. English

Modern container ship designs are being balanced for minimum fuel consumption and maximum loadability. The 10000 SAVER developed by the Canadian Owner Seaspan Ship Management Limited, the Marine Design and Research Institute of China (MARIC) and the Maritime Research Institute Netherlands (MARIN) is one of these pioneers. This design breaks with the tradition of focusing on a design point, design draught and trail speed, and instead optimises the ship for the intended/expected operational profile. This paper addresses the multi-objective design aspects and the challenges experienced in the ship design process from an owner, yard and hydrodynamic point of view. For the design of the SAVER 10000, the operational profile provided by Seaspan was taken into account to develop a hydrodynamic fuel efficient design, whilst on the other hand allowing for the maximization of the loadability of the expected cargo profile. This has allowed the development of a design that balances the fuel consumption with the load carrying capacity across the operational profile of the ship. This provides a ship with superior performance as compared to a traditional design which often operated off of its design condition. The importance of the operational profile is further highlighted by the fact that the requirements of two different charterers resulted in two different designs. Both designs utilized the same hull form but had different amounts of installed power driving different high efficiency propellers. The design of the aft hull and the propellers was constrained by the need to control the propeller induced pressure pulses and related vibration issues in the construction of the vessel. From a seakeeping point of view, the longitudinal strength with respect to springing and whipping is addressed as well as the added resistance due to waves.

Containerships Ship design

2015061260

Gameplay approach to virtual design of general arrangement and user testing. International Conference on the Education & Professional Development of Engineers in the Marine Industry, 15-16 April 2014; Busan, Korea. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Ahola, M., Magica, R., Et al English

This paper presents a new approach to general arrangement design using a novel virtual reality tool developed in Aalto University. The software platform combines elements from 3D modelling, virtual reality, user testing, and gameplay. The tool enhances the understanding of the consequences of design decisions by providing the designer the ability to observe and conceive ship interiors in real-world scale instead of the limited scale available through a traditional computer screen or a projector. Secondly, the software enables new way of straightforward user testing, in which the designer can actively communicate with the user exploring the virtual ship model. In addition to observing users actions in real time, user behaviour can be recorded systematically for later analysis and repeatability. The tool is realized as a portable system containing an Oculus Rift headset, a console game controller and custom-made game software enabling importing and manipulating of different CAD formats. The tool is progressively being developed further, with aim to support educational and decision-making processes.

Computer-aided ship design General arrangements Virtual reality

2015061261

Development of non-ballast-water tankers and bulkers with electric podded propulsors. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper I-1, p 17 [11 p, 4 ref, 5 tab, 19 fig] http://www.int-nam.yildiz.edu.tr/2014/ Ikeda, Y. English

In this paper, a new non-ballast-water tanker and bulk carrier developed in a research project with Osaka Prefecture University and nine shipbuilding-related companies in Japan is introduced. The ship can delete

465 ABSTRACTS

all ballast water by keeping the propellers in deep condition by moving electric pod propulsors down in light weight condition. To reduce the viscous frictional and pressure resistances in full load condition, the ship has round body sections in the parallel part to minimize the wetted surface and a streamlined buttock flow stern body to reduce the viscous pressure resistance.

Ballast water Bulk carriers Propulsive efficiency Ship design Tankers

2015061262

Dynamic positioning in early design stages. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper II-2, p 91 [10 p, 11 ref, 3 tab, 13 fig] http://www.int-nam.yildiz.edu.tr/2014/ Lübcke, A., Krüger, S. English

Dynamic positioning (DP) is the capability of a vessel to automatically keep its positon in open water by counteracting the environmental forces caused by wind, waves and current. Such systems are of growing importance. Both the accurate prediction of the limiting environmental conditions and the design of a DP-System for specified limits save costs due to the fact that the operating time of the vessel can be increased, anchoring becomes unnecessary and the use of expensive tugs is avoided. Typical applications of DP are offshore crane and jacking operations as well as virtual anchoring for passenger ships. To make a precise statement about the DP capability, a calculation method has been developed by the authors. The paper shows how the calculation of the DP capability is carried out by taking into consideration the interaction effects between the propulsion system and the hull as well as the environmental forces. To determine the interaction effects model tests were performed. The results are also presented in this paper and allow a more precise statement about these effects.

Dynamic positioning Model tests Ship design

2015061263

Derrick structure design and finite element analysis of COPE-16 jack-up. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4542-4. Volume 4A: Structures, Safety and Reliability, Paper No. OMAE2014-23099 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911595 Ji, Z., Gang, C., Et al English

The drilling derrick, acting as one of the most important structures in a jack-up rig, is designed to accommodate drilling machines like top drive, utility winches and so on. According to the requirement of API Spec. 4F, the accuracy of the standard design ratings of each structure shall be tested by proof loading or a computer model such as Finite Element Analysis. Therefore, this paper utilizes Finite Element Analysis software, ANSYS, to verify the design of derrick structure for CPOE-16 (No. 16 jack-up rig for China National Petroleum Offshore Engineering) jack-up based on API 4F [1], AISC Allowable Stress Design and ABS MODU rules. The permanent loads, live loads (variable functional loads), environmental loads (mainly wind loads) and dynamic loads will be included in the total derrick structure strength calculation with the purpose of verifying the security and reliability in all required conditions by rules and regulations. Furthermore, on the basis of analytical result, the authors focused on the adverse beams provide an optimisation solution by improving the section of beams for reducing the distortion, and ultimately deal with the distorted problem.

Derricks Finite element method Jackup platforms Platform design

ABSTRACTS 466

2015061264

Study on bow shape optimisation of ultra large block coefficient ship and CFD simulations of initial and optimised hull forms. Journal of the Japan Society of Naval Architects and Ocean Engineers, v 20 2014, p 1 [11 p, 15 ref, 4 tab, 29 fig] https://www.jstage.jst.go.jp/article/jjasnaoe/20/0/20_1/_pdf Mon, A.A., Suzuki, K., Hinok, T. English

This paper describes a hull form improvement of an innovative low-speed Ultra Large Block coefficient Ship (ULBS). A hull form optimisation method for reducing wave-making resistance and wave-breaking at the bow using a nonlinear programming method (NLP) based on the Rankine source method is discussed. In the optimisation process, wave-making resistance coefficient, surface integrals of the square of free surface elevations and free surface disturbance function D(x,y)-values are selected as the objective functions. Bow-body shape is optimised under the prescribed design constraints based on the present method. Numerical examples are given for unconventional ULBS. The three improved hull forms for the corresponding objective functions are obtained by optimal designs which indicate that the objective functions are reduced distinctly. In order to verify the present optimisation method based on the potential solver, the flow characteristics around the initial and bow optimised hull forms are analysed by using Computational Fluid Dynamics analysis based on the Navier-Stokes solver. Comparisons of the computed resistance coefficients, pressure and velocity distributions of the initial and bow optimised hull forms are presented. It is confirmed that simulation results based on the viscous flow solver show reasonable agreements with the numerical results based on the Rankine source method for the bow optimised hull forms.

Bow form Computational fluid dynamics Hull form Optimisation

2015061265

Preliminary hull form planning for non-ballast water ship and minimal ballast water ship (1st report). Journal of the Japan Society of Naval Architects and Ocean Engineers, v 20 2014, p 21 [6 p, 11 ref, 15 fig] https://www.jstage.jst.go.jp/article/jjasnaoe/20/0/20_21/_pdf Shingo, S. Japanese

This is the first report of preliminary hull form planning for a Non-Ballast Water Ship (NOBS) and Minimal Ballast Water Ship (MIBS). Ships having large block coefficient (CB) like crude oil tankers and bulk carriers need huge amount of water ballast to keep proper propeller immersion and forward draught to operate in rough sea condition. Ballast water is necessary and useful for the safety operation, whereas it makes ship heavier and inferior in propulsion performance. And ballast water will need to be cleaned by the ballast water treatment system which is approved in accordance with IMO's guideline in the near future. A reduction of water ballast is also desirable to prevent ocean pollution. NOBS/MIBS has a unique hull form having V-shaped/convex bottom, and can keep sufficient draught to navigate safely on empty cargo condition even in rough sea without/with less water ballast. As a result of unique hull form, NOBS/MIBS has a very small midship coefficient in comparison to that of a conventional ship. Such unique principal particulars bring difficulties to investigate preliminary design of principal particulars for NOBS/MIBS. In this paper, the author proposes some simple procedures to estimate propulsive performance for NOBS/MIBS using neural network and measured data fitting. As the accuracy of these procedures and results are confirmed in the projects of NOBS/MIBS development, it can be the same level as that for conventional ships.

Ballast water Hull form Propulsive performance

467 ABSTRACTS

2015061266

Structural optimisation of the mid-ship section by applying genetic algorithm and response surface method. Journal of the Japan Society of Naval Architects and Ocean Engineers, v 20 2014, p 109 [9 p, 6 ref, 7 tab, 8 fig] https://www.jstage.jst.go.jp/article/jjasnaoe/20/0/20_109/_pdf Mori, S., Xin, S., Et al Japanese

When estimating the construction cost of ship structures in the early design stage, it is important to decide roughly the arrangement and scantling of structural member of mid ship section in a short examination time. The technique for determining the optimal structure of a midship section using a genetic algorithm etc. has begun to be applied in actual design. However, these optimisation techniques seem not to be able to obtain the optimal structure within practical computation time. Moreover, the Common Structural Rule published in April 2006 by IACS, requires FEM calculation for estimating the stress of a double bottom member, such as bottom plate, inner bottom plate, transverse webs, and girders. If the FEM analysis is to be included directly in an optimal structural calculation program, it will require a large amount of computation time. In this research, FEM calculations for typical scantling members were performed and the response surface for estimating the stress of the members is produced. By including this response surface in the optimal design calculation using a genetic algorithm, the optimal structural calculation for the midship section was realized within a practical computation time. The availability of optimal calculation for structural members in mid ship section is presented by showing calculation results for a Handymax bulk carrier.

Genetic algorithms Midship sections Optimisation Response surface methodology

2015061267

Automatic routing system for multiple pipelines. Journal of the Japan Society of Naval Architects and Ocean Engineers, v 20 2014, p 221 [10 p, 9 ref, 11 fig] https://www.jstage.jst.go.jp/article/jjasnaoe/20/0/20_221/_pdf Ando, Y., Kimura, H. Japanese

During ship design, designers have to deal with all pipe-routes in order to generate practical piping layouts composed by the minimum cost value (i.e. interference with obstacles, the length of each pipe-parts, etc.). However, the routing task requires huge work hours because there are many regulations and functional design rules in the field. In this paper, the authors propose an automatic routing system for multiple pipe-routes. The proposed system aims to solve the complicated multiple routing problems and to improve the design work efficiency. In the routing problem for pipes, there are two major factors having the significant influence to final routing designs: the order of routing search and the selection from candidates of pipe-routes. The routing system is capable of handling these two factors by adopting the Touch and Cross method and simulated annealing method. The Touch and Cross method is a routing algorithm to find candidates including no interference with each path. Simulated annealing method is one of the optimisation methods to find a global optimum of a given function in a large search space. By combining these two methods, the routing system can reduce the influence of the search order and the selection problem. Therefore, it is able to find suitable pipe-routes automatically though there are no guarantees to find the best layouts. The routing system also uses Dijkstra's method as a routing method to find the optimal route efficiently. The performance of the system is demonstrated through several simulations.

Automation Layout Piping systems

ABSTRACTS 468

2015061268

A study on the optimisation of ship design process using wildcard GA. Journal of the Japan Society of Naval Architects and Ocean Engineers, v 20 2014, p 231 [12 p, 13 ref, 14 tab, 20 fig] https://www.jstage.jst.go.jp/article/jjasnaoe/20/0/20_231/_pdf Hamada, K., Fujii, R., Et al Japanese

The performance of the product and the design time are influenced by the design process. Therefore, it is very important to advance the design in an appropriate design process. However, the design process generally relies on the experiences of the designer and it is difficult to examine their characteristics. In this study, design process of ship principal particulars is optimised by using the optimisation technique. Moreover, the features of the optimised design processes are examined. The optimum design process is generated by using the Wildcard Genetic Algorithm which can deal with the uncertainty of product information. By executing the optimisation, two kinds of design processes are generated i.e. performance valuing process and feasibility valuing process. The characteristics of the optimised design processes are analysed by using a design support system in which dependency of the information and changes in the variation range of constraints and objective functions according to the progress of the design are visualized. In this paper, the optimisation method of the design process and the results of the optimisation are shown. Moreover, an overview of the design support system and features of the optimised design process are discussed. As a result, the effectiveness of the proposed system is confirmed.

Design process Optimisation

2015061269

Main particulars optimisation of a sea-going ferry for a given shipping route. Logistics and Transport, v 25 n 1, 2015, pp 57-62 http://www.logistics-and-transport.eu/index.php/main/article/view/382 Artyszuk, J., Gucma, S. English

The paper presents a two-stage optimisation approach of sea-going ferry main particulars intended for a particular route. The method is especially suited for

determining the owner's specific design requirements. The goal of the first stage is a maximisation of cargo capacity, mostly in terms of the total lane length. An empirical method based on the fleet statistics of existing ferries is used throughout the stage one. The objective function of the second stage is the capital and service costs of a ferry, which are to be minimised. The solution of the latter optimisation will essentially involve a ship manoeuvring motions simulation

Ferries Manoeuvring Optimisation Ro/ro ships Ship design

2015061270

Application of the improved collaborative optimisation on ships’ conceptual design. Journal of Ship Mechanics, n 12, 2014, pp 1453-1459 http://www.cssrc.com/ Chen, C-h., Yao, Z-l. Chinese

The development of a multidisciplinary design optimisation method and its broad application prospects in ship design are presented. The collaborative optimisation is described in detail. According to its disadvantage, a dynamic penalty function method is proposed. It is based on the modification of the system level optimisation problem, and is turned into an unconstrained optimisation problem. It can reduce the difficulties and improve the calculation accuracy. A resistance and structural optimisation problem of certain SWATH is simplified and solved, and the final result lowers fuel consumption, and shows that this algorithm application in ship’s conceptual design is feasible.

Optimisation Ship design SWATH ships

469 ABSTRACTS

2015061271

The probabilistic approach for the damage stability assessment: An application case in the specific field of megayacht units. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 118, p 1123 [6 p, 7 ref, 2 tab, 5 fig] http://www.crcpress.com/product/isbn/9781138027275 Spigno, M., Gualeni, P., Et al English

In recent years there has been a huge renewed activity in the field of safety regulations, especially for the damage stability assessment of passenger vessels. After the shift from deterministic to probabilistic approach, several urgent matters aroused in naval architects’ minds as well as in those of anyone in charge of safety assessments. One of the possible interesting points of discussion is “How to assess the ship’s damage stability in a preliminary design phase?” In fact, the probabilistic approach for the residual stability evaluation in a damaged situation requires a high level of detail and data which are usually not available in a preliminary design phase. Moreover, even if one had such information, it would be very hard to properly and promptly estimate their complex interaction and influence on the final outcome in terms of stability as well as to evaluate the effects of their possible change in a more advanced design phase. One of the aspects causing a great impact on assessment is the attention to be paid to the fire protection subdivision during the damages definition phase within the probabilistic approach.

Damage stability Motor yachts Probabilistic methods Ship design

2015061272

A design summary of a state of the art drilling semi-submersible. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 123, p 1161 [7 p, 3 ref, 2 tab, 11 fig] http://www.crcpress.com/product/isbn/9781138027275 Laranjinha, M., Kvillum, T. English

This paper summarizes the methodology utilized by Agility Projects’ engineering groups and the main challenges faced during the different design states of a 6th generation semi-submersible drilling unit. The paper is mainly intended to provide an industry point of view on the design and engineering work, and the challenges that have to be faced in order to be able to develop a state of the art offshore drilling vessel. The example is a drilling rig design currently under construction as the Hai Yang Shi You 982 (HYSY982) for the Chinese offshore operator China Oilfield Services Ltd. (COSL).

Platform design Semisubmersible rigs

2015061273

Improvement in resistance performance of a medium-sized passenger ship with variation of bulbous bow shape. Journal of the Society of Naval Architects of Korea, v 51 n 4, August 2014, p 334 [8 p, 13 ref, 5 tab, 13 fig] http://www.koreascience.or.kr/article/ArticleFullRecord.jsp?cn=DHJSCN_2014_v51n4_334&ordernum=9 Yu, J-W., Lee, Y-G., Lee, S-H. Korean

Due to the rise of international oil prices, with the continued increase of vessel operating costs, profitability has gradually deteriorated in South Korean ferry shipping. Therefore, it is necessary to improve the resistance performance of passenger ships. The goose neck bulb can be one of the methods to improve the resistance performance of passenger ships. The goose neck bulb has been applied to passenger ships operated in Europe and large cruise liners. But there is no application example of a passenger ship to be operated on a regular basis in the sea near Korea. It is needed to provide reference data that can be applied efficiently to a goose neck bulb on medium-sized passenger

ABSTRACTS 470

ships. This study, intended for the medium-sized passenger ship operated short international routes, presents the design of the hull form to which a goose neck bulb has been applied. The resistance performance of the designed hull is confirmed by numerical simulation. The numerical simulation is performed while changing the local shape of the goose neck depending on the bulb parameters. This study finds bulb parameters and their range that can affect the resistance performance.

Bulbous bows Hull form Passenger ships Resistance Ship design

2015061274

A new method for determining the design sloshing loads for LNG FPSOs. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1A: Offshore Technology, Paper No. OMAE2014-23730 [15 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911392 Paik, J.K., Lee, S.E., Et al English

The aim of this study was to develop a new method for determining nominal values for sloshing loads in the design of storage tanks in LNG FPSO (liquid natural gas, floating production, storage and offloading units). Details of the procedure are presented in a flow chart showing the key sub-tasks. The applicability of the method is demonstrated using an example of a hypothetical LNG FPSO operating in a natural gas site off a hypothetical oceanic region. It is concluded that the developed method is useful for determining the design sloshing loads of storage tanks in ship-shaped offshore LNG installations in combination with virtual metocean data and operational conditions.

Design loads FPSOs LNG tanks Sloshing

2015061275

Alternative environmental contours for marine structural design: a comparison study. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4542-4. Volume 4A: Structures, Safety and Reliability, Paper No. OMAE2014-23252 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911612 Vanem, E., Bitner-Gregersen, E.M. English

A new approach to estimating environmental contours has recently been proposed, where the contours are estimated in the original physical space by Monte Carlo simulations from the joint distribution directly rather than applying the Rosenblatt transformation. In this paper, the new and the traditional approach to estimating the contours are presented and the assumptions on which they are based are discussed. The different results given by these two methods are then compared in a number of case studies. Simultaneous probability density functions are fitted to the joint distribution of significant wave height and wave period for selected ocean locations and, for each area, environmental contours are estimated for both methods. The chosen locations are characterised by different wave climates. Thus, the practical consequences of the choice of approach are assessed. Particular attention is given to mixed sea systems, i.e. a combination of wind sea and swell. In these situations, the new approach for environmental contours may fail to identify realistic conditions along some parts of the contours while for other wave conditions the contours are quite similar. The paper also briefly discusses possible ways of amending the new approach to estimating the contours to obtain more realistic conditions all along the contour lines.

Design Environmental conditions Offshore structures

471 ABSTRACTS

2015061276

Ship-hull shape optimisation with a T-spline based BEM–isogeometric solver. Computer Methods in Applied Mechanics and Engineering, v 284, 1 February 2015, pp 611-622 http://www.sciencedirect.com/science/article/pii/S0045782514004009 Kostas, K.V., Ginnis, A.I., Et al English

This work presents a ship-hull optimisation process combining a T-spline based parametric ship-hull model and an Isogeometric Analysis (IGA) hydrodynamic solver for the calculation of ship wave resistance. The surface representation of the ship-hull instances comprise one cubic T-spline with extraordinary points, ensuring C2C2 continuity everywhere except for the vicinity of extraordinary points where G1G1 continuity is achieved. The employed solver for ship wave resistance is based on the Neumann–Kelvin formulation of the problem, where the resulting Boundary Integral Equation is numerically solved using a higher order collocated Boundary Element Method which adopts the IGA concept and the T-spline representation for the ship-hull surface. The hydrodynamic solver along with the ship parametric model is subsequently integrated within an appropriate optimisation environment for local and global ship-hull optimisations against the criterion of minimum resistance.

Hull form Optimisation Wave resistance

2015061277

A virtual look at ergonomic design. Ship & Boat International, March/April 2015, p 34 [3 p, 2 ref, 3 fig] http://www.rina.org.uk/sbi.html No author given English

Advances in digital human modelling (DHM) software are enabling naval architects and designers to factor the ‘human element’ into ship designs in a manner that could save significant time and cost. In this article, researchers from the European Boat Design Innovation Group (EBDIG) reveal how they

have applied this technology in the field of crew transfer vessel wheelhouse design.

Computer-aided design Crew boats Human factors engineering Wheelhouses

2015061278

Meeting native expectations. Ship & Boat International, March/April 2015, p 46 [3 p, 1 tab, 3 fig] http://www.rina.org.uk/sbi.html No author given English

As tragic as the recent spate of tourist boat accidents in Thailand have been, one positive outcome is that the country’s naval architects, boat builders and authorities have banded together to raise public awareness of the problem, and to develop solutions. This article discusses Albatross Marine Design’s AT47 ‘speedboat’ project which visualises the creation of a 14.3m x 3.8m monohull, with a fully loaded displacement of 13 tonnes, which would comply with ISO Small Craft Standards and partly (in terms of general layout and stability) with the IMO Code for High Speed Craft. The aim is to create a vessel type that increases safety levels through a balance of “smart planning and design margins”, and “without significant expenses, nor investment in formal classification”.

Boats High speed vessels Ship design

ABSTRACTS 472

1.3 SHIPBUILDING TECHNOLOGY/CONSTRUCTIONAL TECHNIQUES

2015061279

Bonded joints in shipbuilding: A technological approach to the characterization of actual performances. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 60, p 575 [9 p, 5 ref, 7 tab, 14 fig] http://www.crcpress.com/product/isbn/9781138027275 Succio, D., Rizzuto, E., Et al English

The work reviews the state of the art of the use of bonded joints in shipbuilding, and describes motivations, features and results of an experimental research program aimed at characterizing actual performances attainable in bonded joints by use of several adhesives, currently available on the market, applied in realistic conditions. Joints with different specifications, realized with substrates in steel and in aluminium alloys, are examined. Tests carried out on specimens realized with an adhesive layer thickness realistic for shipbuilding, have been carried out. The effect of marine environment is also considered, comparing results of mechanical test on un-exposed specimens with those obtained on specimens exposed to environmental effects such as salt mist spray and ultra-violet rays. The final aim of the program is to apply the selected bonding procedure to a real case in order to check the applicability of the joint.

Bonded joints Shipbuilding

2015061280

Max-plus-algebra bases scheduling of shipbuilding lines for tandem construction of a pair of ships. Journal of the Japan Society of Naval Architects and Ocean Engineers, v 20 2014, p 205 [16 p, 7 ref, 5 tab, 32 fig] https://www.jstage.jst.go.jp/article/jjasnaoe/20/0/20_205/_pdf Kajiwara, H., Hitoi, Y., Et al Japanese

The paper is concerned with a just-in-time scheduling problem of block-assembly lines conveyor for tandem construction of a pair of ships in a shipyard. The

blocks fabricated are stocked for pre-fitting and painting works and they are provided to the pre-erection area. It is not easy to schedule the block-assembly lines in order to avoid stock overflow and to realize the just-in-time arrivals to the pre-erection area. In a conventional push type scheduling, there are many idle days in the stocking period. Therefore the problem can be formulated as minimizing these idle days such that constraints of conveyor plates and stockyard capacities are satisfied under a dispatching rule for assembled order. In the paper, a new method to solve the problem is proposed, which requires a linear inequality represented by Max-Plus algebra. A pull-type scheduling is obtained as its maximal solution. Based on the scheduling results applied to the shipyard, the effectiveness and limitations are discussed.

Assembling Scheduling Shipbuilding

2015061281

Weld exclusive. Ship & Boat International, March/April 2015, p 50 [3 p, 4 fig] http://www.rina.org.uk/sbi.html No author given English

This article describes a patented boatbuilding system, developed by Cape Marine Australia, which allows customers to order customised shallow draught vessels that can be assembled by welders from pre-fabricated components, ‘Lego-style’, in as little as 48 hours.

Assembling Prefabrication Shallow draft vessels Workboats

473 ABSTRACTS

2.1 POWER SOURCES AND FUELS

2015061282

The vessels smart grid concept. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper III-7, p 197 [7 p, 25 ref, 3 fig] http://www.int-nam.yildiz.edu.tr/2014/ Yiğit, K., Karakaş, A., Et al English

Nowadays, energy efficiency has become more important issue due to some factors such as depletion of fossil fuels, climate change, increasing energy demand, energy reliability, and technological advances. It is also necessary to take account the energy efficiency in the maritime sector as well as the other sectors. This study considers the role of vessels in smart grid concept which is defined as future of the power grid. There are several smart grid projects including vessels in the literature. These projects focus on reduction of CO2 emissions, energy efficiency and renewable energy applications for vessels. It is also very important to use an energy management algorithm for electrical energy consumption to achieve the efficiency on vessels.

Electric power Energy conservation Grids

2015061283

Waste Heat Recovery systems from marine diesel engines: Comparison between new design and retrofitting solutions. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 76, p 735 [8 p, 6 ref, 4 tab, 6 fig] http://www.crcpress.com/product/isbn/9781138027275 Altosole, M., Laviola, M., Et al English

Waste Heat Recovery (WHR) systems are more and more common on board new commercial ships, and their good efficiency now is to be considered also for retrofitting solutions. The paper describes the performance and cost analysis of a WHR system, based on an auxiliary steam turbine for electric power

generation, supplied by the steam plant adopted for the waste heat recovery from the exhaust gas of the main diesel engines. The application concerns a passenger ship, powered by six diesel generators to drive the electric propulsion motors, to feed the several auxiliary systems and to fulfill the whole hotel service demand. The analysis is carried out on the basis of a comparison between new design and retrofitting solutions for the same application, considering that a complete optimisation design process is really possible only for an “ex novo” ship project. In fact, the present paper considers the minimum retrofitting intervention (mere addition of turbo-generator and vacuum condenser) where the optimisation process can be reasonably restricted to the steam turbine sizing, while for a new ship it can be extended to the selection of the whole machinery. The different results are based on an optimisation numerical code, developed by the authors in Matlab software environment, and they are analysed in terms of performance and cost, in order to provide helpful guidelines to assist ship-owners and shipbuilders in making their decisions.

Cost benefit analysis Diesel electric propulsion Heat recovery

2015061284

Assessment of steam cycle layouts for COGAS ship propulsion systems. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 77, p 743 [12 p, 12 ref, 5 tab, 14 fig] http://www.crcpress.com/product/isbn/9781138027275 Benvenuto, G., Laviola, M., Campora, U. English

Combined gas and steam turbine (COGAS) power plants are estimated currently to be the most efficient type of power machinery for terrestrial applications. Their use for marine propulsion is so far limited, mainly in consideration of the investment costs. However the possibility of reducing pollutant emissions and fuel consumption (and therefore operating costs) could favour in a near future the diffusion of these systems in the shipping sector. In this paper, starting from the performance characteristics of a marine gas turbine, four steam plants layouts are considered, optimised and compared by means of a mathematical model developed by the authors. Thus it is possible to obtain

ABSTRACTS 474

information regarding the best solutions for a feasible COGAS ship propulsion system. The presented results take into account not only the overall energy conversion efficiency of the installation, but also other important issues typical of marine applications such as: plant dimensions, weights and economic considerations.

Combined cycle power plants Layout Steam power plants

2015061285

Ethane is the fuel. Diesel & Gas Turbine Worldwide, v 47 n 2, March 2015, p 32 [3 p, 2 fig] http://www.dieselgasturbine.com/ Svensson, B. English

Ocean Yield ASA, the Oslo-based shipowner, has placed orders for three LEGCs (Liquefied Ethylene Gas Carriers) of 36,000 cbm capacity, to be built at Sinopacific Offshore & Engineering, China. Each will be powered by a single MAN B&W ME-GI low-speed, dual-fuel engine. The engines will run on ethane, which ethylene carriers are also equipped to transport, and represents the first time ethane has been used as fuel to propel an oceangoing vessel.

Ethylene Gas carriers

2015061286

Development of a model for the prediction of the fuel consumption and nitrogen oxides emission trade-off for large ships. Energy, v 80, 1 February 2015, pp 545-555 http://www.sciencedirect.com/science/article/pii/S036054421401367X Larsen, U., Pierobon, L., Et al English

The international regulations on fuel efficiency and NOx emissions of commercial ships motivate the investigation of new system layouts, which can comply with the regulations. In combustion engines, measures to reduce the fuel consumption often lead to increased NOx emissions and careful consideration of this trade-off mechanism is required in the design of marine propulsion systems. This study investigates five different configurations of two-stroke diesel-based machinery systems for large ships and their influence on the mentioned trade-off. Numerical

models of a low-speed two-stroke diesel engine, turbochargers and an ORC (organic Rankine cycle), are used for the optimisation of the NOx and fuel consumption at design and part-load conditions, using a multi-objective genetic algorithm. Moreover, the effects of engine tuning and exhaust gas recirculation are investigated. The results suggest that increased system complexity can lead to lower fuel consumption and NOx. Fuel consumption reductions of up to 9% with a 6.5% NOx reduction were achieved using a hybrid turbocharger and organic Rankine cycle waste heat recovery system.

Diesel engines Emissions Fuel consumption Heat recovery Two stroke engines

2.2 EQUIPMENT AND INSTALLATIONS

2015061287

Model-based performance assessment and optimisation of waste heat recovery systems for containerships. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Stefanatos, I.C., Dimopoulos, G.G., Kakalis, N.M.P. English

Waste heat recovery (WHR) is a promising solution for efficient, cost-effective and environmentally friendly power generation onboard oceangoing vessels. However, the installation of such systems increases significantly the complexity of the power-plant with regards to machinery space and weight limitations, safety and operational constraints and higher capital costs. In addition, design parameters may change influencing the operational behaviour of the system, e.g. slow steaming. To address simultaneously such issues, a techno-economic approach able to take into account the design, operation and control of the entire integrated marine energy system throughout its mission profiled is required. The paper presents the techno-economic assessment and optimisation of WHR options for a 13000 TEU containership, currently under slow-steaming, via mathematical modelling and simulation techniques. A model of the integrated system of the vessel has been developed using a modular library of reconfigurable component models suitable for design,

475 ABSTRACTS

performance and transient and payback period. However, the optimal configuration and potential gains strongly depend on the operational profile and slow steaming conditions. The optimal operation of the WHR-system in partial loads was also estimated and its minimum operational load was calculated, via model-based approaches complex integrated systems can be successfully investigated providing effective decision support to system designers, integrators and owners/operators.

Containerships Heat recovery Slow steaming

2015061288

Electric propeller shaft system torsional vibration analysis. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper VI-5, p 519 [9 p, 10 ref, 4 tab, 4 fig] http://www.int-nam.yildiz.edu.tr/2014/ Beşik, M., Demirel, H., Et al English

This paper aims to calculate the marine electrical propulsion system shafting torsional vibration with gears transmission. Gear system dynamics theory has been introduced into the torsional vibration calculation of the marine shafting and the vibration equations with gears transmission were established by using the lumped parameter model. Then a dynamic simulation has been done in MATLAB software, in which the natural frequency of the system has been obtained from the simulation curve. The frequency and amplitude of vibration torque obtained by the simulation is calculated by the frequency analysis. Thus, the resonance condition of the rotor shaft between turbine and generator can be evaluated by comparing the natural frequency and the analytic value obtained by the simulation study.

Propeller shafts Torsional vibration

2015061289

A fundamental study on development of new higher performance anchors for safe maritime transportation. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 69, p 663 [7 p, 6 ref, 2 tab, 16 fig] http://www.crcpress.com/product/isbn/9781138027275 Masuda, M., Otani, I., Minami, K. English

Anchors of various types and performances have been developed over the centuries. For example, JIS types and AC-14 types are mostly applied to Japanese ships at present. The purpose of this research is to develop a higher performance anchor. Therefore, an anchor water tank experiment was carried out. The candidates for an experiment are JIS type, AC-14 type and DA-1 type anchors. As a result, the anchor evaluation method for new higher performance anchor development was created.

Anchors

2015061290

Air lubrication system tested on a products tanker. Tanker Operator, v 14 n 4, March 2015, p 30 [2 p, 2 fig] http://www.tankeroperator.com/AllMagazine.aspx No author given English

Silverstream Technologies and Shell recently conducted successful sea trials of an air lubrication technology for ships, the patented Silverstream System. The sea trials, independently verified by Lloyd's Register Ship Performance Team, show net energy efficiency savings in all analysed cases, the company claimed. The system was installed on the 40,000 dwt products tanker Amalienborg. The trials showed net average energy efficiency savings of 4.3% and 3.8% for the vessel in ballast and laden conditions. The Silverstream system produces a thin layer of micro-bubbles that creates a single ‘air carpet’ for the full flat of bottom of the ship. This

ABSTRACTS 476

reduces the frictional resistance between the water and hull and improves the vessel’s operational efficiency, reducing fuel consumption and associated emissions.

Air lubrication Fuel conservation Products tankers Ship efficiency

2015061291

Eliminating PM from the mix. Ship & Boat International, March/April 2015, p 28 [3 p, 1 fig] http://www.rina.org.uk/sbi.html No author given English

While the main focus regarding emission reduction may be centred on NOx, SOx and CO2, it is argued that similar attention needs to be paid to carcinogenic particular matter (PM). This article describes Eliminator, a hydrogen-based system to curb PM levels. Initial tests of have proven the system capable of reducing emissions of cancer-causing particulate matter by 22%.

Particulate control

2015061292

Water, water everywhere. Ship & Boat International, March/April 2015, p 38 23 p, 1 fig] http://www.rina.org.uk/sbi.html No author given English

Exorbitantly priced propeller shaft bio-lubricants may have been approved by authorities such as the US EPA, however this article argues that seawater can do the job for a fraction of the lifetime costs.

Propeller shafts Seawater Water lubrication

2015061293

Bridging the future. The Naval Architect, March 2015, p 36 [2 p, 1 fig] http://www.rina.org.uk/tna.html No author given English

Rolls-Royce, working with the VTT Technical Research Centre of Finland and Alto University, has

set out a vision for a future intelligent bridge, which VTT says could be a reality by 2025. It is known as the future operator Experience concept (oX), and is initially for tugs, cargo ships and platform supply vessels. The concept will utilise the latest digital technologies to create safer and more energy efficient ship operations. oX envisages an environment with smart work stations, which automatically adapt to the individuals personal preferences.

Artificial intelligence Bridge remote control Bridges (ships)

2.3 MAINTENANCE, REPAIR AND CONVERSION

2015061294

Strength and stability considerations of an ageing oil tanker converted to support the mooring of ultra-deep water floating units. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 125, p 1177 [8 p, 4 ref, 10 tab, 24 fig] http://www.crcpress.com/product/isbn/9781138027275 Tapia, M., Kaleff, P., Et al English

To respond to the needs for operational supplies in the mooring of ultra-deep water semi-submersibles, the conversion of an ageing single hull tanker was proposed in which the transverse bulkheads in the centre tank area were eliminated and the corresponding deck portion was lowered to provide a single loading space served by a hoisting crane located at approximately mid length. The structural capacity of the proposed conversion was tested against rule defined vertical bending and combined horizontal bending and torsion. Whereas torsional strength was assured, longitudinal strength was rendered insufficient due to the significant reduction of the midship section modulus. It was however shown that longitudinal strength might be assured if the maximum still water bending moment was kept at roughly half of its rule value. To achieve this and comply with the static stability requirements, all loading conditions, as well as the corresponding loading steps, were adjusted with suitable ballasting

477 ABSTRACTS

by means of a trial and error procedure. The results are presented in the form of a simplified loading manual.

Ageing ships Ship conversion Stability Structural strength Tankers

2.4 CARGOES AND CARGO HANDLING

2015061295

Risk analysis of undesirable events during transport, loading and unloading of Liquefied Natural Gas (LNG) on ships. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 68, p 655 [8 p, 23 ref, 5 tab, 3 fig] http://www.crcpress.com/product/isbn/9781138027275 Martins, M.R., Pestana, M.A., Et al English

This study presents a summary of a quantitative consequence analysis of undesired events that can occur during maritime transport, loading and unloading of Liquefied Natural Gas (LNG), aiming the development of a complete risk analysis concerning these operations. In this phase, the hazardous events have been identified, the available models and software have been carefully studied, and a case study has been analysed. The most severe identified events were those related to leaks which can lead to fires and explosions. The quantification of consequences has been concluded and the estimation of the frequencies of the postulated events is now under study in order to calculate risk and propose measures to lower, where possible, the identified risks.

LNG handling LNG transportation Risk analysis

2.5 PORTS AND WATERWAYS

2015061296

History of ship fires in ports. The importance of preventive measures and training. International Conference on Fire at Sea, 26-27 March 2014; London, UK. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Incertis, D. English

This paper reviews vessel fires occurring in ports throughout history and the measured taken to prevent or cope with them.

Ports Shipboard fires

2015061297

Strategic levers of port authorities for industrial ecosystem development. Maritime Economics and Logistics, v 17 n 1, March 2015, pp 79-96 http://www.palgrave-journals.com/mel/journal/v17/n1/abs/mel201428a.html Hollen, R.M.A., Bosch, F.A.J. van den, Volberda, H.W. English

Major ports such as Rotterdam, Antwerp, Houston and Singapore’s Jurong Port host large industrial complexes of (petro) chemical and other energy-intensive process industry firms. Port authorities face the challenge to contribute to both greater international competitiveness and better environmental performance of these complexes. The development of industrial ecosystems, in which firms located in port areas use one another’s residual energy and chemical effluents as input for their own production process, appears to be a promising strategic response to this challenge. This article contributes to port research by examining how port authorities can foster this development within their port-industrial complex. A case study of the Port of Rotterdam is presented to empirically capture how the Port of Rotterdam Authority has done so in the last decade by strategically making use of two generic types of policy instruments: (i) investments in

ABSTRACTS 478

physical and knowledge infrastructure and (ii) land allocation. On the basis of the case study and previous literature, a set of strategic levers of port authorities is derived to foster industrial ecosystem development. Implications and challenges for port authorities are discussed.

Ecosystems Port authorities

2015061298

Towards a sustainability management system for smaller ports. Marine Policy, v 54, April 2015, pp 59-68 http://www.sciencedirect.com/science/article/pii/S0308597X14003534 Kuznetsov, A., Dinwoodie, J., Et al English

Larger ports routinely deploy environmental management tools but systematic sustainability management in smaller ports is rare. Accordingly, this paper assesses the sustainability needs of smaller UK ports in Cornwall and Devon, a case-study, and proposes a systematic method for identifying and managing them. The development and deployment of a Port Sustainability Management System for smaller ports in an environmentally sensitive but economically peripheral UK area is discussed. In-depth collaboration with Harbour Masters to identify sustainability management practice revealed few applications of the theoretical elements of triple bottom line accounting. Rather, semi-structured interviews unearthed the essential elements of port management and facilitated mapping of the forces which underpin port sustainability practices. A constructivist grounded theory approach identified emerging concepts, common patterns and sustainability themes, which were synthesised into a Sustainability Management System based on 11 indicators of knowledge criteria and a self-scoring mechanism. Adopters reported a more proactive stance towards sustainability and safeguarding of local communities, improved understanding, and more effective discourse with stakeholders. Benefits spanned port improvements; awareness of progress, performance, strengths and weaknesses; enhanced

communication and reporting; and improved thought processes. Almost all reacted positively and identified multiple benefits, equating to two new jobs in each port.

Environmental protection Port management Small size

2015061299

LNG vessels will run through it. Diesel & Gas Turbine Worldwide, v 47 n 2, March 2015, p 22 [4 p, 3 fig] http://www.dieselgasturbine.com/ Slater, D.J. English

This article looks at the Panama Canal expansion and the impact it will have on the LNG trade.

LNG carriers Panama Canal

2.6 COASTAL/OFFSHORE ENGINEERING AND MARINE RENEWABLE ENERGY

2015061300

Feasibility study of top-tensioned production riser system in South China Sea. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume II, p 210 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Shi, Y., Cao, J., Et al English

Tension Leg Platforms (TLPs) have been widely used in oil and gas development. But to date, no TLP has been installed in the South China Sea. The environmental conditions in the South China Sea are not exactly the same as other sea areas, even though it is similar to the Gulf of Mexico. The feasibility of TLP application in the development of oil and gas field in the South China Sea needs to be demonstrated because of the soliton condition in the South China Sea, which is different from other areas such as the Gulf of Mexico. Top-Tensioned Riser (TTR) systems are a critical part of the TLP system, so the feasibility of TTRs in the South China Sea needs to be established. According to previous experiences in the

479 ABSTRACTS

South China Sea, a Soliton is treated as a kind of current impacted on offshore structures, which should be combined with the storm associated current in some load cases. This paper presents the TTR concept selection, wall thickness selection, strength and fatigue analysis (including VIV fatigue and wave induced fatigue), and interference analysis. The study shows that a single casing riser system can be designed with adequate strength, sufficient fatigue life, seabed and reasonable well bay layout that prevent clashing. It is concluded that the TTR system in the South China Sea is feasible, which may not only benefit future study and design of TTRs, but also help accelerate the use of TLPs in the South China Sea.

Fatigue life Feasibility Risers Strength Tension leg platforms

2015061301

Metocean survey of deepwater areas in the South China Sea for a semisubmersible drilling platform. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume III, p 431 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Guo, Y., Zeng, H., Et al English

This paper introduces a process on the metocean survey of a deepwater area in the South China Sea, which is as a basic data for the design and construction of a semisubmersible drilling platform. The marine environment of the South China Sea is extremely harsh and the semisubmersible drilling platform will be operated in very poor conditions. So it is necessary to get more metocean data as basic parameters before the design of a semisubmersible drilling rig. To acquire such data, the engineers carried out a set of surveys and obtained a lot of in-situ metocean data, including not only the weather environment data but also marine environment data, such as the height and frequency of the waves, the current velocity in the different sea depths, and the variational laws of a metocean data with seasons in a year and so on. In addition, engineers also processed these actual data by a related mathematical method and obtained a set of parameters as basic environmental data to design a new semisubmersible drilling rig. During the surveys the engineers found

the phenomenon of a soliton that occurred uniquely in the South China Sea.

Deepwater Meteorological data Oceanographic data Semisubmersible rigs 2015061302

The role of simulation in the offshore industry. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper I-4, p 55 [10 p, 24 ref, 8 fig] http://www.int-nam.yildiz.edu.tr/2014/ Bertram, V. English

An overview of simulations for assorted advanced engineering analyses in the offshore industry is given, focussing on the benefits for the business processes of the customers. The analysed structures include fixed and floating offshore platforms, related ships such as supply vessels, and selected equipment. The role of assorted advanced simulations is illustrated by case studies.

Computational fluid dynamics Finite element method Offshore industries Simulation

2015061303

Prediction of performance and cavitation behaviour of horizontal axis marine current turbines. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper V-2, p 359 [13 p, 19 ref, 1 tab, 11 fig] http://www.int-nam.yildiz.edu.tr/2014/ Uşar, D., Atlar, M., Bal, S. English

Exploitation of ocean energy, by means of current energy converters such as horizontal axis marine current turbines, provides a predictable and sustainable resource for wide scale generation of electrical power. Providing new insights into marine current turbine hydrodynamics and cavitation phenomena, experimental and numerical studies have

ABSTRACTS 480

always been crucial for design and validation practices. In this study, hydrodynamic performance of a 400mm diameter horizontal marine current turbine model was tested in a 1.26m x 0.8m cavitation tunnel for over a range of tip speed ratios. Torque and thrust data, as well as cavitation visualizations for certain operating conditions were acquired. Experimental results indicated that the turbine was exposed to significant amount of sheet and cloud cavitation over the blades along with vortex cavitation at the blade tips. Inception and distribution of cavitation along the blades of the model turbine operating under the same test conditions were then modelled numerically using a vortex lattice method. The method was also applied to turbines tested previously and obtained results were compared with the data available. Satisfactory agreement with experimental data showed that the use of such prediction methods provide a reasonably accurate approach to estimate, therefore take the effects of cavitation into account in design and analysis of marine current turbines.

Cavitation Ocean currents Performance Turbines

2015061304

The tension leg semisubmersible (TLS): the hybrid TLP-semisubmersible floater with the spar response. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1A: Offshore Technology, Paper No. OMAE2014-23533 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911380 Mansour, A.M., Wu, C., Et al English

The Tension Leg Semisubmersible (TLS) floater is the second generation of the Free-Hanging Solid Ballast Semisubmersible (FHSB Semi) design. The FHSB Semi is the state-of-the-art design that maintains the advantages of the conventional Semisubmersibles and provides the motions of Spars. The FHSB Semi design is a conventional semisubmersible with an added feature of a Free-Hanging Solid Ballast tank (SBT) located deep below the hull keel level and connected through four groups of chains (on its four corners) to the semisubmersible hull. During the pre-service conditions, the chains are used to retract the SBT and maintain it at a close

proximity to the hull keel to facilitate the transportation and installation operations. Once the semisubmersible is moored in-place, the chain system is operated to lower the SBT to its desired elevation below the hull keel and maintain it permanently connected to the semisubmersible hull during the in-service condition. The SBT provides substantial in-water weight and added mass that significantly reduce the platform response and maintains the chains in tension. In this paper, detailed description of the Tension Leg Semisubmersible (TLS) design as the second generation of the FHSB Semi is presented. The paper also includes discussions on the proposed project execution plan for the TLS covering the fabrication, transportation and installation as well as the added risks and risk mitigations associated with the new semisubmersible design and execution. A case study is introduced where a TLS is used as a dry tree host for a field located at 6,000 ft of water in the central Gulf of Mexico (GoM) harsh environment.

Semisubmersibles Tension leg platforms

2015061305

Semi-active hydro-pneumatic heave compensator. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1A: Offshore Technology, Paper No. OMAE2014-23564 [6 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911382 Cuellar, W.H., Fortaleza, E. English

A hydro-pneumatic heave compensation system and a semi-active control are proposed according to the requirements drilling offshore of 6 km deep. The goal of this semi-active control is to maintain an acceptable performance of the system when the drill string mass changes, which also changes the performance of the hydro-pneumatic system. The control action is executed just by a servo valve, which modifies the system damping to optimise the compensator performance. This servo valve is the only moving part of the control system and therefore, this system is more robust regarding mechanical/

481 ABSTRACTS

electrical failures and it has low consumption energy. The results show a satisfactory frequency response of semi-active control when the drill string mass is changed.

Compensators Control systems Heaving Offshore drilling

2015061306

Lessons learned from Norwegian mooring line failures 2010-2013. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4542-4. Volume 4A: Structures, Safety and Reliability, Paper No. OMAE2014-23095 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911594 Kvitrud, A. English

15 failures of offshore mooring lines have occurred in the period 2010–2013 on the Norwegian Continental Shelf. The failures are cause by a mixture of overload, fatigue and mechanical damages. Failure statistics from the period 2010–2013 are presented and compared it with earlier statistics. In the period 1996–2005 a high number of cases were observed. The industry reacted reasonably, and the number of incidents was clearly reduced for several years. In 2010 the number of cases started to increase again, rising questions on how to improve again. Some of the old failure modes have disappeared, as dragging of anchors and failures of chains above 20 years of age. But several other failure modes have appeared or reappeared. Differences between different types of units are found. The failure frequencies are highly uncertain, but the failure rate from 2010–2013 have been in the order of magnitude: single line failures: 92*10−4 per line year and double line failures: 12*10−4 per line year. No triple line failures have occurred in 2010–2013, but using data from 2000–2013, the failure rate have been in the order of magnitude 2*10−4 per line year. The paper discusses possible changes in practice, regulations and standards, on quality of materials, maintenance, ALS-, FLS- and ULS-design.

Failure Mooring lines

2015061307

Comparing solutions of the coupled Boussinesq equations in shallow water. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 99, p 947 [8 p, 13 ref, 10 fig] http://www.crcpress.com/product/isbn/9781138027275 Mohapatra, S.C., Guedes Soares, C. English

The exact solitary wave solutions of one-dimensional nonlinear Boussinesq equations under shallow water condition over variable depth are described. The solitary wave solutions of one-dimensional and coupled nonlinear Boussinesq equations are obtained using the hyperbolic tangent method by considering only the equation of motion in shallow water. Further, the exact solutions of generalized coupled nonlinear Boussinesq equations are obtained based on first integral method. To understand the behaviour of the solitary wave solutions, several numerical results are analysed in different cases.

Mathematical models Shallow water Solitary waves

2015061308

On pressure disturbance waves in channels: Solitons, jets and ripples. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 100, p 955 [9 p, 29 ref, 10 fig] http://www.crcpress.com/product/isbn/9781138027275 Moreira, R.M., Chacaltana, J.T.A., Et al English

Pressure disturbance waves are computed via a fully nonlinear, unsteady, boundary integral formulation for various Froude and Bond numbers. Three moving pressure distributions are introduced in the numerical model to evaluate the produced near and far-field wave patterns in a channel. For Froude numbers equal to one, classical runaway solitons are obtained on the fore of the moving pressure patch whereas “stern” waves are radiated away. “Step-like” pressure distributions give different responses to the free-surface flow, with upward breaker jets and steeper “stern” waves. For supercritical and subcritical flows,

ABSTRACTS 482

steady solitons and stationary trenches moving at the same speed of the pressure distribution are obtained, respectively. Surface tension affects directly the free-surface flow: runaway solitons are suppressed; instead, a “building-up plateau” and a capillary wave train are formed ahead and on the rear of the moving pressure patch for long computational run-times. For supercritical flows, small-scale ripples and parasitic capillaries appear on the fore of the steady soliton; oppositely, for low Froude numbers, stationary trenches become shallower compared to the corresponding pure-gravity wave solutions. Nonlinear results show that near and far-field wave patterns are significantly affected by moving pressure distributions and surface tension.

Channels Pressure distribution Wave patterns

2015061309

Propagation of waves generated by a pressure disturbance moving in a channel. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 101, p 965 [7 p, 12 ref, 8 fig] http://www.crcpress.com/product/isbn/9781138027275 Rodrigues, S.R.A., Guedes Soares, C., Santos, J.A. English

This paper studies the effect of ship speed and water depth on the propagation of ship-generated waves. The ship is represented by a moving pressure distribution function at the free surface that is able to reproduce most of the phenomena involved in wave propagation. Results are obtained for a ship sailing along a coastal stretch made of a sloping bottom and a constant depth region. The results show that in the sloping bottom the crests of waves are bent along the slope and in the constant depth the standard Kelvin wave patterns can be found for the subcritical regime. In the critical regime the wave system is characterized by significant diverging waves and for a supercritical regime, the transverse waves disappear.

Channels Pressure distribution Ship speed Ship waves Wave propagation

2015061310

Application of the Ensemble Kalman Filter to a high-resolution wave forecasting model for wave height forecast in coastal areas. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 143, p 1349 [6 p, 25 ref, 6 tab, 7 fig] http://www.crcpress.com/product/isbn/9781138027275 Almeida, S., Rusu, L., Guedes Soares, C. English

Two different approaches related to the implementation of the Ensemble Kalman Filter (EnKF) in a wave modelling system SWAN (Simulating Waves Nearshore) are explored. A new methodology is tested first, in which the observations in the EnKF algorithm are replaced by the previously obtained analysis. The forecast is performed with one time-step advance, showing a high improvement in the accuracy of the significant wave height predictions. This technique can be applied to the guidance of ship movements in coastal and harbour approach areas. As a next step, an application of the Kalman filter is designed to improve the wave hindcast in terms of the main statistical parameters. In fact, this represents the beginning of a more theoretical and extended study related to assimilating data in wave hindcasts, where the filtered data corresponds to the best estimative of the underlying state of the system.

Coastal regions Kalman filters Wave forecasting Wave height Wave models

2015061311

Influence of a new quay on the wave propagation inside the Sines harbour. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 144, p 1355 [10 p, 16 ref, 2 tab, 15 fig] http://www.crcpress.com/product/isbn/9781138027275 Rusu, E., Guedes Soares, C. English

The objective of this work is to evaluate the wave propagation patterns in the basin of the Sines port, in

483 ABSTRACTS

particular studying the consequences of the installation of a new quay. A wave prediction system is focused on the target area in a multilevel nested scheme with increasing spatial resolution towards the coast. This system is based on WAM, for the wave generation at the level of the entire North Atlantic basin, and on SWAN, for the coastal transformation in the Portuguese continental near shore, which is running operationally at CENTEC. At the last computational level, with a resolution of 25 m in the geographical space, comprising also the harbour area, another spectral phase averaged model (STWAVE) was adopted as alternative to SWAN. As a subsequent step, based on historical data, an analysis of the wave climate in the vicinity of the Sines port was also performed. Following the results of this analysis, and considering various relevant wave patterns, simulations with the two spectral models were carried out in the same conditions, analysing in this way possible cases of direct wave propagation into the harbour area. Since the wave models results show that the main harbour basin is not totally protected to the direct wave propagation, the effect of building a new quay in the harbour area was also considered by estimating the sheltering effect induced by such a new protection.

Harbours Quays Wave propagation

2015061312

Feasibility study of the CECO wave energy converter. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 134, p 1259 [9 p, 6 ref, 1 tab, 13 fig] http://www.crcpress.com/product/isbn/9781138027275 Marinheiro, J., Rosa-Santos, P., Et al English

A feasibility study and proof of concept of a new and patented wave energy converter called CECO was performed. This device was designed to absorb both the kinetic and the potential wave energy. The behaviour of CECO was analysed for different wave conditions and operation modes, and two different techniques were used to evaluate the absorbed power. The relative capture widths determined for this not-

yet-optimised model are relatively high (up to 30%) and proved that this concept is promising, thus justifying further optimisation studies.

Feasibility Wave energy conversion

2015061313

Deep water installation, hydrodynamic aspects and practical considerations. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1B: Offshore Technology, Paper No. OMAE2014-23808 [12 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911399 Dijk, R. van, Zandwijk, K. van, Harmsen, E. English

The past decade has shown a fast growing subsea production market tending to complete factories on the sea floor involving ever more complicated infrastructure and increasing size and weight components to be installed. The water depth of this market typically ranges between 1000 and 3000m. This new subsea market triggers a need for increased deep water lowering capacity to enable safe, fast and efficient installation of this infrastructure. The authors’ company has gained extensive experience in the field of deep water installation over the past 15 years, ranging from complex mooring foundations to the installation of large subsea production units in up to 3000m water depth. This experience is used and further deployed in the specification of new and higher capacity deep water lowering systems for recent and upcoming investments. The paper shares a number of the contractor’s considerations with respect to a state-of-the-art deep water lowering system meeting the needs of today’s subsea production market. The paper addresses the challenges associated with the various stages of deep water installation, choices made in type of ropes (steel versus fibre), pros and cons of various floater types that can be used as an installation platform and the need for and effect of passive or active heave compensation.

Deepwater Installing Offshore platforms

ABSTRACTS 484

2015061314

Lifting analysis of subsea framework structures. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1B: Offshore Technology, Paper No. OMAE2014-23816 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911400 Søfteland, T.E., Skrunes, O.V., Karunakaran, D. English

Installation of subsea structures and equipment involves a lifting operation where the objects are exposed to large hydrodynamic forces when entering the oscillating sea-surface. During deployment, as the structure is lifted through the splash zone, snap forces due to slack or overload due to dynamic forces contribute to the maximum load experienced by the structure over the course of its design lifetime. This paper presents a method of how to verify the structural integrity of a subsea framework including determination of the maximum allowable sea-state in which the structure is safely installed. As well as describing an overall methodology for a subsea lifting analysis, hydrodynamic coefficients for cylinders in the splash zone is provided.

Heavy lift operations Installing Offshore structures

2015061315

Methodology and results of the sea trials for a second generation tidal converter. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 129, p 1213 [9 p, 18 ref, 1 tab, 22 fig] http://www.crcpress.com/product/isbn/9781138027275 López, A., Núñez, L.R., Et al English

Based on the main characteristics of second generation tidal power converters (TEC), a review of the present state of the art for this technology is presented. The main steps involved in the process of a TEC development (starting from the initial idea up to production) are described. Also, the applications of these devices are described through some significant tests, required according to the readiness level procedures of the technology. Later, the GESMEY

second generation TEC and the PROCODAC project are described; whose main objective has been the design, construction and sea trials of a 10 kW prototype. Finally, the objective and design for these tests are explained and the main results from the sea trials of power and operational procedures are shown.

Conversion Sea trials Tidal power

2015061316

Conceptual definition of one OTEC floating plant. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 130, p 1223 [8 p, 10 ref, 5 tab, 11 fig] http://www.crcpress.com/product/isbn/9781138027275 Núñez, L.R., Yraola, A.M., Et al English

This paper shows the result of a technical project that had as main objective the complete conceptual project of a new Ocean Thermal Energy Converter (OTEC), floating and with electrical generation capacity of 5 MW. The plant will be operated into oceanic locations with enough depth to get one oceanic thermal gradient of 24º that will be converted into electricity and transported to the shore by a submarine power cable. The device can be transported on float by a tug vessel to different places and during the operation of electrical generation can keep the right position with the thruster of its dynamic position system and also using its mooring system to keep the long cold water pipe to the sea bed. The plant uses a Rankine close cycle and can get 8.33 MW of gross electrical power with a thermodynamic efficiency of 7%.

Ocean thermal energy conversion

485 ABSTRACTS

2015061317

Analysis of wave heights and wind speeds in the Adriatic Sea. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 148, p 3893 [6 p, 14 ref, 2 tab, 12 fig] http://www.crcpress.com/product/isbn/9781138027275 Katalinić, M., Ćorak, M., Parunov, J. English

The study aims to determine mean annual wave heights and wind speeds in the Adriatic Sea. The Adriatic serves as a shipping route towards central Europe and a food and energy source for surrounding countries. Wave and wind climate information can serve as basis for design, research and policy making regarding ship safety and operability, potential renewable energy exploitation, design of off-shore installation etc. Mean annual wave height and wind speed values have been statically derived based on 43,274 ship sea state observations reported by the Hydrographical Institute of Republic of Croatia. This data has been digitalized and processed resulting in mean annual observed wave heights and corresponding wind speed values. Calm sea and no wind time percent periods have been calculated and wind-speed-to-wave-height correlations presented. The obtained results are discussed for accuracy, significant effects are listed and future work guidelines are given.

Adriatic Sea Sea state Wave height Wind conditions

2015061318

Model-based risk assessment of offshore operations. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4538-7. Volume 1B: Offshore Technology, Paper No. OMAE2014-24018 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911406 Lasche, C., Pinkowski, J., Et al English

Safety and dependability are major design objectives for offshore operations such as the construction of

wind farms or oil and gas exploration. Today processes and related risks are typically described informally and process specifications are neither reusable nor suitable for risk assessment. Here, the authors propose to use a specification language for processes. This specification language is integrated in a generic modelling approach in combination with an analysis tool and a tool to construct health, safety and environment (HSE) plans - a mandatory document for granting a construction/operation permit. Specifically, for each planned scenario a process is modelled, describing the detailed operation of the involved actors as well as the interaction with resources and environmental conditions. This process model is enriched with hazardous events which are facilitated by integration with an offshore operation generic hazard list, thereby giving access to expert knowledge for the specific situation to be planned. This in turn allows us to perform an automatic quantitative risk assessment using fault tree analysis. The authors exemplify the approach on a standard offshore operation of personnel transfer from an offshore building to another naval unit by modelling, annotating with hazards, performing the fault-tree analysis, and finally generating HSE plans.

Offshore engineering Risk analysis

2.7 SAFETY AT SEA

2015061319

Analysis on the effectiveness of fire safety equipment in resisting the spread of heat and smoke during fire accident on ro-ro-pax crossing ferry (case study on local Indonesian ferries). International Conference on Fire at Sea, 26-27 March 2014; London, UK. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Sunaryo, S. English

The percentage of marine fire accidents is considerably high in Indonesia, reaching about 41% of all major accidents, most of these occurred onboard ro-ro ferries. The heat and smoke from the fire usually spread to other spaces including passenger spaces, which made the passengers panic due to heat, low visibility, and inhale of toxic gases, that made them difficult to escape from the affected spaces. A study was carried out using fire simulation software with the aim to analyse the effectiveness of sprinklers, smoke exhaust and fresh air supply fans

ABSTRACTS 486

operated in the vehicle decks and passenger lunge in resisting the spread of heat and smoke in the ferry’s passenger lounge during the fire accident so that passengers would have enough time to evacuate to the safe place. Results of the simulations concluded that the existence of sprinklers could maintain the room temperature under 600 C, and the activation of smoke exhaust and fresh air supply fans could maintain the visibility for 30m, which means that the passengers are able to evacuate through escape routes.

Fire extinguishing systems Fire safety Ro/ro safety Smoke Visibility

2015061320

Effects of firefighting water on vessel’s floating condition and hull structure. International Conference on Fire at Sea, 26-27 March 2014; London, UK. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Ahlers, K., Schier, H. English

Ships in distress with a fire onboard can become subject to hazardous circumstances, if the common method to combat the fire with seawater is used. Passenger vessels might face a multiple free surface effect, for container vessels the additional loads of the firefighting water will heavily influence the residual strength of the heat-related weakened hull structure. This paper presents experience in the use of firefighting water onboard and draws attention to the critical points with respect to stability and strength of a vessel.

Firefighting Seawater Stability Strength

2015061321

Enhancing the global safety by situational awareness and ergonomic design. International Conference on Fire at Sea, 26-27 March 2014; London, UK. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Stefani, S. English

The paper discusses the innovations of safety monitoring and control systems and their capabilities to integrate the information the safety systems onboard in order to support the decision making process by the operator.

Control systems Decision making Monitoring Shipboard safety

2015061322

Fire risk analysis of a cutter suction dredger. International Conference on Fire at Sea, 26-27 March 2014; London, UK. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Twigt, M., Holland, C., Et al English

This paper presents a performance based fire risk assessment conducted during the design phase of a self-propelled cutter suction dredger that was recently built by Van Oord. The risk investigation encompassed a preliminary qualitative fire risk severity screening evaluation for all of the vessel compartments to identify those spaces associated with the highest fire risk.

Risk analysis Shipboard fires Suction dredgers

2015061323

Firefighting - challenges in Arctic conditions. International Conference on Fire at Sea, 26-27 March 2014; London, UK. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Wighus, R. English

Fire severity and explosion overpressure depends among other factors on the size of an enclosure and

487 ABSTRACTS

the air/fuel ratio. In well ventilated areas, gas is dispersed and the risk of large gas clouds with stoichiometric conditions is less frequent than in enclosed areas.

Arctic environment Firefighting

2015061324

Modelling fires on ships. International Conference on Fire at Sea, 26-27 March 2014; London, UK. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Wyse, S.G., Macpherson, G.B. English

Fires on ships pose a considerable risk during both operation and construction. Evaluating the effect of a fire can identify where additional mitigation is required to allow safe evacuation. The UK Royal Navy Queen Elizabeth Class Aircraft Carrier is currently undergoing construction, and fire defence systems are not operational. The benefit of installing smoke curtains as a risk mitigation option during this construction phase has been evaluated. The likely benefit of installing smoke curtains was quantified using Computational Fluid Dynamics, and the expected evacuation times of personnel during a large fire was assessed. By assessing the visibility and CO concentrations, the behavioural and physiological effects of the smoke on evacuating personnel could be quantified. The actual evacuation time from fire drills could then be directly compared to the modelled CO toxicity timescales. This demonstrated that the installation of well positioned smoke curtains resulted in significantly extended safe evacuation times. It also demonstrated that all stairwells would still remain safe evacuation routes. By considering the layout of a ship and identifying combustible quantities and locations, a ship design can be assessed and key risk areas identified. Modelling of the fire build-up, smoke and CO spread, allows an operator to see who will be most affected by the worst case fire. Operators can then compare this to evacuation simulations or tests and view mitigation from well positioned smoke curtains to ensure all personnel have a high chance of escaping unharmed.

Computational fluid dynamics Fire safety Shipboard fires Smoke

2015061325

Real time practice the missing link between fire management techniques taught and preventative measures and training learnt and applied? International Conference on Fire at Sea, 26-27 March 2014; London, UK. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Beckett, A. English

This paper presents an argument that there is a missing link between what a ship officer of tomorrow learns in the classroom today, and their ability to demonstrate through practical application these learnt skills in a real time simulated work environment when it comes to dealing with or preventing fire emergencies onboard a vessel.

Fire prevention Maritime education and training Shipboard fires

2015061326

Using the cutting extinguisher to fight fires at sea. International Conference on Fire at Sea, 26-27 March 2014; London, UK. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Lindstrom, J., Forsth, M., Ochoterena, R. English

The Cutting Extinguisher is a Swedish invention that is used to fight fires both on land and at sea. The main application is to fight the fire from a safe area.

Fire extinguishing systems Fire safety

2015061327

When is it too early to enter the engine room if flooded with smothering gas? International Conference on Fire at Sea, 26-27 March 2014; London, UK. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Dermen, O. English

Fixed gas fire extinguishing systems are very efficient fire suppression means when compartments on fire are kept closed long enough to prevent a secondary fire. This paper aims to find out if there is any relationship between the severity of re-entry

ABSTRACTS 488

conditions and the duration of the waiting period before and after the release of the smothering gas. It also intends to define a minimum period of time that is sufficiently long enough to safely enter the compartment without any re-ignition hazard.

Fire extinguishing agents Fire extinguishing systems

2015061328

Probabilistic ship collision risk and sustainability assessment considering risk attitudes. Structural Safety, v 53, March 2015, pp 75-84 http://www.sciencedirect.com/science/article/pii/S0167473014000940 Dong, Y., Frangopol, D.M. English

The disastrous consequences of ship collision necessitate the development of a collision risk-informed assessment procedure that ensures safety and functionality of maritime transportation systems. In this paper, an approach to assess the risk and sustainability associated with ship collision accidents is presented. The probability of ship collision is computed by taking into account traffic data and operational conditions. In this paper, sustainability is quantified considering the detrimental economic, social, and environmental consequences associated with ship collision. The economic, social and environmental metrics are evaluated separately and then social and environmental metrics are converted into an economic metric considering their associated monetary values. Epistemic and aleatory uncertainties associated with damage conditions of ships and consequences are incorporated in this methodology in order to provide a rational assessment of risk and sustainability. Risk attitudes are incorporated within risk analysis by utilizing utility functions. The approach is illustrated on a maritime transportation system in the Delaware River area considering the properties of damaged ships and maritime traffic in this specific region. Ultimately, this approach can aid the decision maker to make informed choices based on risk and sustainability considering risk attitudes.

Collision risk Probability Ship collisions

2015061329

Comparison study on AIS data of ship traffic behaviour. Ocean Engineering, v 95, 1 February 2015, pp 84-93 http://www.sciencedirect.com/science/article/pii/S0029801814004326 Xiao, F., Ligteringen, H., Et al English

AIS (Automatic Identification System) data provides valuable input parameters in ship traffic simulation models for maritime risk analysis and the prevention of shipping accidents. This article reports on the detailed comparisons of AIS data analysis between a Dutch case and a Chinese case. This analysis focuses on restricted waterways to support inland waterway simulations, comparing the differences between a narrow waterway in the Netherlands (the Port of Rotterdam) and a wide one in China (wide waterway of Yangtze River close to the Su-Tong Bridge). It is shown that straightforward statistical distributions can be used to characterize lateral position, speed, heading and interval times for different types and sizes of ships. However, the distributions for different characteristics of ship behaviours differ significantly.

Data processing Risk analysis Ship identification Traffic simulation

2015061330

Use of fuzzy risk assessment in FMEA of offshore engineering systems. Ocean Engineering, v 95, 1 February 2015, pp 195-204 http://www.sciencedirect.com/science/article/pii/S0029801814004508 Yang, Z., Wang, J. English

This paper proposes a novel framework for analysing and synthesising engineering system risks on the basis of a generic Fuzzy Evidential Reasoning (FER) approach. The approach is developed to simplify the inference process and overcome the problems of traditional fuzzy rule based methods in risk analysis and decision making. The framework, together with the FER approach has been applied to model the safety of an offshore engineering system. The benchmarking between the new model and a well-established Rule based Inference Methodology using the Evidential Reasoning is conducted to demonstrate its reliability and unique characteristics. It will facilitate subjective risk assessment in different

489 ABSTRACTS

engineering systems where historical failure data is not available in their safety practice.

Fuzzy systems Offshore engineering Risk analysis Safety

2.8 ENVIRONMENTAL PROTECTION

2015061331

Preliminary numerical study on oil spilling from a DHT. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume I, p 610 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Yang, H., Lu, J., Yan, S. English

This paper reports a preliminary 3D numerical study of submerged oil spilling from a damaged Double Hull Tanker (DHT) using a VOF based multiphase flow solver within the framework of the open-source CFD package OpenFOAM. In order to reflect the different features of two typical oil spilling scenarios, i.e. grounding and collision, two cases with spilling holes being located on the bottom and side wall of the DHT, respectively, are simulated. The numerical results are compared with the experimental data. Satisfactory agreements are achieved. The hydrodynamic features, particularly the role of the viscosity and turbulence effects, are discussed.

Computational fluid dynamics Double hulls Oil spills Tankers

2015061332

Modelling and control design of spilled oil tracking autonomous buoy. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume I, p 632 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Rathour, S.S., Akamatsu, T., Et al English

The paper describes design, development and control of Autonomous tracking of spilled oil on the sea surface and transmission of useful data to a land station in real time by floating buoy robot called Spill Oil Tracking Autonomous Buoy. Frequent occurrence of major oil spills in recent years and its consequences on the environment have caught the attention of public and media. This has created a global awareness of the risks of oil spills and the damage they cause to the environment. To prevent oil spills from spreading and causing further damage over wider areas and over time, the spilled oil must be recovered while it is still drifting on the sea surface. For effective and efficient recovery of oil spills, meteorological and oceanographic data around the oil slick is of prime importance. Under the domain of the above requirements the new design of SOTAB-II has been delineated in this paper which shows good response over its predecessor. To achieve the above mentioned targets a detailed dynamic Simulink model including SOTAB-II manoeuvring model, oil slick spread and drift model and oil sensor oil detecting model has been implemented. PID controller is implemented for controlling the size of the sail. The directional drifting of SOTAB-II is controlled using the oil sensor.

Buoys Monitoring Oil spills Spill tracking

2015061333

Current status and trends of the environmental performance in European ports. Environmental Science & Policy, v 48, April 2015, pp 57-66 http://www.sciencedirect.com/science/article/pii/S1462901114002329 Puig, M., Woodridge, C., Et al English

This paper investigates the current status and trends

ABSTRACTS 490

over time in the environmental performance of European ports. The research is based on the provision of data from 79 European ports on issues related to their environmental management, environmental priorities and current environmental monitoring practices. This study updates previous environmental reviews, so that the trends over time are drawn. For instance, 90% of respondent ports stated that they have an environmental policy and 94% of ports have designated environmental personnel. The percentage of ports that have an Environmental Management System has increased by +33% in the last 9 years. Air quality, port waste and energy consumption emerged as the three major environmental priorities of the European port sector in 2013. The research also reveals the diversity amongst European ports in terms of size and physical surroundings. Some examples are presented on specific initiatives carried out by sector organisations about the Top-10 port priority issues. The future expectations of European ports on data collection and reporting are described.

Environmental protection Monitoring Port management

2.9 GENERAL OPERATION

2015061334

Energy efficiency management system application and measured data analysis on container ship. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Yun, K., Kim, J., Et al English

Most of shipping companies are currently trying to ascertain their energy efficiency levels and to find energy saving opportunities to survive in this global recession. For this reason, the ship energy management system is considered as a monitoring and evaluation tool for cost reduction simultaneously satisfying SEEMP regulation. However, accurate vessel performance evaluation is very difficult in actual seagoing conditions. Vessel efficiency changes up to 30% depending on the weather condition, ship motion, engine status, etc. In this paper, the complicated co-relation affecting the ship performance is analysed to evaluate the true ship performance more accurately by normalizing and filtering to the calm sea condition based on the 150

measured data; the data was collected from the HJS container vessel equipped with the vessel energy management system. In addition, the in-depth effect analysis of the external environment, voyage operation, and main equipment status is executed proposing the potential energy saving percentage with statistical data analysis inside the newly developed energy management system by SHI.

Containerships Efficiency Ship performance

2015061335

Evaluating weather routing decisions using ensemble weather forecasts. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Skoglund, L., Kuttenkeuler, J., Rosén, A. English

This paper investigates the potential to reduce the risk of arriving later than the planned ETA by using ensemble weather forecasts as a compliment to the standard deterministic forecaster for the evaluation of the predicted performance of a route. Focus is on comparing the prediction errors of the performance and feasibility, resulting from using the deterministic and ensemble weather forecasts for performance predictions. Prediction errors are determined by using an approximation of the true evolution of the weather to calculate the realized performance and feasibility of candidate routes. To perform this investigation the performance predictions are calculated by simulating the performance of a panamax container carrier. The results of the investigation performed in this paper show that there are situations where the use of ensemble weather forecasts as an alternative, or compliment to the deterministic weather forecast can significantly increase the reliability of the routing decision. The increased reliability could help operation managers to maximize the utility of the vessel.

Weather forecasting Weather routing

491 ABSTRACTS

2015061336

Minimize fuel consumption using trim the ships loading computer and alarm monitoring system. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Bos, A.J., Michel, R. English

Minimizing fuel consumption is a major focus in the shipping industry, the laws and regulations on this subject are continuously tightened resulting in new innovative ideas. The International Maritime Organization by means of At MEPC 62 (July 2011) stated the Energy Efficiency Design Index (EEDI) mandatory for new ships. The Ship Energy Efficiency Management Plan (SEEMP) was made mandatory for all ships. A study has been started to use the ships systems to optimise the loading condition of the ships to reduce fuel consumption or improve the ships speed. The systems amongst others are the loading instrument and tank and draft measurement systems. Algorithms based on management science techniques and in particular operations research techniques result in promising results for optimisation of speed and fuel consumption. The influences of ship motions and nonlinearities on the resistance curve of the ship are taken into account.

Fuel consumption Loading calculators Trim Warning systems

2015061337

Promises, promises – critical assessment of measures to improve energy efficiency in containerships. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Bertram, V. English

Containership operators are confronted with a multitude of proposals for fuel saving measures and even more promises. Actual savings are generally much lower than quoted numbers in advertisement material and even scientific publications. Reasons for discrepancies are discussed and some guidelines for selecting suitable measures are given. There are gold mines to be exploited (technical and operational options with significant fuel savings without decrease

in performance) and mine fields to be avoided (false promises that result in zero savings or even losses). For a 4500 TEU containership, a case study illustrates realistic saving potential for refitting an existing ship and a newly designed, highly energy efficient ship. The case study shows that while significant improvements for existing ships are possible, the energy efficiency of new vessels is out of reach.

Containerships Efficiency Fuel conservation

2015061338

Proposing a common platform of shipping cost analysis of the Northern Sea Route and the Suez Canal Route. Maritime Economics and Logistics, v 17 n 1, March 2015, pp 9-31 http://www.palgrave-journals.com/mel/journal/v17/n1/abs/mel201429a.html Furuichi, M., Otsuka, N. English

Maritime trade between East Asia and Northwest Europe using the Northern Sea Route (NSR) has been recently increasing, because ship operators may take advantage of the shorter sailing distance of NSR whose navigable season has become longer because of retreating Arctic sea ice. As Arctic sea ice continues to retreat because of global warming, the NSR is now approximately 40 per cent shorter than the Suez Canal Route (SCR) for such trade. In 2013, shipping on the NSR marked a record 10 year-high volume of 1.36 million tons with 71 voyages. Accordingly, comparative analyses of estimated shipping cost via the NSR and the alternative conventional routes, especially the SCR, have been carried out. Furthermore, NSR/SCR-combined shipping, that is, when a vessel transits the NSR during the warmer months and the SCR in the colder months, has already been proposed as a realistic scenario for Arctic shipping in the previous studies. Since assumptions used in the cost estimations vary among the studies, as discussed by Lasserre, there remain some difficulties when comparing estimated shipping costs. This study aims at establishing a common platform of a wide range of cost estimation assumptions, through clarifying and analysing the cost components contained in the current literature. In addition, interviews with NSR shipping professionals were conducted concerning the NSR fee on an unofficial basis, since typically such fees are determined based on negotiations between ice breaker

ABSTRACTS 492

escort service provider and shipping company. An empirical analysis revealed that NSR/SCR-combined shipping of container cargo between East Asia and Northwest Europe can be commercially feasible.

Arctic regions Cost analysis Routes Suez Canal Transportation costs

2015061339

Application of ensemble neural networks to prediction of towboat shaft power. Journal of Marine Science and Technology, v 20 n 1, March 2015, pp 64-80 http://link.springer.com/article/10.1007/s00773-014-0273-2 Radonjic, A., Vukadinovic, K. English

In this paper towboat shaft power was predicted using various artificial neural networks. This work is a step toward reducing errors in the prediction of towboat power as well as providing better understanding of powering characteristics by the crew of the towboat. An ensemble neural network (ENN) and the single neural network (ANN) with two hidden layers are proposed to predict towboat shaft power. These two models were compared on the basis of their calculated root mean squared errors, mean absolute errors and relative errors. The database used for training and testing of the proposed ANN and ENN has been collected from the full-scale speed-power trials. Trials are conducted on selected towboats and convoys of barges. The goal of the paper is to show that ENN can be applied on towboat shaft power prediction and can improve the accuracy of the results over the single ANN. Computational results from this numerical example show that ENN definitely outperforms single ANN with two hidden layers. The contribution of this paper is a proposal to use an AIC-based ENN method for predicting towboat shaft powers. The paper is the first one that addresses AIC-based ENN method to predict towboat shaft powers.

Full scale tests Neural networks Power prediction Shafts Tugs

2015061340

Global view on ship trim optimisation. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper III-9, p 223 [12 p, 15 ref, 1 tab, 9 fig] http://www.int-nam.yildiz.edu.tr/2014/ Kishev, R., Georgiev, A., Et al English

The IMO requirements for reduction of GHG emissions from shipping, issued recently, reinforced the attempts to increase the energy efficiency of ships. One of the measures prescribed by IMO is Ship Energy Efficiency Management Plan (SEEMP). This, among other things, involves trim optimisation. The main objective function of the optimisation is the hydrodynamic performance (resistance, propulsion, sea-keeping and manoeuvring). However, there are many other issues, which have to be taken into account as constraints to optimisation, to mention a few: feasibility of ballasting (draft/trim) for specific loading conditions; bending moments and shear forces and stability for each specific loading condition; restrictions of bow draft for avoiding slamming; propeller immersion to avoid ventilation; bridge visibility. The paper is trying to identify and summarize the constraints of the above type that will limit the range of search of hydrodynamic energy efficiency optimisation.

Optimisation Ship performance Trim

2015061341

Verification of full-scale performance of eco-friendly bulk carriers under actual operating conditions by onboard performance monitoring. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 78, p 755 [9 p, 6 ref, 3 tab, 18 fig] http://www.crcpress.com/product/isbn/9781138027275 Orihara, H., Yoshida, H., Et al English

In this paper, full-scale performance of energy-efficient eco-friendly bulk carriers recently developed by Japan Marine United Corporation (JMU) is thoroughly verified by means of detailed onboard

493 ABSTRACTS

performance monitoring. Effectiveness of energy saving technologies for enhancing energy efficiency is evaluated under actual operating conditions. Onboard performance monitoring has conducted on a group of eco-friendly large-sized bulk carriers. Monitored performance data are analysed for both laden and ballast conditions together with monitored weather data for a wide variety of weather conditions. Analysed data are compared with performance predictions based on theoretical calculations and model experiments to assess the prediction accuracy. Comparisons show that hydrodynamic performance in terms of speed and power of JMU’s eco-friendly bulk carriers predicted at their design stage is well realized on full-scale ships over a wide range of actual operating conditions. Fuel savings capability of onboard voyage optimisation system “Sea-Navi” is also evaluated by the long-term trial navigation. It has shown that about 3% fuel saving is achieved relative to normal navigation without voyage optimisation by means of “Sea-Navi” voyage optimisation capability.

Bulk carriers Ship performance monitoring

2015061342

Increasing the operation window for dynamic positioned vessels using the concept of hybrid control. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1A: Offshore Technology, Paper No. OMAE2014-23601 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911385 Brodtkorb, A.H., Sørensen, A.J., Teel, A.R. English

In order to extend the operational window of marine vessels, the high-level control of the dynamic positioning (DP) system is revised. Major contributions of this paper include the modelling of a hybrid controller for a DP vessel in a varying sea state using a hybrid dynamical system framework proposed, and establishing global asymptotic stability of the closed-loop hybrid system. Simulations in a sea state varying from calm to extreme are conducted with the hybrid controller, and a single controller with

adaptive wave filtering for comparison. The single controller becomes unstable in extreme seas whereas the hybrid controller shows good performance. Switching is based on spectral analysis of the vessel wave frequency motions.

Control Dynamic positioning Ship operation

2015061343

Towards probabilistic models for the prediction of a ship performance in dynamic ice. Cold Regions Science and Technology, v 112, April 2015, pp 14-28 http://www.sciencedirect.com/science/article/pii/S0165232X14002262 Montewka, J., Goerlandt, F., Et al English

This paper introduces two probabilistic, data-driven models that predict a ship's speed and the situations where a ship is likely to get stuck in ice based on the joint effect of ice features such as the thickness and concentration of level ice, ice ridges, rafted ice, moreover ice compression is considered. To develop the models, two full-scale datasets were utilized. First, the dataset about the performance of a selected ship in ice is acquired from the automatic identification system. Second, the dataset containing numerical description of the ice field is obtained from a numerical ice model HELMI, developed in the Finnish Meteorological Institute. The collected datasets describe a single and unassisted trip of an ice-strengthened bulk carrier between two Finnish ports in the presence of challenging ice conditions, which varied in time and space. The relations between ship performance and the ice conditions were established using Bayesian networks and selected learning algorithms. The obtained results show good prediction power of the models. This means, on average 80% for predicting the ship's speed within specified bins, and above 90% for predicting cases where a ship may get stuck in ice.

Ice operations Ice transiting vessels Probabilistic methods Ship performance

ABSTRACTS 494

2015061344

Voyage optimisation supersedes traditional weather routing. Tanker Operator, v 14 n 4, March 2015, p 28 [2 p, 2 fig] http://www.tankeroperator.com/AllMagazine.aspx No author given English

A study (MEPC58/INF.21) by the IMO indicated that while weather routing can achieve a 2-4% reduction in fuel consumption and associated greenhouse gas emissions, even greater improvements can be achieved through technical and operational measures, such as speed and route management and fleet deployment planning. A Vessel and Voyage Optimisation Solution (VVOS) has been launched to deliver a return on investment that is claimed to exceed traditional weather routing methods. This article discusses the effects of key issues in voyage optimisation.

Optimisation Passage planning Voyage estimating

2015061345

Influence of occurrence probability of higher wave heights on long-term prediction of ship responses. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume III, p 425 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Miyake, S., Minoura, M. English

The difference of the frequency count of higher wave height in each scattering table strongly affects long-term prediction results. When a ship encounters a severe wave condition, ship speed decreases. When the wave condition becomes more severe, the captain judges an appropriate deceleration and change of the course to avoid danger of damage of the ship and crew. A long-term prediction method that has modelled the ship handling is necessary to obtain a realistic prediction value. In this paper, the characteristics of higher wave heights for variety of

scattering tables are investigated. Additionally, this paper proposes a long-term prediction method that models a situation when a ship is operated in such a way so as to avoid higher waves. Finally, this paper investigates the influence on a long-term prediction when the occurrence probability of a higher wave height is changed.

Predictions Probability Ship operation Ship response Wave height

2015061346

Performance of a ship powered by renewable energy. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4550-9. Volume 8A: Ocean Engineering, Paper No. OMAE2014-23368 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912041 Bøckmann, E., Steen, S., Myrhaug, D. English

A ship harnessing all its required energy from the wind, waves and sun is proposed. The ship employs five wing sails and two spring-loaded wave foils - one ahead of the bow and the other astern of the stern. In addition, the deck is covered with solar panels, which generate electricity for use aboard the ship. The wind speed is calculated from wave scatter tables, by finding the wind component of the waves from the two-peaked Torsethaugen wave spectrum and assuming unlimited fetch and fully developed sea. Wing sail and wave foil forces are calculated using a dynamic stall model and implemented in a time-domain ship simulator. Statistical estimates of the ship speed are calculated for the route Ponta Delgada, Azores - Funchal, Madeira, round-trip, for all four seasons. The expected ship speeds are about 6 knots, and the standard deviations are about 5 knots.

Propulsive performance Ship performance Solar energy Wave energy Wind propulsion

495 ABSTRACTS

2015061347

Fast and smart data. The Naval Architect, March 2015, p 39 [3 p, 2 tab, 3 fig] http://www.rina.org.uk/tna.html Dausendschön, K. English

This article explains how combining AIS data with various data sources can create new business intelligence. This helps to determine the cause of vessel delays, ports with shorter anchorage times for best retrofit solutions.

Data Ship identification Transponders

2015061348

Development of an approach towards mission-based design of Arctic maritime transport systems. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4538-7. Volume 10: Polar and Arctic Science and Technology, Paper No. OMAE2014-23848 [8 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912278 Bergström, M., Ehlers, S., Et al English

This paper describes an approach that utilizes a discrete event simulation tool and ice data from a numerical ice prediction model to enable mission-based design of arctic maritime transport systems consisting of a single or multiple arctic cargo ships. For a specific vessel design and route, the developed approach makes it possible to simulate how the transit time varies over time due to both varying ice conditions and stochastic factors such as the weather. Thus, for a given transport scenario (route, transport demand, and period of time), the approach can be used to determine a suitable vessel capacity, propulsion power, and ice class. When necessary, the approach can be used to analyse and design more complex transport system consisting of multiple vessels and routes. A case study is carried out to demonstrate how the approach could be applied in practice. The outcome of the case study indicates that the approach generates realistic figures, and that it is

flexible enough to make it possible to vary the number of included parameters and variables as needed.

Arctic marine transportation Discrete systems Ice conditions

2015061349

Efficiency of ice management for Arctic offshore operations. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4538-7. Volume 10: Polar and Arctic Science and Technology, Paper No. OMAE2014-24038 [8 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912290 Bakkay, B.E., Coche, E., Riska, K. English

The exploration and production of polar oil and gas fields, which are technologically challenging due to extreme weather conditions, are also constrained by strong environmental issues. Safe and economical activities in such hostile and fragile regions require very insightful engineering. The presence of sea ice is representing a triple challenge: economical, technological and environmental. This makes the Arctic exploration and production activities complex. Ice Management (IM) is one of the tools that could efficiently assist to develop Arctic reserves. However, for each project that uses IM operations, a preliminary study is required to evaluate the efficiency of these support operations and to estimate the possible extension in the season of operation of a field. Efficiency of an IM philosophy can be estimated in a global view based on the extension in the operability window. In a more detailed view, it can be assessed taking into account the optimal number of icebreakers, the IM patterns, the available time for eventual disconnection, and the floe size reduction (leading to ice load reduction). This study focuses on the ice floe size and loads reduction. The most common approach for physical management of sea ice is the one where icebreakers reduce floe size of the drifting ice upstream the floating platform. This paper describes this philosophy and demonstrates based on real-time simulation that its benefit is

ABSTRACTS 496

limited to mild ice scenarios such as unidirectional ice drift. A more efficient way to manage sea ice is (1) to identify the most hazardous events (e.g. big ridges); (2) prioritize these events; and (3) deal with them starting by the most hazardous one.

Arctic regions Ice control Offshore engineering

2015061350

Simulation-based analysis of Arctic LNG transport capacity, cost and system integrity. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4538-7. Volume 10: Polar and Arctic Science and Technology, Paper No. OMAE2014-24043 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912291 Erikstad, S.O., Ehlers, S. English

This paper presents a design case for arctic LNG transport, where liquefied gas is shipped from the Kharasevey terminal in Northern Russia to markets in US and Europe. Based on a fleet simulation model, the trade-off between the two main performance issues related to arctic transport are investigated; namely how to maintain transport system integrity in the harsh ice conditions, while maximizing the capacity utilization in a situation with considerable seasonal variations. The fixed contract, single destination base case shows that meeting the requirements for a robust solution implies a low degree of utilization in the summer season. To improve upon this situation, several mitigating strategies are evaluated, including vessel speed and size changes, fixed and seasonally varying contract and market mix schedules, revision stop rescheduling, storage capacity extensions and backhauling. The results indicate a high payoff from renegotiating the initial fixed schedule contract to allow for a higher degree of seasonal variations in the LNG deliveries. Further, increased storage capacity in loading port,

combined with winter revision stops will have a significant impact on both fleet utilization and total system integrity. Flexible contracts that imply seasonal deliveries to the UK will help ensure continuous production and deliveries in the winter season. Finally, surplus capacity gives opportunities for seasonal spot cargoes that could be exploited to increase fleet utilization rate.

Arctic regions LNG transportation Simulation

3.1 GENERAL HYDRODYNAMICS, HYDRAULICS AND OCEANOGRAPHY

2015061351

Wind and wave climate over the Black Sea. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 139, p 1309 [7 p, 14 ref, 5 tab, 12 fig] http://www.crcpress.com/product/isbn/9781138027275 Cherneva, Z., Guedes Soares, C., Andreeva, N. English

The work presents a statistical analysis of wind fields calculated by a regional atmospheric model (REMO) for period of 41 years. These wind fields have been used to force the WAM model to hindcast the waves for the same time interval producing a wave database that is also used for statistical purposes here. Results are shown at five representative points of the North-Western; South-Western; Central; North-Eastern and South-Eastern parts of the Black Sea. The main wind and wave climatic elements are presented. The results are compared with already published work.

Black Sea Statistical analysis Wave climate Wind

497 ABSTRACTS

2015061352

Fast integral methods for fully nonlinear water wave modelling. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume III, p 583 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Harris, J.C., Dombre, E., Et al English

This paper presents the development and validation of an efficient numerical wave tank (NWT), which solves for fully nonlinear potential flow in three dimensions. This boundary element approach is based on a variation of the wave model of Grilli et al., which has been well validated. The mixed Eulerian-Lagrangian time updating is based on a second-order Taylor series expansion. In order to solve problems with complex geometries, the model is reformulated to use a 3D unstructured triangular mesh of the boundaries, and apply the fast multipole method implementation, ExaFMM, in parallel, to make the use of large grids practical. The various issues related to performance are demonstrated, comparing against the existing higher-order boundary element NWT on a structured mesh, as well as demonstrating the capabilities of this modified approach.

Integral equations Numerical models Water waves Wave models

2015061353

Recent progress in CFD for naval architecture and ocean engineering. Journal of Hydrodynamics, Series B, v 27 n 1, February 2015, pp 1-23 http://www.sciencedirect.com/science/article/pii/S1001605815604528 Stern, F., Wang, Z., Et al English

An overview is provided of CFDShip-Iowa modelling, numerical methods and high performance computing (HPC), including both current V4.5 and V5.5 and next generation V6. Examples for naval architecture highlight capability and needs. High fidelity V6 simulations for ocean engineering and fundamental physics describe increased resolution for

analysis of physics of fluids. Uncertainty quantification research is overviewed as the first step towards development stochastic optimisation.

Computational fluid dynamics Naval architecture Ocean engineering

3.2 RESISTANCE AND PROPULSIVE PERFORMANCE

2015061354

Investigation of the radial bearing force developed during actual ship operations. Part 1: Straight ahead sailing and turning manoeuvres. Ocean Engineering, v 94, 15 January 2015, pp 67-87 http://www.sciencedirect.com/science/article/pii/S0029801814004442 Ortolani, F., Mauro, S., Dubbioso, G. English

The quantification of the radial force exerted by the propeller is of paramount importance for the improvement of the design procedures as well as for enhancing the prediction of the controllability and manoeuvring qualities of oceangoing vessels. In this work the radial load experienced by the bearing strut of a twin screw configuration is experimentally investigated by free running model tests. To this purpose the model has been equipped with a novel, in-house developed, two-component transducer. Results obtained for the straight ahead motion for a large range of speeds (0.5<FN<0.425) and turning circle manoeuvres at different rudder angles (15°–35°) and three different speeds (FN=0.218, 0.32 and 0.35) are presented and discussed in this paper. The main task is also to identify, from a phenomenological perspective, the nature of this load, in particular during tight manoeuvres, characterized by critical overloading of the propellers. The use of the free running, self-propelled model, is the best way to gain a deeper insight on the loads generated by the propeller during quasi-steady and, especially, transient motions that are difficult to reproduce in a towing tank via captive model tests.

Forces Manoeuvring Model tests Propeller efficiency Radial flow

ABSTRACTS 498

2015061355

Numerical investigation of a stepped planing hull in calm water. Ocean Engineering, v 94, 15 January 2015, pp 103-110 http://www.sciencedirect.com/science/article/pii/S002980181400434X Lotfi, P., Ashrafizaadeh, M., Esfahan, R.K. English

Stepped planing hulls enable the feasibility of running at relatively low Drag-Lift ratio by means of achieving more optimal trim angle at high speeds. Currently, there is no precise method to analyse these hulls over the full range of operating speeds. In this study, a three-dimensional computational fluid dynamics (CFD) model using volume of fluid (VOF) approach is presented for examining the characteristics of a planing hull having one transverse step. A procedure is presented to transform a series of fixed-position simulations into a free to heave and pitch simulation. Resistance, lift, running draft, dynamic trim angle, and wetted area are compared with available experimental data and those of a semi-empirical method at volumetric Froude number in the range of 2.41–7.12. Centreline wake profile and reattachment location are compared with those of empirical equations. Wetted area at forebody chines-dry mode is qualitatively compared with a typical under water photograph of a stepped hull. The quantitative and qualitative results are found in acceptable correlation with experimental data, hence they can be reliably used in the stepped hull hydrodynamic investigation.

Calm seas Computational fluid dynamics Planing hulls Ship hydrodynamics

2015061356

A verification of the ITTC/ISO speed/power trials analysis. Journal of Marine Science and Technology, v 20 n 1, March 2015, p 2 [12 p, 16 ref, 6 tab, 7 fig] http://link.springer.com/article/10.1007/s00773-015-0304-7 Strasser, G., Takagi, K., Et al English

Speed and power (S/P) trials are most important to guarantee the ship’s propulsive performance. However, it was pointed out that the existing procedures often give a good guideline, but are not specific and can introduce inconsistent results.

Recently, ITTC and ISO have improved their S/P trials procedures and harmonized the two procedures. During the harmonization process, the authors have verified the Mean of Means (MoM) method and the Iterative method which are used as the current correction methods and the Direct Power Method and the Extended Power Method which are applied for the evaluation of the acquired data. The results of verification are presented in this paper. The results show that using the MoM method for each power setting, two double runs should be made to keep the accuracy of S/P trials, and the Iterative method leads to less errors in average of the tested cases when 1 + 2 + 2 double runs are used in the MoM method, although the methods are equally adequate if the time periods between the runs are short enough. In specific cases, e.g. in case of large speed range and/or humps and hollows within the speed–power curve, the MoM method has advantages over the Iterative method. In case of current time history deviating from the assumed parabolic/sinusoidal trend and the change of the current within the time span of two double runs is very high; neither of the methods is applicable. Summarizing the results, the Iterative method is fully compatible with the simple Direct Power Method.

Procedures Propulsive performance Sea trials

2015061357

On the enhancement of coupling potential flow models to RANS solvers for the prediction of propeller effective wakes. Journal of Marine Science and Technology, v 20 n 1, March 2015, pp 104-117 http://link.springer.com/article/10.1007/s00773-014-0255-4 Sánchez-aja, A., Martio, J., Et al English

The calculation of the effective wake within the CFD context is usually made by combining a potential-flow method for modelling the propeller forces with a RANS equation solver for simulating the viscous flow around the hull and possible appendages. The different assumptions and/or simplifications made in the potential flow model relative to the viscous flow solver may result in significant errors in the prediction of the effective wake particularly for high loadings. This is especially troublesome for ships with full forms where large differences are expected between the nominal and effective wake, and for special propulsion applications such as contra-rotating units. Such errors are responsible within the

499 ABSTRACTS

hydrodynamic design problem for an unadjusted prediction of the propeller pitch, and within the hydrodynamic analysis problem for a deficient prediction of self-propulsion point. This paper presents an approach based on correction factors which converts propeller-induced velocities approximately estimated via potential flow theory into viscous induced velocities on the basis of a viscous flow RANS analysis. The correction factors are calculated for one reference advance number and work accurately in a neighboring region where the propeller loading may change about ±50 %. This procedure allows controlling one of the errors present in the calculation of effective wakes, namely the error derived from coupling a potential-flow method for the representation of the propeller with a RANS solver. Consequently, it permits calculating the effective wake more precisely. The approach is illustrated for a simple case in which the potential flow model representing the propeller is an actuator disk.

Computational fluid dynamics Contrarotating propellers Potential flow Propeller races

2015061358

Cartesian-grid-based computational analysis for added resistance in waves. Journal of Marine Science and Technology, v 20 n 1, March 2015, pp 155-179 http://link.springer.com/article/10.1007/s00773-014-0276-z Yang, K-K., Kim, Y., Nam, B-W. English

A Euler equation solver based on a Cartesian-grid and non-uniform staggered grid system is applied to simulate and analyse the ship motion and added resistance in waves. Water, air, and solid phases are distinguished using a volume fraction function for each phase and in each cell. To capture the water interface, the tangent of hyperbola for interface capturing scheme is used with a weighted line interface calculation method. The volume fraction of a solid body embedded in a Cartesian-grid system is calculated using a level-set algorithm, and the body boundary condition is imposed using a volume-weighted formula. Numerical simulations for a Wigley III hull and an S175 containership in regular waves are carried out to validate the newly developed code and to compare the effects of numerical methods for calculating the added resistance. All the results are compared with experimental data, and a calculation for the KRISO’s very large crude carrier 2 is also

performed. From the grid convergence test for incident wave generation and the added resistance calculation, the sensitivity of the grid spacing is investigated, and the minimum requirements for the number of gird points are suggested to reliably calculate the added resistance in waves.

Added resistance in waves Computational fluid dynamics Seakeeping

2015061359

The adaptive ship structure – using adaptive stern flaps to improve vessels’ efficiency under off-design operational conditions. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper III-3, p 159 [10 p, 6 ref, 3 tab, 6 fig] http://www.int-nam.yildiz.edu.tr/2014/ Krause, M., Roland, F., Et al English

The main idea of the adaptive ship structure comes from the collaborative project ADAM4EVE, which aims at exploring the potentials of adaptive and smart materials and structures in ships and pave the way for industrial application. The adaptive stern flap will allow ships to react more flexible to the changing operational and environmental conditions and thus will provide a more efficient and environmentally friendly operation for a sustainable future, while maintaining the same safety requirements from the classification societies. Hydrodynamic model tests have shown that a small change in the aft-hull geometry can have a significant influence on the ship’s dynamic trim and reduce the resistance at off-design operations. An actuated stern flap is proposed to achieve the change in the aft-hull geometry which requires only small shape adaptations of the aft-hull structure. The initial dimensions for the extended flap are defined by the available space in the aft section of the vessel and by hydrodynamic requirements based on viscous flow CFD analyses. The implementation of the stern flap structure is in accordance with Lloyd’s Register rules for RoPax ships. The stern flap can be, for example, actuated by bellows cylinders, which are commonly used as air suspension in road and rail transportation. Based on the current hydrodynamic test results, 2 to 3% of resistance reduction is expected at some off-design conditions. Assuming that the adaptive stern flap is installed on a RoPax ferry travelling regularly in North Minch of

ABSTRACTS 500

Scotland, the gaining (fuel saving in terms of money and emission reduction) will override the paying (increased costs and emissions during the production phase) for a stern flap installation from a long term ship life cycle perspective.

Flaps (control surfaces) Propulsive efficiency Ro/ro ships Stern location

2015061360

Computation of total resistance of ships and a submarine by a RANSE based CFD. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper V-4, p 383 [20 p, 32 ref, 4 tab, 20 fig] http://www.int-nam.yildiz.edu.tr/2014/ Sukas, Ö.F., Kinaci, Ö.K., Bal, S. English

The prediction of resistance of ships and submerged bodies is an important aspect in naval architecture. Total resistance of a floating body can be decomposed into viscous and wave resistance components. There are potential, viscous and experimental methods to determine the resistance components of a ship. RANSE (Reynolds Averaged Navier Stokes Equations) based CFD (Computational Fluid Dynamics) methods usually follow the experimental method that determines the form factor first. However, it is proven in recent studies that the form factor changes with the Reynolds number. As the Reynolds number increases; this change in the form factor is being neglected. In this study, a RANSE based prediction of total resistance (viscous + wave) is presented that overcomes this flaw. Single-phase and multi-phase analyses have been done in this study by using the interface capturing approach that solves the RANSE equations on a predetermined grid which covers the entire domain and Volume of Fluid (VOF) method to simulate the free surface flow for surface piercing (ships) and a fully submerged body. First, the Wigley hull has been used as a benchmark ship to obtain the total resistance and this benchmark has been employed to validate the numerical resistance test results. In addition, the proposed method for calculating the wave resistance and viscous resistance was implemented on a displacement ship and CFD results compared with those of towing tank tests performed in Ata Nutku Ship Model Testing Laboratory of Istanbul Technical

University. Lastly, effect of the appendages of a submarine on total resistance is investigated. Comparisons were made in terms of the frictional resistance with the naked body solutions. The results reveal the robustness of the present methodology.

Computational fluid dynamics Submarines Viscous resistance Wave resistance Wigley models

2015061361

Optimal geometry for 3D supercavitating hydrofoils. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper V-5, p 403 [17 p, 27 ref, 7 tab, 20 fig] http://www.int-nam.yildiz.edu.tr/2014/ Çelik, F., Bal, Ş., Özden, Y.A. English

In this study the optimal geometry of a supercavitating wing has been investigated. The wing optimisation has been performed so that the lift-to-drag ratio is maximum. Flow analysis for supercavitating or partially cavitating wings have been carried out with a BEM method based on the potential flow theory. It is aimed to optimise a rectangular supercavitating wing (NACA16006, AR=2, σ=0.2, α=4°) for the lift coefficient (CL) at the cavitation number (σ) where no cavitation is occurred and for the lift coefficient (CL) of the supercavitating wing. The optimal wing geometry has been searched by changing the angles of attack and/or the camber ratios of the wing sections by having a minimum deviation totally. The effects of elliptical circulation distribution have been examined. It is concluded that a change in two variables, the camber ratio and the angles of attack, by providing an elliptical circulation distribution increases the efficiency at most. The optimal wing geometry for the lift coefficient (CL) of the non-cavitating wing gives the maximum efficiency.

Boundary element method Circulation Optimisation Supercavitating hydrofoils Wings

501 ABSTRACTS

2015061362

Computational analysis of multiphase ship resistance including 6-DoF motion using OpenFOAM. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper V-6, p 421 [11 p, 12 ref, 1 tab, 3 fig] http://www.int-nam.yildiz.edu.tr/2014/ Ertinaz, F. English

With the increasing capability of computational resources in the past two decades, computational fluid dynamics (CFD) became a crucial tool for analysis in naval hydrodynamics. As a consequence, CFD can be used to tackle a complex application like multiphase ship resistance as well even though the cost of simulation is still considerable. In the scope of this project a transient multiphase solver is used to compute the ship resistance in turbulent incompressible flow including 6-DoF motion. The software of which this study is based is OpenFOAM, an Open Source object-oriented library for numerical simulations in continuum mechanics written in the C++ programming language (Jasak et al., 2007). This paper presents the algorithm details used by OpenFOAM in terms of its computational complexity and provides a comparison of the results for various discretization schemes, boundary conditions and turbulence models. OpenFOAM framework is selected as the basis library for code development because of its flexibility in the development of customized numerical solvers and absence of licensing costs.

Computational fluid dynamics Multiphase flow Resistance

2015061363

Development of a small nose to reduce added resistance due to short head waves for a blunt ship. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper V-8, p 443 [10 p, 2 ref, 1 tab, 20 fig] http://www.int-nam.yildiz.edu.tr/2014/ Ikeda, Y., Aoyama, Y., Et al English

Blunt ships like large tankers and bulkers decrease their speed in short severe head seas because of the added resistance due to the waves. In the present paper, it is theoretically and experimentally confirmed that high stagnation pressure acting on the blunt bow surface above calm water surface by waves hitting may cause large spray and the added resistance. To reduce the high stagnation pressure, small triangle NOSEs are developed on the basis of the calculated pressure distribution by CFD or the observed spray by experiments, and attached on the bow. The effects of the NOSE on reduction of the added resistance due to waves are investigated by model experiments and CFD.

Added resistance in waves Blunt bodies Pressure distribution

2015061364

CODLAW ship propulsion simulation: performance optimisation by smart control. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper VI-1, p 473 [10 p, 9 ref, 1 tab, 11 fig] http://www.int-nam.yildiz.edu.tr/2014/ Altosole, M., Figari, M., Piastra, F. English

The paper presents an integrated simulation study aimed at ship’s performance prediction, during both sailing and motor propulsion, for a Combined Diesel eLectric and Wind (CODLAW) propulsion plant installed on board of the tall ship Amerigo Vespucci. The ship has recently undergone a complete platform system revamping, and will be equipped with the most innovative integrated full electric propulsion plant, still preserving the rigs to honour the seafaring

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tradition. The study is focused on the behaviour of the new electric propulsion motor, driving the fixed pitch propeller, during sailing navigation condition, and in particular on the negative effect of the trailing propeller. A newly developed control system will drive the propeller to the “zero thrust” mode during sailing, for several wind conditions, in order to optimise the ship performance. Feasibility and benefits of this propulsion option are investigated through a motor – sailing propulsion simulator, developed in the MatLab-Simulink environment, and off-line CFD analysis carried out for the evaluation of the soft sails aerodynamics.

Computational fluid dynamics Diesel electric propulsion Propulsive performance Time domain Wind propulsion

2015061365

A method to realize full-scale equivalent propeller characteristics and speed using free-running model ship. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper VI-2, p 483 [12 p, 17 ref, 1 tab, 8 fig] http://www.int-nam.yildiz.edu.tr/2014/ Ueno, M., Tsukada, Y. English

The rudder effectiveness and speed correction (RSC) for the similarity of manoeuvring motion of free running model ships proposed by the authors controls the propeller rate of revolution and the auxiliary thrust depending on model ship speed. The solutions of two nonlinear simultaneous equations for RSC tell how to control these two parameters. If a ship course is straight and an environmental condition is symmetric about the ship centre plane, or other measures ensure the similarity of rudder effectiveness, one can discard one of these two equations, that for the rudder effectiveness similarity. This situation allows us to make one of propeller characteristics of a free-running model ship similar to full-scale since the equation to be solved is one only for the speed response similarity but the control parameters remain two. This paper clarifies how to control the propeller rate of revolution and the auxiliary thrust in such situations to ensure the similarity both of ship speed and one of propeller characteristics; propeller thrust, propeller torque,

propeller power, propeller slip ratio or propeller advance ratio, and hull advance ratio.

Free running models Model tests Propeller efficiency Ship speed Thrusters

2015061366

Comparison on hydrodynamic behaviour of shape-adaptive and rigid marine propellers. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper VI-3, p 495 [11 p, 7 ref, 5 tab, 8 fig] http://www.int-nam.yildiz.edu.tr/2014/ Bal, H., Görener, N. English

The paper focuses on the fluid-structure interaction (FSI) of shape-adaptive marine propellers. The aim is to develop a simulation procedure to predict the hydro-elastic behavior on performance of the propeller and to evaluate the effect on efficiency. Metal alloys, such as nickel-aluminum-bronze, manganese aluminum alloy are most the common materials used in the design and development of ship propellers. However, recent studies focus on a shape-adaptive propeller which allows the blades to deform with load changes such that the propeller performance is enhanced compared to a conventional “rigid” propeller. The goal of shape adaptability in this type of propeller is to reduce cavitation, noise and to gain higher efficiency over a greater range of operating conditions. In the scope of this paper, propeller geometry with different material properties is analysed using a Computational Fluid Dynamics (CFD) Method with ANSYS Fluent software. The analysis of shape-adaptive propeller is a multi-stage process. The hydrodynamic pressures which are acquired from CFD analysis are applied as external surface pressure loads in the structural analysis using the Finite Element Method (FEM) to obtain the deformed geometry. The deformed new geometry is exported to ANSYS Fluent and is analysed with the same boundary conditions using this geometry. At the end of this procedure, thrust and torque values are obtained and compared against the propeller which is assumed as non-deformed. In propeller design, as discussed by the International Maritime Organization (IMO) Energy Efficiency Design Index (EEDI), small gains in propeller efficiency can be significant

503 ABSTRACTS

improvement for the operation of a ship, considering the propeller’s operational life. The authors of this paper expect, as the outcome of this paper, to demonstrate an improved performance when shape-adaptive propeller is used, in terms of torque and thrust, over the conventional rigid propellers. This study requires a staged analysis approach in order to demonstrate the hydrodynamic and structural characteristics. This study will identify the efficiency and limits of both a shape-adaptive and a rigid propeller.

Computational fluid dynamics Finite element method Fluid structure interaction Propeller efficiency

2015061367

Numerical investigation of wake field effects on propeller performance for different ships. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper VI-4, p 507 [11 p, 12 ref, 6 tab, 9 fig] http://www.int-nam.yildiz.edu.tr/2014/ Ekinci, S., Çelik, F., Doğrul, A. English

Because the flow coming to the propeller behind the ship is not uniform, it can cause adverse effects like propeller borne vibration and noise. In this study, five different wake distributions for a sample propeller geometry behind the ship are investigated in order to observe propeller performance, thrust values in the propeller blade for one rotation, and pressure changes on the ship by propeller. In the calculations, a numerical method based on lifting surface theory is used. From the calculations, it can be seen that effect of skewness has a significant effect in the cases where the flow is far from uniformity. It is concluded that vibration and noise can be lowered in significant amounts by increasing the skewness of the propeller in these working conditions.

Lifting surface theory Propeller efficiency Propeller races

2015061368

Toward the optimum design propulsion device for a specific trawler. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 71, p 687 78 p, 20 ref, 3 tab, 3 fig] http://www.crcpress.com/product/isbn/9781138027275 Coache, S., Laurens, J.-M. English

Using an existing 42 meters trawler, the authors analysed the effects of various configurations to decrease the propeller load. The gain obtained on first analysis based on a systematic propeller series is already significant. Using potential flow and Navier-Stokes solvers, it is shown how the propeller design can be improved further. The design strategy consists in adjusting the distribution and geometry of the pitch and sections in order to avoid flow separation and cavitation even when the propeller is excessively loaded. The duct section and the propeller blade geometries are iteratively improved in order to obtain the optimal propulsive device. It is shown that for the example chosen in this study the overall improvement is significant enough to justify a retrofit. It also contributes to the argument that there is no universal solution and that each trawler or class of trawlers has to be studied individually.

Propeller efficiency Propeller loading Trawlers

2015061369

Experimental and numerical investigations for modelling propeller cavitation noise. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 72, p 695 [10 p, 19 ref, 6 tab, 21 fig] http://www.crcpress.com/product/isbn/9781138027275 Gaggero, S., Gaggero, T., Et al English

A major source of the underwater radiated noise from ships is represented by propulsion systems and by propellers in particular. The main noise-generating mechanism within ship propellers is cavitation, associated to the growing and collapse of vapour bubbles resulting from the unsteady hydrodynamic

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pressure field generated on the blades. The control of propeller underwater radiated noise is therefore strictly related to the control of cavitation phenomena, which are responsible for a larger part of the radiation. The activity within work package 2 of the collaborative project AQUO (Achieve QUiter Oceans by shipping noise footprint reduction, www.aquo.eu) of the 7th FP of the EU focuses on this aspect, which is analysed both from the experimental and numerical viewpoint. This paper reports motivations, aims and achievements of such activity in the first year of the project.

Cavitation noise Propeller cavitation Propeller efficiency

2015061370

Practical considerations for marine propeller sizing. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 74, p 717 [6 p, 7 ref, 2 tab, 6 fig] http://www.crcpress.com/product/isbn/9781138027275 Yehia, W., Moustafa, M.M. English

Propeller sizing is sometimes regarded as a black art, but like every other magic trick, it’s just a matter of standard methods and practice. Matching a propeller, gear and engine means that the equilibrium between the available engine torque and the required propeller torque will not overload the engine and that the thrust required to make speed is available throughout the range of operation. This paper is intended to cover the basic elements of marine propeller selection to get engine, gear and propeller matched to achieve the desired goals in terms of speed, possibly towline pull, thrust and engine loading. This paper presents a practical strategy for a successful propeller sizing with reference to drive train available power and rate of rotation. A computer program for propeller matching (PROMAT) has been developed in order to assure matching purpose. The general purpose of this study has been successfully applied to a typical case study of preliminary propeller sizing problems.

Propeller size Propulsive power

2015061371

Free surface flow simulation around a Wigley hull using viscous and potential flow approaches. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 103, p 985 [8 p, 24 ref, 2 tab, 9 fig] http://www.crcpress.com/product/isbn/9781138027275 Ahmed, Y.M., Ciortan, C., Et al English

The incompressible free surface flow around a Wigley hull form has been simulated using a commercial RANSE code using the two-phase Eulerian-Eulerian fluid approach, and a potential flow code using on the Rankine source method. The flow has been simulated around the hull at two Froude numbers and comparisons between the results and the experimental results have been made. Two turbulence models (k-ε and Shear Stress Transport) are used in the commercial RANSE code. The computational grid in the commercial code has been used for generating the unstructured tetrahedral and structured hexahedral computational grid required for the RANSE code solver. The potential flow code uses quadrilateral structured patches to mesh both the ship hull surface and the water surface around the hull. In all the simulations, the hull is fixed. The results compare well with the available experimental data.

Free surfaces Incompressible flow Mathematical models Wigley models

2015061372

Entrainment of air at the transoms of full-scale surface ships. Journal of Ship Research, v 59 n 1, March 2015, pp 49-65 http://www.ingentaconnect.com/content/sname/jsr/2015/00000059/00000001/art00004 Terrill, E. J. , Taylor, G. R. English

This article reports on the results from a series of full-scale trials designed to quantify the air entrainment at the stern of an underway vessel. While an extremely complex region to model air entrainment due to the confluence of the breaking transom wave, bubbles from the bow, turbulence from the hull boundary layer, and bubbles and turbulence from propellers, the region is a desirable area to characterize and

505 ABSTRACTS

understand because it serves as the initial conditions of a ship's far-field bubbly wake. Experiments were conducted in 2003 from R/V Revelle and 2004 from R/V Athena II using a custom-built conductivity probe vertical array that could be deployed at the blunt transom of a full-scale surface ship to measure the void fraction field. The system was designed to be rugged enough to withstand the full speed range of the vessels. From the raw time-series data, the entrainment of air at speeds ranging from 2.1 to 7.2 m/s is computed at various depths and beam locations. The data represent the first such in-situ measurements from a full-scale vessel and can be used to validate two-phase ship hydrodynamic CFD codes and initialize far-field, bubbly wake CFD models.

Air entrainment Bubbles

2015061373

Numerical solution for ship with forward speed based on transient green function method. Journal of Ship Mechanics, n 12, 2014, pp 1444-1452 http://www.cssrc.com/ Li, H., Ren, H-l., Et al Chinese

A 3-D time domain program based on transient Green function method was developed to analyse hydrodynamic problems involving ship moving at a constant forward speed. From the point of view of the numerical accuracy and calculation efficiency, the precise integration method and some mathematical derivations were employed to evaluate the memory part of the transient Green function and its derivatives. And numerical tests were carried out for a Wigley-hull-form ship; the obtained results are compared with experimental data and reference results. Through the comparisons on the hydrodynamic coefficients, the reliability of the 3-D time domain program is confirmed.

Forward speed Green function Hydrodynamic characteristics Ship hydrodynamics

2015061374

Statistical reliability analysis of numerical simulation for prediction of model-ship resistance. Journal of the Society of Naval Architects of Korea, v 51 n 4, August 2014, p 321 [7 p, 9 ref, 7 tab, 8 fig] http://www.snak.or.kr/eng/sub03_01.html Lee, S.B., Lee, Y.M. Korean

A wide scope of numerical simulations was performed to predict model-ship resistances by using STAR-CCM+ and OpenFOAM. The numerical results were compared with experimental measurements in a towing tank to analyse the statistical reliability of the present simulations. Based on the normal distribution of resistance errors in 113 cases of container carriers, tankers and very large crude-oil carriers, the confidence intervals of numerical error were estimated as [-2.64%,+2.32%] and [-1.82%, +1.87%] with 95% confidence in STAR-CCM+ and OpenFOAM, respectively. The resistance errors of liquefied natural gas carriers with single- and twin-skeg were confident in the ranges of [-2.51%, +2.64%] and [-2.29%, +1.46%], respectively. The grid uncertainty of resistance coefficients for KCS was also quantitatively analysed by using a grid verification procedure. The grid uncertainty of OpenFOAM (5.1%) was larger than 4.4% uncertainty of STAR-CCM+ although OpenFOAM provided statistically more confident results than those of STAR-CCM+. It means that a grid system verified under a specific condition does not automatically lead to statistical reliability in general cases.

Computational fluid dynamics Resistance Uncertainty

2015061375

Prediction of self-propulsion parameters for multi-propeller ships. Chinese Journal of Ship Research v 9 n 6, December 2014, p 59 [6 p, 13 ref, 8 tab, 12 fig] http://www.ship-research.com/EN/abstract/abstract1204.shtml Xi, P., Xiong, Y., Et al Chinese

In this paper, a four-propeller surface ship is studied and an integral mathematic model including the hull appendage and propellers is established. Using a RANS solver and moving grids， the self-propulsion factors are predicted by gradually modifying the rotation speed of the propeller and by respectively

ABSTRACTS 506

calculating the propeller features. The result shows that the self-propulsion factors of the inner propeller differ from those of the outer propeller. The wake fraction and thrust deduction fraction of the inner propeller is bigger than the outer propeller's. In brief, the differences among four-propeller ship self-propulsion factors can be observed and are seen to fit the ordinary relation of thrust deduction and wake, which validates the reliability of the new proposed method and provides the basis for future self-propulsion tests of multi-propeller ships.

Propellers Self propulsion Thrust deduction

2015061376

Interaction between warm model ice and a propeller. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4556-1. Volume 10: Polar and Arctic Science and Technology, Paper No. OMAE2014-23447 [11 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912268 Huisman, T.J., Bos, R.W., Et al English

Ships sailing in ice require a propeller that is able to endure both extreme loads and fatigue loads and operate efficiently in ice and open water. Knowledge and descriptions of the physical processes of propeller-ice interaction are essential to model the interaction with its dominant parameters and finally predict the loads. The research described in this paper uses an experimental setup to determine if the crushing strength of ice, or in general a solid, is a dominant parameter in propeller-ice interaction as stated in empirical and theoretical models. Warm model ice, a paraffin based material to be used at room temperature, with ex-situ tested crushing strength, density and elasticity, is supplied to an in-situ model propeller at different rpms. One blade of the propeller is equipped with a six-component load sensor. Impacts are recorded in the time domain and synchronised with high speed footage. The data is analysed to understand and explain the impact

behaviour by comparing it with rotational speed, load and footage. Scaling of the warm model ice properties is discussed as well due to density differences between warm model ice and sea ice.

Artificial ice Ice properties Propeller efficiency Propeller ice interaction

2015061377

Uncertainty analysis for added resistance experiment of KVLCC2 ship. Ocean Engineering, v 95, 1 February 2015, pp 143-156 http://www.sciencedirect.com/science/article/pii/S0029801814004648 Park, D-M., Lee, J., Kim, Y. English

This study considered the uncertainty analysis in the measurement of the motion response and added resistance of waves in seafaring conditions. Methods of uncertainty analysis for seakeeping experiments are not well established. Particularly, no previous studies have specifically investigated added resistance measurements in seafaring conditions. In this study, uncertainty analysis based on ITTC Recommended Procedures and Guidelines (2008a), adopted with the method used by the International Organization for Standardization (ISO, 1995), was conducted and the assessment results are summarized in tabular form. The ship model used in the experiment is KVLCC2 ship, which has a hull shape of a typical large tanker. Vertical motion and added resistance were measured at nine regular waves in head sea. For the validation of the measured data, the experimental results were compared with not only those obtained at other test facilities but also the computational results found via strip and Rankine panel methods. In three cases among the nine wave conditions, at least 15 repeated measurements were conducted for the uncertainty analysis of the heave, pitch, and added resistance quantities. In this paper, the sources of uncertainty in added resistance measurement are summarized, and their uncertainties are quantified. From the uncertainty analysis, the sensitivity to each uncertainty source was observed. This study will be

507 ABSTRACTS

useful in understanding the fundamental uncertainties associated with the towing tank measurement of motion responses and added resistance in waves.

Added resistance in waves Model tests Uncertainty

2015061378

Power-saving device for air bubble generation using a hydrofoil to reduce ship drag: Theory, experiments, and application to ships. Ocean Engineering, v 95, 1 February 2015, pp 183-194 http://www.sciencedirect.com/science/article/pii/S0029801814004314 Kumagai, I., Takahashi, Y., Murai, Y. English

The authors have developed a new power-saving device to reduce the drag of a ship’s hull using small bubbles. The device reduces the energy required for bubble generation. The device, which consists of angled hydrofoils with air introducers, uses the low-pressure region produced above the hydrofoil as the ship moves forward to drive atmospheric air into the water. The article describes the device principles obtained from simple fluid dynamic theory and, through experiments performed in a small towing tank, show the fundamental air entrainment and bubble generation processes for the flow behaviour around a hydrofoil beneath a free surface. The authors also present a semi-empirical scaling process for practical application to full-size ships to estimate the net drag reduction achieved by this device. Finally, the results of a series of full-scale tests are reported and show that, with correct operation, our device can produce a net power saving of 5–15% for ships.

Bubbles Energy conservation Drag reduction Hydrofoils Multiphase flow

2015061379

Thruster-interaction effects on a DP shuttle tanker – wake flow measurements of the main propeller and bow tunnel thrusters. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4538-7. Volume 1B: Offshore Technology, Paper No. OMAE2014-24028 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911407 Cozijn, J.L., Hallmann, R. English

This paper discusses thruster interaction effects for a DP shuttle tanker, equipped with two main propellers and rudders, as well as two bow tunnel thrusters. Thruster-interaction model tests were carried out and detailed PIV measurements were taken of the wake flow behind the main propellers and rudders. Furthermore, PIV measurements were taken of the wake flow of one of the two bow tunnel thrusters. The flow velocities were measured in a large number of cross sections at different down-stream positions. The PIV measurements provide a detailed image of the velocities in the thruster wake, showing axial velocities, as well as transverse and vertical velocity components. The results of the first set of measurements showed in detail the wake flow behind the main propeller of the DP shuttle tanker. The wake flow pattern was determined at rudder angles of 0 deg and 10 deg. Since the research is related to DP performance, bollard pull conditions (zero forward speed) were considered in the model tests. The results of the second set of measurements showed in detail the wake flow of one of the bow tunnel thrusters. The wake flow pattern was investigated in zero speed conditions, as well as for the vessel at forward speed. The observed flow patterns helped to explain the reduced bow tunnel performance at forward speed. The results of the present research are used to further improve the understanding of the physics of thruster interaction effects. Furthermore, the results will serve as validation material for CFD calculations that are currently being performed.

Dynamic positioning Flow measurement Interactions Propellers Thrusters

ABSTRACTS 508

3.3 MOTION, SEAKEEPING AND MANOEUVRING

2015061380

Robust fin control for ship roll stabilization based on L2-gain design. Ocean Engineering, v 94, 15 January 2015, pp 126-131 http://www.sciencedirect.com/science/article/pii/S0029801814004223 Hinostroza, M.A., Luo, W., Guedes Soares, C. English

A robust fin controller based on L2 gain design is proposed, in order to reduce the roll motion of surface ships. The plant consists of the ship roll dynamics and that of the fin actuator. The uncertainties including the modelling errors and the environmental disturbances induced by waves are considered in the cascaded roll system. A state feedback control is adopted to compensate the modelling errors and the derivative of desired fin angle. The disturbance is suppressed by L2 gain design. The Lyapunov function is employed in the controller design, which guarantees the stability of the fin stabilizer. Simulation results are reported and the superior performance of the fin controller with L2-gain design is illustrated when compared to a PD controller.

Fin stabilizers Roll stabilizers Ship motions

2015061381

Introduction of MMG standard method for ship maneuvering predictions. Journal of Marine Science and Technology, v 20 n 1, March 2015, pp 37-52 http://link.springer.com/article/10.1007/s00773-014-0293-y Yasukawa, H., Yoshimura,Y. English

Many simulation methods based on the Manoeuvring Modelling Group (MMG) model for ship manoeuvring have been presented. Many simulation methods sometimes harm the adaptability of hydrodynamic force data for the manoeuvring simulations since one method may be not applicable to other method in general. To avoid this, a basic part of the method should be common. Under such a background, a research committee on the standardization of a mathematical model for ship maneuvering predictions was organized by the Japan

Society of Naval Architects and Ocean Engineers and a prototype maneuvering prediction method for ships was proposed, the so called MMG standard method. In this article, the MMG standard method is introduced. The MMG standard method is composed of 4 elements; manoeuvring simulation model, procedure of the required captive model tests to capture the hydrodynamic force characteristics, analysis method for determining the hydrodynamic force coefficients for manoeuvring simulations, and prediction method for manoeuvring motions of a ship in full scale. The KVLCC2 tanker is selected as a sample ship and the captive mode test results are presented with a process of the data analysis. Using the hydrodynamic force coefficients presented, manoeuvring simulations are carried out for KVLCC2 model and the full scale ship for validation of the method. The present method can roughly capture the manoeuvring motions and is useful for the manoeuvring predictions in full scale.

Manoeuvring Mathematical models Predictions Standards

2015061382

Sensitivity of thrust efficiency loss in dynamic positioning predictions. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper II-1, p 81 [10 p, 15 ref, 1 tab, 7 fig] http://www.int-nam.yildiz.edu.tr/2014/ Nabergoj, R., Prpić-Oršić, J., Valčić, M. English

Existing strategies and proposed methods for optimal thrust allocation in dynamic positioning systems of floating objects are primarily focused on minimization of power consumption and treating numerous limitations and conditions that should be satisfied at the same time. On the other hand, it can be observed that thruster interaction effects such as axial and transverse current, thruster-hull interaction, thruster-thruster interaction and ventilation are rarely taken into account. These effects, whether they occur separately or in combination, can cause significant thrust losses, which consequently degrade the reliability of dynamic positioning systems, decrease accuracy, increase response time and power/fuel consumption, etc. The main goal of this paper is the quantification of the effects due to different allocation

509 ABSTRACTS

methods on the resulting DP capability predictions of the vessel. Application to an existing offshore vessel has been considered to highlight their sensitivity on the final result in terms of operational rosettes.

Dynamic positioning Interactions Thrust Thrusters

2015061383

A development of high lift performance rudders with wedge tail and end plate using CFD. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper V-1, p 347 [12 p, 3 ref, 4 tab, 12 fig] http://www.int-nam.yildiz.edu.tr/2014/ Nguyen, T. van, Ikeda, Y. English

In this study, a high lift rudder with a wedge tail and an end plate has been developed using a CFD method. A spade rudder is selected as the base rudder model. The developed rudders with almost the same lift forces as the original spade rudder have shorter chord length by 10-20% than the base one. The breadth of the tail is changed from 2.5 to 5.0% of chord length, and an end plate is attached on the bottom of the developed rudders to increase the lift force. The numerical results show that the rudder with 20% shorter chord length, a width of wedge tail 2.5% of chord length and an end plate (0.8c-wedge 2.5-end plate) gives the highest maximum lift force. Likewise, a rudder with 10% shorter chord length, a width of wedge tail 2.5% of chord length and without an end plate (0.9c-wedge 2.5) also produces higher lift than the based rudder. However, all the developed rudders accompany higher drag forces than the based rudder at small angles of attack. At zero angle of attack, the drags increase by 15%, 18% and 22% for the 0.9c-wedge 2.5, 0.8c-wedge 2.5-endplate, and 0.8c-wedge 5.0 rudder models, respectively.

Computational fluid dynamics Lift Rudders Wedges

2015061384

Numerical study on drag force acting on flat plate under transitional and irregular oscillations. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper V-3, p 373 [10 p, 6 ref, 3 tab, 11 fig] http://www.int-nam.yildiz.edu.tr/2014/ Katayama, T., Umeda, J. English

In this study, in order to investigate drag coefficients of flat plate under transitional and irregular motions, numerical simulations (commercial CFD cord Fluent) are performed under one direction accelerating and swing from rest for sinusoidal oscillations and irregular motions. The calculated results have been validated with the published experimental results and it is confirmed the following. The drag coefficient under one direction accelerating is lower than that under steady sinusoidal oscillation in the region of low Kc number. The drag coefficient under sinusoidal oscillation increases from the first swing to the third swing gradually, and it becomes constant value after the third swing. Under irregular motion, the drag coefficient is larger than that under steady sinusoidal oscillation for the present Kc number when the previous swing has larger Kc number than the present swing, and it is smaller than that under steady sinusoidal oscillation for present Kc number when the previous swing has smaller Kc number.

Computational fluid dynamics Drag coefficients Flat plates Motion

2015061385

On the roll motion of a ship with passive anti-roll tank in regular longitudinal waves. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper VII-1, p 531 [15 p, 36 ref, 2 tab, 24 fig] http://www.int-nam.yildiz.edu.tr/2014/ Peşman, E., Ölmez, H., Taylan, M. English

In this study, the influence of a U-tube passive anti-roll tank on parametric roll motion has been investigated as a mechanical absorber of a dynamic

ABSTRACTS 510

system. Specifically, this paper concentrates on how the initial conditions of a coupled roll motion and fluid motion in the tank act on the performance of an anti-roll tank. Parametrically exited roll motion was modeled as a single degree of freedom system incorporating heave and pitch effects by means of a time varying restoring moment. Fluid motion in the tank was modeled as a single degree of freedom system. Coupled equations of motion were solved numerically and the results were presented in time domain. Furthermore, the results were comparatively depicted as maximum roll amplitudes vs. initial values for a ship with and without an anti-roll U-tube tank.

Antirolling tanks Passive systems Rolling

2015061386

The investigation of the motions of an ellipsoid with various length/beam ratios in regular head waves. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper VII-2, p 547 [9 p, 6 ref, 10 fig] http://www.int-nam.yildiz.edu.tr/2014/ Erselcan, I.O., Kükner, A. English

This study describes the comparison of the results of two methods used in the analysis of ship motions. The main objective of this study is to determine the extent of slender body approximation made in 2D linear strip theory. The calculations are based on 2D linear strip theory and 3D pulsating source distribution method. Half-immersed ellipsoids with various length/beam (L/B) ratios were used in the calculations. The hydrodynamic coefficients, wave forces/moments and Response Amplitude Operators (RAO’s) were calculated for each ellipsoid in head seas at zero forward speed. The results show that heave and pitch motions of ellipsoids with L/B ratios 4-8 are predicted closely by linear strip theory to

those predicted by the 3D model. The differences observed in the RAO’s of ellipsoids with L/B ratios 2 and 3 are mainly caused by the differences in diffraction forces.

Ellipsoids Heaving Pitching Ship motions Strip method

2015061387

Motion analysis of 20 ft semi-planing power boat using sea trial test. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper VII-4, p 569 [10 p, 13 ref, 2 tab, 10 fig] http://www.int-nam.yildiz.edu.tr/2014/ Yoon, H.K., Seong, E., Et al English

20 ft power boats of which the hull shape is semi-planing is widely used for leisure, fishing, and passenger transporting. In order for a person to drive such a boat, a driving license issued by the authority is needed for safety, so lots of exercises on sea are inevitable. Since it is not easy for a person to be trained by real sea trial frequently, the simulator having accurate dynamic mathematical model is probably effective. In this paper, real motions of a 20 ft semi-planing power boat in various operating conditions like speed change, course changing, turning, zig-zag, and backing maneuvers were measured on board. To do this, motion measuring system was installed on deck and the standard sea trial procedure for various operating scenarios was established. After the sea trial, the attitudes, speed reduction, and turning diameter depending on the speed and the waterjet bucket angle were analysed in various running scenarios. In the future, those results might be expected to be helpful to confirm the simulation model of 6 DOF motion of 20 ft semi-planing power boat.

Boats Planing hulls Sea trials Ship motions

511 ABSTRACTS

2015061388

Estimation of oblique-wave parametric rolling amplitude using an averaging method. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper VII-5, p 579 [10 p, 14 ref, 1 tab, 2 fig] http://www.int-nam.yildiz.edu.tr/2014/ Sakai, M., Umeda, N., Matsuda, A. English

For developing on-board operational guidance, two simple estimation methods for amplitude of parametric rolling in oblique waves are proposed by applying an averaging method to an uncoupled roll equation with restoring variation due to waves and direct wave excitation in oblique waves. These methods were verified with numerical simulation in the time domain and were validated with physical model experiment for the ship model in oblique waves. No significant difference between the two methods was found. Therefore it is concluded that operational guidance for avoiding parametric rolling could be developed with one of the present estimation methods without time-consuming numerical simulation.

Mathematical models Rolling

2015061389

An investigation of comfort on board calculations for a passenger catamaran and a yacht. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper VII-6, p 589 [16 p, 12 ref, 14 tab, 8 fig] http://www.int-nam.yildiz.edu.tr/2014/ Çakıcı, F., Sukas, Ö.F., Alkan, A.D. English

This study deals with the comfort on board assessment of two different hull concepts based on their seakeeping performances. One of the investigated hull form is a mega yacht while the other one is a catamaran. The seakeeping focused paper concludes the application of commonly used comfort on board methodologies. At first, the ship responses are obtained by using the strip theory and the statistical short term response prediction methods. The analyses are carried out by a reliable commercial

software. Secondly, the motion sickness indices (MSI) and the habitability indices (HIsm) based on ship motions are calculated with respect to given experimental formulation. The MSI calculations are performed for different number of locations, two wave headings and the cruise speeds of the both hulls. However, Hism values are computed only for the yacht hull by considering absolute vertical acceleration criteria suggested by the ISO. Consequently, a practical guide to naval architects on human comfort is provided for yacht and catamaran type of hulls.

Catamarans Motor yachts Ride comfort Seakeeping

2015061390

Dynamic Positioning system of a vessel with conventional propulsion configuration: Modelling and simulation. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 75, p 725 [9 p, 9 ref, 2 tab, 6 fig] http://www.crcpress.com/product/isbn/9781138027275 Alessandri, A., Donnarumma, S., Et al English

A simulation model of the DP system for a conventional naval configuration is presented. A complete mathematical description of the dynamically positioned vessel is developed, including distinct models for low- and wave-frequency ship motions, slowly-varying wind and wave forces, and mechanical constraints on the actuators. A specific allocation logic is devised for such a configuration, by using a linear hydrodynamic model of the propeller-rudder interaction. An anti-windup control-loop correction is designed to improve the DP controller performance. Eventually, simulation results are described to illustrate the effectiveness of the DP system.

Dynamic positioning Mathematical models Simulation

ABSTRACTS 512

2015061391

Influence of wave group characteristics on the motion of a semisubmersible in freak waves. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1A: Offshore Technology, Paper No. OMAE2014-23589 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911384 Deng, Y., Yang, J., Xiao, L. English

In the last few decades, the hydrodynamic performance of offshore structures has been widely studied to ensure their safety as well as to achieve an economical design. However, an increasing number of reported accidents due to rough ocean waves call for in-depth investigations on the loads and motions of offshore structures, particularly the effect of freak waves. The aim of this paper is to determine the sea conditions that may cause the maximum motion responses of offshore structures, which have a significant effect on the loads of mooring systems because of their tight relationship. As a preliminary step, the response amplitude operators (RAOs) of a semisubmersible platform of 500 meters operating depth are obtained with the frequency-domain analysis method. Subsequently, a series of predetermined extreme wave sequences with different wave group characteristics, such as the maximum crest amplitude and the time lag between successive high waves, are adopted to calculate the hydrodynamic performance of the semisubmersible with mooring systems in time-domain. The paper shows that the maximum motion responses not only depend on the largest wave crest amplitude but also the time lags between successive giant waves. This paper provides an important reference for future designs which could consider the most dangerous wave environment.

Freak waves Platform motions Semisubmersibles Wave groups

2015061392

Reduction of pitch motion of FPSO vessel by innovative OWC passive control. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1A: Offshore Technology, Paper No. OMAE2014-23686 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911389 Medeiros, J.S. de, Guimarães, H.B., Fernandes, A.C. English

The improvement of the seakeeping capabilities of Floating, Production, Storage and Offloading (FPSO) vessels increases safety and allows its operation on severe weather conditions. It also increases the fatigue life of the risers. Hence, any improvement on the FPSO motion is mostly welcome. Guimarães, following similar efforts by Silva, studied the reduction of pitch motions of FPSO vessels with the use of the OWCs (Oscillating Water Columns) passive system. However, both experimental and numerical results were inconclusive due to green water effects during experiments and panel issues with the panel code WAMIT, respectively. The objective of the present work is to report a series of new tests that prove the feasibility of an “L-shaped” moon pool concept and estimates and tests the ideal length of such concept that maximizes the restoring moment and minimizes pitch the most.

Control systems FPSOs Passive systems Pitching Seakeeping

513 ABSTRACTS

2015061393

Assessment of extreme rolling of ships in random seas. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4549-3. Volume 7: Professor Emeritus J. Randolph Paulling Honouring Symposium on Ocean Technology, Paper No. OMAE2014-23458 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911977 Dostal, L., Kreuzer, E. English

The goal of this analysis is to improve intact stability criteria for ships. For this, the authors develop analytical formulas for mean first passage times of critical roll amplitudes of ships travelling in long crested random seas with an arbitrary wave encounter angle. Starting from a model for coupled heave-pitch-roll motion, the authors average the fast oscillatory dynamics of roll over the roll period, which yields equations for drift and diffusion of roll energy. The results are used to calculate the desired mean first passage times. Finally, the proposed theory is applied to a sample ship design.

Coupled motion Random seas Rolling

2015061394

A comparison of time domain methods for asymmetric roll predictions. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4549-3. Volume 7: Professor Emeritus J. Randolph Paulling Honouring Symposium on Ocean Technology, Paper No. OMAE2014-23563 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911979 Seah, R., Bigot, F., Et al English

Unlike ocean going vessels, FPSOs often have appendages, such as bilge keels or riser porches, at or below the waterline in an asymmetric configuration. In addition, the riser and mooring systems impose asymmetric loads on the hull. As a result, the expected roll motion response to a wave environment is asymmetric and traditional methodologies cannot be used to predict it. Morison drag elements can be

incorporated to represent the asymmetric condition and are easily implemented in time domain simulations. The limitation to this engineering approach is that the drag coefficient can only be calibrated to produce accurate motions or accurate appendage loads but not both. In this paper the response is compared using two time domain approaches, the first being adapted from a commercial marine dynamics analysis tool and the other being a specialized hydrodynamics motion prediction tool. Here, the commercial tool utilizes constant coefficient drag elements in conjunction with traditional linear equivalent roll damping to model the effect of unequal port and starboard bilge keels as is typical when a riser balcony are present. In contrast, the newly developed hydrodynamic model relies solely on a Keulegan-Carpenter (KC) number dependent drag relation to represent the asymmetric drag contributions. The different calibration procedures are discussed and a comparison for a design environmental condition between the two methodologies is presented.

FPSOs Rolling Time domain

2015061395

A comprehensive identification method for vessel motion parameters. Journal of the Japan Society of Naval Architects and Ocean Engineers, v 20 2014, p 27 [12 p, 13 ref, 3 tab, 18 fig] https://www.jstage.jst.go.jp/article/jjasnaoe/20/0/20_27/_pdf Hane, F. Japanese

This paper proposes a method that identifies ship motion parameters needed to a control system for an autopilot. The autopilot has the function of heading control and tracking control. In order to realize the function by automatic control, it is essential to identify parameters of dynamics of yaw and sway. The proposed method consists of ship motion models, identification models, evaluations of identified values, and identification algorithm. The ship motion models adopt first-order models that approximated second-order models derived from coupled motion between the yaw and the sway. The identification models have constructions based on the ship motion models and can apply practically. The identification algorithm uses a method that focused on minimum problem of multivariate function. Because the ship models have model error explicitly, the identified

ABSTRACTS 514

values are evaluated by the following response errors and the closed-loop stability. Finally, the proposed method verifies the validity by simulations and full-scale experimental data.

Autopilots Control systems Ship motions

2015061396

Influence of side hull arrangement for wave loads acting on cross deck of trimaran. Journal of the Japan Society of Naval Architects and Ocean Engineers, v 20 2014, p 69 [7 p, 9 ref, 3 tab, 9 fig] https://www.jstage.jst.go.jp/article/jjasnaoe/20/0/20_69/_pdf Dobashi, J. Japanese

Influence of side hulls arrangement for wave loads acting on cross deck of trimaran is investigated. The author developed a prediction method for wave loads acting on cross deck of trimaran. The present method is based on strip method and doesn’t consider hydrodynamic interaction between main hull and side hull. An experiment was carried out to measure wave loads acting on the cross deck of a trimaran in head seas with side hull position changes. Results show the vertical shearing force on cross deck increases and pitch connected moment decreases with shifting the side hulls forward. It is confirmed that the present method can evaluate qualitatively the influence of the side hull arrangement for wave loads acting on the cross deck of a trimaran in head seas.

Cross sections Ship sides Trimarans Wave loads

2015061397

On the prediction method for ship motions of trimaran in oblique waves. Journal of the Japan Society of Naval Architects and Ocean Engineers, v 20 2014, p 77 [8 p, 10 ref, 2 tab, 9 fig] https://www.jstage.jst.go.jp/article/jjasnaoe/20/0/20_77/_pdf Dobashi, J. Japanese

The author developed a prediction method for ship motions of trimaran in oblique waves. The present

method is based on the STF method, and doesn’t consider the hydrodynamic interaction between the main hull and side hull. To validate the present method, a tank test was carried out measuring ship motions of a trimaran in oblique waves. Results show that the method gives good agreement with experiments in the case of zero ship speed, and that it can capture ship motions in the case of non-zero ship speed qualitatively.

Oblique seas Ship motions Trimarans

2015061398

Submarine manoeuvres using direct overset simulation of appendages and propeller and coupled CFD/potential flow propeller solver. Journal of Ship Research, v 59 n 1, March 2015, pp 31-48 http://www.ingentaconnect.com/content/sname/jsr/2015/00000059/00000001/art00003 Ezequiel, M.J., Thad, M., Carrica, P. M. English

This article presents two approaches to simulate maneuvers of a model radio-controlled submarine. In the direct simulation approach, rudders, stern planes, and propellers are gridded and treated as moving objects using dynamic overset technology. The second approach couples the overset computational fluid dynamics (CFD) solver and a potential flow propeller code, with both codes exchanging velocities at the propeller plane and wake, body forces, and propeller forces and moments, whereas rudders and stern planes are still explicitly resolved. It is shown that during the maneuvers, the range of advance coefficients does not deviate much from the design point, making a coupled approach a valid choice for standard maneuvering simulations. By allowing time steps about an order of magnitude larger than for the direct simulation approach, the coupled approach can run about five times faster. The drawback is a loss of resolution in the wake as the direct propeller simulation can resolve blade vortical structures. Open water propeller curves were simulated with both the direct propeller approach and the coupled approach, showing that the coupled approach can match the direct approach performance curves for a wide range of advance coefficients. Simulations of a horizontal overshoot manoeuvre at two approach speeds were performed, as well as vertical overshoot and

515 ABSTRACTS

controlled turn maneuvers at high speed. Results show that both CFD approaches can reproduce the experimental results for all parameters, with errors typically within 10%.

Computational fluid dynamics Manoeuvring Propeller flow Submarines

2015061399

A review of short-term prediction techniques for ship motions in seaway. Journal of Ship Mechanics, n 12, 2014, pp 1534-1542 http://www.cssrc.com/ Chen, Y-S., Duan, W-y., Et al Chinese

The survey and assessment of the short-term prediction of techniques ship motions are presented. Description and definition of ship motion short-term prediction are presented, and the categorization and difficulties of short-term prediction techniques are further discussed. Short-term prediction models based on various theories are reviewed and the corresponding characteristics of those approaches are analysed to pinpoint the advantages and disadvantages. Recommendations for further research and development are made.

Predictions Ship motions

2015061400

Analysis of the numerical errors in the application of the 3D moving patch method to ship-to-ship interaction in shallow water, MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 102, p 973 [10 p, 19 ref, 20 fig] http://www.crcpress.com/product/isbn/9781138027275 Zhou, X., Sutulo, S., Guedes Soares, C. English

The numerical errors of the moving patch variant of the 3D panel method applied to the problem of ship hydrodynamic interaction in shallow water are analysed in the case of the flat bottom. The patch moving method is compared to the mirror image method, which is considered as the reference method and results. However the mirror image method has

the string limitation of not being applicable to the case of arbitrary bathymetry, which the moving patch method can handle. It is demonstrated that the errors of the moving patch algorithm remain insignificant when no dynamic re-panelling is applied. Tools and methods for reducing the numerical errors and smoothing the computed responses are investigated.

Error analysis Interactions Numerical analysis Passing vessels Shallow water

2015061401

Numerical simulation of the free surface turbulent flow of a Wigley hull with trim and drift angle. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 106, p 1009 [7 p, 20 ref, 4 tab, 8 fig] http://www.crcpress.com/product/isbn/9781138027275 Tarbiat, S., Lavrov, A., Guedes Soares, C. English

The steady free surface flow around a Wigley hull is studied considering different trims and various Froude numbers. The total resistance coefficient is calculated for different Froude numbers from 0.250 to 0.408. A local-time stepping solver is used to solve the Reynolds Averaged Navier–Stokes equations with the k-ω turbulence model, using the OpenFOAM software. The domain size has been constant following the ITTC recommendation. A grid independence study has been carried out to ensure the best discretization level. The total resistance coefficient and wave profiles are compared against experimental results and it is shown that results are in the good agreement with experimental data for some Froude numbers. Calculations are also made with the ship model in various drift angles in order to obtain the hydrodynamic derivatives required for the manoeuvring equations. By different model orientation based on straight line test the forces and moments on the hull can be plotted against sway

ABSTRACTS 516

velocity and hydrodynamic derivatives of manoeuvring equations can be extracted by these plots.

Free surfaces Numerical models Ship motions Turbulent flow Wigley models

2015061402

Influence of mesh refinement on the motions predicted by a panel code. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 108, p 1029 [10 p, 9 ref, 4 tab, 31 fig] http://www.crcpress.com/product/isbn/9781138027275 Jafaryeganeh, H., Rodrigues, J.M., Guedes Soares, C. English

Definition of the panel distribution constitutes the first step when using linear radiation/diffraction panel codes for seakeeping related studies. Optimisation studies on the compromise between the number of panels and the accuracy of results can be a time intensive task, due to the work required to prepare extra input files, which tends to discourage their practice. In this paper, one such study is carried out where optimised panel size and shape parameters are investigated, taking into account the geometry of the hull, the motion mode and the incoming wave characteristics. The convergence of the hydrodynamic coefficients and the amplitude of the motions are the measures of merit. A set of panel meshes, which discretize a shuttle tanker’s submerged hull, is generated and several statistical quantities, concerning each mesh, are analysed. Correlations identified, between these quantities and the accuracy of the results, should contribute to narrow the bounds of initial mesh configuration in similar seakeeping studies.

Boundary integral method Seakeeping Ship motions

2015061403

Importance of non-linear hydrodynamic forces in ship design. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 109, p 1039 [8 p, 13 ref, 13 fig] http://www.crcpress.com/product/isbn/9781138027275 Sengupta, D., Dutta, A., Datta, R. English

In this present paper, a linear 3D time domain panel method is modified in order to estimate the nonlinear effect on the body boundary condition. Though the scattered potentials are computed in the mean wetted surface, however; in the body boundary condition, exact nonlinear kinematics is used considering the fact that wave particle kinematics has an exponential decay with depth. The proposed method is then applied to a Wigley Hull in order to verify how this change influences the scattered potential. Initially the results are obtained to calculate the diffraction force and then the total hydrodynamic force (radiation + diffraction) is calculated and compared with linear results. From the results, it can be concluded that by modifying the body boundary condition, a significant change is occurs for large wave amplitude and motion results are improved in comparison to the linear results.

Hydrodynamic forces Numerical analysis Seakeeping Wigley models

2015061404

Numerical and experimental study of parametric rolling of a container ship in regular and irregular head waves. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 110, p 1047 [10 p, 30 ref, 5 tab, 8 fig] http://www.crcpress.com/product/isbn/9781138027275 Uzunoglu, E., Ribeiro e Silva, S., Guedes Soares, C. English

This paper deals with the validation of a theoretical model that is employed to foresee the susceptibility of a vessel to the occurrence of parametric rolling. The

517 ABSTRACTS

results of a series of experiments carried out on a C11 type container vessel are compared with the six degrees of freedom numerical code. Severity of the motion is discussed utilizing time series. Regular and irregular head waves are presented and the presence and the effect of coupling are examined. In addition to head waves, irregular waves are numerically and experimentally evaluated also in slightly oblique waves. Numerical results are presented in polar plots for regular and irregular waves for all headings and speeds of the vessel.

Containerships Model tests Numerical analysis Rolling

2015061405

Review of seakeeping criteria for container ship sustainable speed calculation in rough weather. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 111, p 1059 [6 p, 14 ref, 6 tab, 9 fig] http://www.crcpress.com/product/isbn/9781138027275 Mudronja, L., Vidan, P., Parunov, J. English

This paper presents overview of existing seakeeping criteria for ship speed calculation in rough weather, applicable for large container ships. Sea states describing rough weather are given for North Atlantic sea environment according to the IACS recommendation Note No. 34. Criteria are calculated for different ship responses in short-term sea states based on the Response Amplitude Operators (RAO). 3D panel method is employed for computation of RAOs, while 2-P Pierson–Moskowitz wave spectrum is used for short term spectral analysis. Seakeeping criteria considered in the study are slamming, deck wetness, and vertical acceleration at bow. Sustainable ship speed is determined as combination of selected criteria and it is presented in polar plot diagrams for

representative sea states. Practical overview how seamen feel operational criteria and which is sustainable speed in real life is also presented. In the conclusion, critical assessment of criteria is performed and guidelines for future research are provided.

Containerships Criteria Heavy weather Seakeeping Ship speed

2015061406

Responses of an LNG carrier in the presence of abnormal waves. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 114, p 1081 [12 p, 40 ref, 3 tab, 9 fig] http://www.crcpress.com/product/isbn/9781138027275 Zhang, H.D., Guedes Soares, C. English

This paper studies the ship behaviour in the long-crested nonlinear water waves produced numerically by the Nonlinear Schrödinger equation, which is capable of catching the modulational instability and generating abnormal waves. Responses to these wave conditions are also compared with those to the linear wave time series in the same sea state characterized by a JONSWAP spectrum. The comparison is mainly focused on the aspects of the vertical motions, shear forces and bending moments obtained in three typical sea states. As anticipated, with the increased nonlinearity, the presence of a large set of abnormal waves apparently leads to larger ship responses and structural loads. Moreover, it is revealed that the ship responses are not only determined by the wave height but also dependent on the wave length.

LNG carriers Freak waves Ship motions Ship response

ABSTRACTS 518

2015061407

Approximation of towline influence on towed ship motions. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 115, p 1095 [9 p, 14 ref, 2 tab, 11 fig] http://www.crcpress.com/product/isbn/9781138027275 Ćatipović, I., Degiuli, N., Et al English

Towing is often used when setting up offshore objects as well as for the removal of damaged ships from the crash site. For this purpose, quasi-static approach is used for approximation of towline forces acting on towed ship. So, mathematical model of towline takes into account geometric, axial and flexural stiffness while inertial and damping forces are neglected. Towed ship is modelled as a rigid body. Hydrodynamic loadings due to waves are considered along with hydrodynamic reactions i.e. added mass and radiational damping. Usually, these loadings and reactions on a ship are calculated in frequency domain. Since the properties of towline model are nonlinear, calculations should be performed in time domain. Therefore, mapping of hydrodynamic loadings and reactions from frequency to time domain is done. Obtained numerical results are compared with experimental results from available literature where ship’s model is observed on regular head waves.

Mathematical models Ship motions Towed vessels Towing cables

2015061408

Preliminary investigation on automatic berthing of waterjet catamaran. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 116, p 1105 [7 p, 11 ref, 8 fig] http://www.crcpress.com/product/isbn/9781138027275 Ferrari, V., Sutulo, S., Guedes Soares, C. English

A preliminary development of the PID control for automatic berthing of a catamaran with waterjet propulsion is presented. In particular, the problem of

the safe approach to the quay is studied. The mathematical model of the ship manoeuvring and waterjet propulsion is discussed, and then the PID algorithm is developed and applied to the case of a ship moving automatically towards the quay. Numerical simulations are presented and finally conclusions are drawn.

Berthing Catamarans Control systems Mathematical models Waterjet propulsion

2015061409

Simulation of wave action on a moored container carrier inside Sines’ Harbour. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 117, p 1113 [9 p, 16 ref, 21 fig] http://www.crcpress.com/product/isbn/9781138027275 Pinheiro, L., Fortes, C.J.E.M., Et al English

The integrated numerical tool SWAMS (Simulation of Wave Action on Moored Ships) is used to simulate the behaviour of a moored container carrier inside Sines’ Harbour. Wave, wind, currents, floating ship and moorings interaction is discussed. Several case scenarios are compared differing in the layout of the harbour and wind and wave conditions. The several harbour layouts correspond to proposed alternatives for the future expansion of Sines’ terminal XXI that include the extension of the East breakwater and of the quay. Additionally, the influence of wind on the behaviour of the ship moored and the introduction of pre tensioning the mooring lines was analysed. Hydrodynamic forces acting on the ship are determined using a modified version of the WAMIT model. This modified model utilizes the Haskind relations and the non-linear wave field inside the harbour obtained with finite element numerical model, BOUSS-WMH (Boussinesq Wave Model for Harbours) to get the wave forces on the ship. The time series of the moored ship motions and forces on moorings are obtained using BAS solver.

Moored vessels Numerical models Ship motions

519 ABSTRACTS

2015061410

The effects of wave parameters on motion performance of semi-submersible platforms. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 120, p 1137 [8 p, 17 ref, 5 tab, 12 fig] http://www.crcpress.com/product/isbn/9781138027275 Ezoji, M., Gharabaghi, A.R.M., Gol-Zaroudi, H. English

The objective of this study is to evaluate the effects of wave parameters, including height and period, on the motion performance of semisubmersible platforms and to discuss key technical issues related to the global performance response and mooring behaviour in deepwater. After verification of the developed model with a similar platform, a frequency domain analysis was performed. Morison and diffraction theories are used to calculate the wave loads on the members of platform considering their relative geometry to the wave length. The results are presented for heave, surge and pitch motions in various environmental conditions and statistical results of coupled motions with mooring lines are presented as well. It is shown that by increasing the wave period, heave motion spectrum gets closer to the wave spectrum and by increasing wave height; surge motion spectrum gets closer to the desired environmental spectrum. This means that the wave height plays more important role in the surge motion and the period is more effective on heave motion. It is also seen that in some cases, low frequency forces and resonance phenomena have significant impacts on mooring lines and motion of platforms.

Platform motions Semisubmersibles Wave height Wave periods

2015061411

Similarity of rudder effectiveness and speed response of a free-running model ship. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1B: Offshore Technology, Paper No. OMAE2014-23805 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911398 Ueno, M., Tsukada, Y. English

The authors proposed a method, rudder effectiveness correction, to realize full-scale equivalent manoeuvring motion using scale models with the auxiliary thruster. In the method they introduced the rudder effectiveness correction factor to make the effective inflow velocity to rudder defined in a steady straight course similar to a corresponding full-scale ship. The method assumes the factor constant during manoeuvring motion for a model ship running at a constant propeller rate of revolution. In this report the authors propose by a numerical approach a detailed method ensuring more precisely the similarity of manoeuvring motion than the former one. The detailed method takes into account the similarities both of the speed response and rudder effectiveness. The time-varying control both of the propeller rate of revolution and rudder effectiveness correction factor, based on the new method, enables scale model ships to realize the similar manoeuvring motion to full-scale ships more accurately. Simulation calculations using the modular mathematical model of manoeuvring motion clarifies how well the detailed method raise the precision of the full-scale equivalent manoeuvring motion in free-running model ship testing comparing with the former method.

Free running models Manoeuvring Mathematical models Rudders

ABSTRACTS 520

3.4 FLUID STRUCTURE INTERACTION

2015061412

Coupled fluid–structure simulations for evaluating a performance of full-scale deepwater composite riser. Ocean Engineering, v 94, 15 January 2015, pp 19-35 http://www.sciencedirect.com/science/article/pii/S0029801814004193 Tan, L.B., Chen, Y., Et al English

A global–local analysis methodology based on fluid–structure coupling is used to investigate the mechanical responses of both composite and steel risers. Since the design of the riser system can be a daunting task, involving hundreds of load cases for global analysis, semi-empirical fluid load models are considered for the reduced order computations of full-scale riser models. The structural performance of composite risers under real sea current conditions is investigated systematically and discussed with regard to the practical concerns in full-scale settings. The failure envelops of internal liners are found to be within that of the composite layers, which reveals that the liner is the weakest link for composite riser design. Results show that the composite risers can be more prone to vortex-induced vibration (VIV) due to their lower structural frequencies. In the present study, the composite riser yields 25.5% higher RMS strains than the steel riser. Placement of buoyancy modules along the riser may be critical for the design against VIV, and our results show that the modules are not recommended at the top region of the riser, especially if a top-sheared current is expected. Instead, it is preferable to implement them at the bottom-half portion of the riser and as a continuously buoyed region rather than short discrete buoys separated with gap spaces. Composite risers with different metallic liners are studied, and the titanium liner riser is found to be favourable over the steel and aluminium liner risers.

Composite materials Fluid structure interaction Risers Vortex induced vibration

2015061413

Influence of wall proximity on flow around two tandem circular cylinders. Ocean Engineering, v 94, 15 January 2015, pp 36-50 http://www.sciencedirect.com/science/article/pii/S0029801814004302 Wang, X.K., Zhang, J.-X., Et al English

An experimental study was conducted to investigate the flow around two tandem cylinders placed near and parallel to a plane wall. The Reynolds number based on the cylinder diameter (D) was 6300. The cylinder centre-to-centre spacing ratio (L*=L/D) was varied from 1.5 to 6, and the gap-height-to-cylinder-diameter ratio (G*=G/D) from 0.15 to 2. The flow fields were measured using Particle Image Velocimetry (PIV), in conjunction with measurements of fluid dynamic forces (drag and lift) on the downstream cylinder using load cell. The flow strongly depends on the combined value of G* and L*. With reference to G*, the flow could be classified as vortex-shedding suppression regime (G*<0.3), intermediate-gap regime (0.3<G*<1) where vortex shedding occurs but is influenced by wall proximity, and large-gap regime (G*>1) where the wall influence becomes negligible. Similarly, three categories can be identified as a function of L*, namely, extended-body regime 1<L*<2, reattachment regime at 2<L*<4, and impinging regime at L*>4. Variations of dynamic drag and lift coefficients, spectra, Strouhal numbers, and Reynolds shear stress are also presented to characterize the different flow regimes in the G*–L* plane.

Cylindrical bodies Tandem arrangement Vortex shedding Wall effects

2015061414

Re-examination of natural frequencies of marine risers by variational iteration method. Ocean Engineering, v 94, 15 January 2015, pp 132-139 http://www.sciencedirect.com/science/article/pii/S0029801814004387 Chen, Y., Zhang, J., Et al English

Marine risers are important components operating in offshore oil and gas industry. The vortex-induced vibration design of marine risers requires accurate knowledge of natural frequencies and mode shapes. Free vibration of marine risers are re-examined in this

521 ABSTRACTS

paper by means of variational iteration method, which is relatively new technique capable of dealing with eigenvalue problems rather efficiently. Solutions from the variational iteration method are compared to approximate solutions previously proposed in literatures via a numerical example. Furthermore, validation of the technique is demonstrated by comparing experimentally measured natural frequencies of model marine riser with the predicted ones.

Iteration Resonant frequency Risers Vortex induced vibration

2015061415

Vortex induced vibrations at high Reynolds numbers on circular cylinders. Ocean Engineering, v 94, 15 January 2015, pp 140-154 http://www.sciencedirect.com/science/article/pii/S0029801814004296 Belloli, M., Giappino, S., Et al English

The Reynolds Number is a fundamental parameter in defining vortex shedding from circular cylinders. Most of the studies of vortex induced vibrations are at subcritical and critical Reynolds Number values and there is a need to understand how the Reynolds Number affects these oscillations. An experimental set-up was created in a large wind tunnel to study vortex induced vibrations at high Reynolds Numbers. The circular cylinder model had a diameter of 0.72 m, allowing Reynolds Numbers up to 6·105 to be reached. The cylinder had a mass ratio value of 35, quite low with respect to other tests in air because of its large dimensions but still high compared to the mass ratios obtainable testing in water. By increasing the model’s surface roughness it was possible to reach the post-critical flow regime that produces coherent and highly organized vortex shedding. The set-up permitted the simultaneous measurement both of the instantaneous fluid force calculated integrating surface pressure distribution and the model

oscillation. The article describes the results of the tests and compares the characteristics of vortex induced vibrations in post-critical flow regime with subcritical ones.

Cylindrical bodies Pressure distribution Reynolds number Surface roughness Vortex induced vibration

2015061416

A novel method for deriving the diffraction transfer matrix and its application to multi-body interactions in water waves. Ocean Engineering, v 94, 15 January 2015, pp 173-185 http://www.sciencedirect.com/science/article/pii/S0029801814004417 McNatt, J.C., Venugopal, V., Forehand, D. English

A matrix method was developed by Kagemoto and Yue (1986) to compute interactions between multiple three-dimensional bodies subjected to linear water waves. The approach leads to a significant reduction in computational time versus the direct method, in which the boundary value problem is solved for all bodies simultaneously. An essential component of the theory is the so-called diffraction transfer matrix, a linear operator defined for each unique geometry. However, the diffraction transfer matrix is not a standard product of a linear wave computation, for one, because it is based around an unusual representation of incident waves, that is, as partial cylindrical waves. In this paper, a new method is presented to compute the diffraction transfer matrix from plane incident waves, which enables one to derive it from standard wave-body software or experiments. Additionally, a new linear operator – the force transfer matrix, is presented, which can also be determined by usual means. Herein, the interaction theory calculation is verified against direct method results from the linear wave-body software, WAMIT, and then applied to compute absorbed power and wave field effects on a medium-sized array in spectral seas and on a large farm of 101 wave energy converters in regular waves.

Multibody systems Wave diffraction

ABSTRACTS 522

2015061417

Vortex induced vibration excitation competition between bare and buoyant segments of flexible cylinders. Ocean Engineering, v 94, 15 January 2015, pp 186-198 http://www.sciencedirect.com/science/article/pii/S0029801814004612 Rao, Z., Vandiver, J.K., Jhingran, V. English

This paper addresses a practical problem: “Under what fractional coverage of buoyancy modules, would the vortex induced vibration (VIV) excitation on buoyant segments dominate the response?” The source of data is a recent model test on a 38 m long flexible cylinder, densely instrumented with fibre optic strain gauges and accelerometers. A pipe model with five staggered buoyancy configurations was tested. The paper emphasis is on exploring the winner of excitation competition between bare and buoyant segments and offering useful insights on the design of a pipe with staggered buoyancy modules in uniform flow. Four particular topics are covered: (i) the identification of VIV excitation regions, (ii) the experimental determination of the winner of excitation competition between bare and buoyant segments, (iii) the prediction of the winner of excitation competition, and (iv) the factors affecting fatigue damage rate for pipes with staggered buoyancy modules. Potential areas for promising additional research and a general guidance in designing staggered buoyancy pipes are proposed.

Buoyancy Cylindrical bodies Risers Vortex induced vibration

2015061418

Experiments on the water entry of curved wedges: High speed imaging and particle image velocimetry. Ocean Engineering, v 94, 15 January 2015, pp 213-222 http://www.sciencedirect.com/science/article/pii/S0029801814004533 Panciroli, R., Shams, A., Porfiri, M. English

In this work, the water entry of curved rigid wedges is studied experimentally. Experiments are performed on two groups of rigid wedges comprising five specimens each. Each group has a fixed mean deadrise angle (25° and 35°) and varying radius of

curvature. Drop tests are conducted in free-fall, and the drop height is parametrically varied to investigate the effect of the entry velocity on the pile-up evolution, the impact dynamics, and the energy transferred to the fluid. Specifically, high speed imaging is utilized to simultaneously measure the penetration depth of the wedge and its wetted surface. Experimental results are used to compute the pile-up coefficient, which is found to be largely independent of both the wedge geometry and the entry velocity, while exhibiting modest variations as a function of the penetration depth. In addition, particle image velocimetry is used to investigate the flow physics generated by the water entry, and especially dissect the energy absorbed by the risen water during impact. Results show that between 60 and 80% of the impact energy is consistently transferred to the risen water, which accounts for the formation of the pile-up and the spray jets.

Curved shapes Imagery Slamming Water entry Wedges

2015061419

Nonlinear wave evolution above rectangular submerged structures. Journal of Marine Science and Technology, v 22 n 5, 2014, p 531 [11 p, 16 ref, 12 fig] http://jmst.ntou.edu.tw/marine/22-5/531-541.pdf Lee, J-F., Tu, L-F., Liu, C-C. English

In this study, an analytic approach for the complete second-order solution proposed by Sulisz and Hudspeth (1993) was applied to solve a problem of waves propagating over a rectangular submerged structure. In addition, nonlinear wave evolutions above the submerged structure were studied. The nonlinear problem was expressed up to the second-order boundary value problems by using a Taylor series expansion and the perturbation method. In solving the problem, the nonhomogeneous problem was divided into Stokes wave and free wave counterparts. The solutions of neighbouring regions were combined and solved by applying kinematic and dynamic matching conditions. Convergence of the presented theory is examined. The experimental results with and without evanescent modes were compared with previous solutions and effects of evanescent modes can be identified. Further comparisons of the presented theory with previous experimental results also indicated favourable

523 ABSTRACTS

consistency. Using the presented theory, the second-order effects of structural submergence, relative water depth, and wave steepness on wave evolutions were investigated. Parametric studies have indicated that shallow water depths above the structure and shallow relative water depth induce high-shoaling second-order waves. In addition, the second-order wave evolution above the structure increased with the wave steepness.

Underwater structures Wave propagation

2015061420

Numerical and experimental analysis of hydroelastic response on a very large floating structure edged with a pair of submerged horizontal plates. Journal of Marine Science and Technology, v 20 n 1, March 2015, pp 127-141 http://link.springer.com/article/10.1007/s00773-014-0269-y Cheng, Y., Zhai, G., Ou, J. English

This paper aims to investigate the hydroelastic response of the very large floating structure (VLFS) with the perforated, non-perforated or the dual submerged horizontal plates both numerically and experimentally. A modal expansion approach is applied to the fluid–structure interaction problem in the frequency domain. The boundary element method solutions based on Kelvin sources are used for the hydrodynamic diffraction and radiation forces, in which the viscous effect of the perforated anti-motion plate is taken into consideration through the Darcy’s law. As a comparison of the data between calculations and experiments, the relationship between the porosity and the porous parameter is developed using the least-squares fitting scheme. The effectiveness of the attached non-perforated and perforated plates in reducing the motion of the VLFS is systematically assessed for various wave and anti-motion plate parameters, such as plate width, porosity and submergence depth. After simulation and verification, a simple anti-motion device is proposed, which is the perforated-impermeable-plate combination attached to the fore-end and back-end of

the VLFS. The performance of this anti-motion device has been confirmed as an optimal design. Considering variation of the water depths in offshore, discussion on the hydroelastic response of the VLFS with these anti-motion devices at different water depths is highlighted.

Floating structures Hydroelasticity Large size Plates

2015061421

Parallel MPS method for three-dimensional liquid sloshing. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume III, p 257 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Zhang, Y., Yang, Y., Et al English

A parallel MPS method which adopts a domain decomposition strategy based on a background grid strategy and combines a dynamic load balance method for numerical simulations of 3D liquid sloshing problem is presented in the paper. Inter-processor communication is implemented by use of MPI (Message Passing Interface) libraries. Analysis of parallel efficiency is carried out against liquid sloshing in 3D baffled tank by running with different number of processors, showing a satisfactory speed-up rate. Validation is performed by comparing the computed water height and impact pressure with the corresponding experimental data. The presented MPS for sloshing problems is proved to be reliable and efficient. In addition, the effects of baffle on the sloshing are analysed. Sloshing cases in three tanks with different baffle heights are taken into account. The comparison of impact pressure and velocity field shows that the baffle height has significant effects on the sloshing flows. The impact pressure decreases with increasing of the baffle height.

Numerical analysis Sloshing Tanks

ABSTRACTS 524

2015061422

Parametric sensitivity study on liquid sloshing in partially filled tank by numerical simulation. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume III, p 265 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Yu, L., Zheng, J., Xue, M-A. English

Two-dimensional numerical models of liquid sloshing in a partially filled rectangular tank using two CFD programs ADINA and COMSOL, which are both based on the finite-element method and the arbitrary-Lagrangian–Eulerian method, are developed and validated against each other and available analytical solution and experimental data. Natural frequencies of the liquid tank with water are computed using ADINA and compared with analytical solutions. Parametric sensitivity studies are carried out by a series of numerical experiments, which are conducted to investigate the effects of excitation frequencies and filling levels on the liquid sloshing under surge and pitch excitation.

Computational fluid dynamics Sloshing Tanks

2015061423

Physical and numerical large-scale wave basin modelling of fluid-structure interaction and wave impact phenomena. Marine Systems & Ocean Technology, v 9 n 1, June 2014, p 29 [19 p, 45 ref, 2 tab, 35 fig] http://www.sobena.org.br/msot/downloads/MS&OTv9n1.pdf Yim, S.C., Azadbakht, M., Et al English

Physical and numerical large-scale wave basin (LSWB) modelling of fluid-structure interaction (FSI) and wave impact phenomena are examined in this study. In particular, the role of numerical modelling and simulation in design and analysis of physical LSWB FSI and wave impact experiments using a numerical wave basin (NWB) modelling approach is examined. Physical characteristics and testing capabilities of a representative LSWB are first described. Selected physical FSI and wave impact experiments pertaining to civil, energy and naval engineering disciplines conducted at the LSWB and the accompanying NWBFSI modelling and

simulations of these challenging phenomena are presented. An effort to further improve the NWBFSI software with highly nonlinear wave impact modelling capabilities to facilitate physical FSI experiment design and testing, and details of an on-going NWB development and validation processes are delineated. It is demonstrated that the NWBFSI software is useful in facilitating the design of complex, highly nonlinear FSI and wave impact experiments. Conversely, the resulting measured data from the FSI and wave impact experiments can be used to validate and identify further modelling improvement needs of the NWBFSI and wave impact software.

Fluid structure interaction Model basins Numerical models

2015061424

Recent advances in EdgeCFD on wave-structure and turbulence modelling. Marine Systems & Ocean Technology, v 9 n 1, June 2014, p 49 [10 p, 32 ref, 4 tab, 14 fig] http://www.sobena.org.br/msot/downloads/MS&OTv9n1.pdf Elias, R.N., Coutinho, A.L.G.A., Et al English

The computation of free surface flows is challenging since waves are highly nonlinear and commonly present merging, fragmentation and cusps, leading to the use of interface capturing ALE approaches. Turbulence is also important on several offshore applications. This work reports on recent advances of EdgeCFD to simulate these problems. EdgeCFD is a fully implicit 3D incompressible stabilized parallel edge-based finite element flow solver associated to the Volume-of-Fluid (VoF) method. The VoF marking function is also solved by a fully implicit parallel edge-based finite element formulation. Turbulence in EdgeCFD is treated within the Large Eddy Simulation (LES) framework. The performance and accuracy of EdgeCFD is tested in the simulation waves and in the interaction between waves and a semisubmersible structure. The performance of several LES models on the simulation of the flow around a cylinder at Reynolds 3,900 is assessed.

Computational fluid dynamics Fluid structure interaction Free surfaces Turbulence

525 ABSTRACTS

2015061425

Numerical criteria for VIM assessment. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper V-7, p 433 [10 p, 18 ref, 8 fig] http://www.int-nam.yildiz.edu.tr/2014/ Kishev, R., Nikolov, G. English

The phenomenon of vortex induced motions (VIM) has been studied by a numerical method based on ANSYS FLUENT, the specific solution complying with the available computing power. Large number of in-house experimental data has been used for validation of calculation procedure. Besides resulting kinematics, subject of direct comparison of calculations and experiment, the identification and visualization of vortex structures is important for better comprehension of the physics of VIM phenomenon. Several approaches are in practical circulation, but still not generally accepted definition exists. In the paper, a comparison of the most popular numerical criteria for vortex assessment is made and their application is discussed.

Computational fluid dynamics Motion Vortex shedding

2015061426

Hydro-elastic analysis of flexible marine propellers. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 73, p 705 [11 p, 20 ref, 3 tab, 10 fig] http://www.crcpress.com/product/isbn/9781138027275 Maljaars, P.J., Dekker, J.A. English

Hydro-elastic tailoring of flexible composite propellers is a promising technology for improving the overall performance of naval and commercial ships. In this paper a computational procedure is presented to perform the required hydro-elastic calculations. The fluid-structure interaction is modelled by coupling the BEM software Procal (fluid) to the FEM solver Marc (structure). The coupling as presented is limited to steady fluid flows that is uniform wake fields. To partially validate the

developed coupling the calculated predictions of a flexible propeller are compared to the results obtained by a cavitation tunnel experiment of the same propeller. In the last section a parametric study is presented on the influence of the skew angle on the performance of flexible propellers.

Composite materials Flexible materials Fluid structure interaction Hydroelasticity Propellers

2015061427

Determining hydrodynamic coefficients of a cylinder with Navier-Stokes equations. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 105, p 1001 [7 p, 19 ref, 2 tab, 12 fig] http://www.crcpress.com/product/isbn/9781138027275 Gadelho, J.F.M., Rodrigues, J.M., Et al English

A methodology is presented to numerically determine the hydrodynamic coefficients of an oscillating 2D rigid cylindrical body, using a time domain Navier‑ Stokes model. Results for heave and sway motions of a cylinder in deep water are presented and compared with a practical case. The simulations have been performed with the open source Computational Fluid Dynamics OpenFOAM software. Results demonstrate a good agreement of the added mass and damping coefficients between the calculated values and the ones obtained with potential flow formulations.

Computational fluid dynamics Cylindrical bodies Hydrodynamic coefficients Oscillating bodies

ABSTRACTS 526

2015061428

Study on the sloshing load of FLNG. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1A: Offshore Technology, Paper No. OMAE2014-23430 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911367 Zhu, X., Xie, B., Et al English

Due to the characteristics of LNG, the sloshing of a liquid tank in FLNG is inevitable. Therefore, the sloshing load of a liquid tank is one of the hotspots in engineering and academic research. In this paper, in order to simulate the sloshing load of a liquid tank in FLNG, a secondary development software is proposed based on the commercial software FLUENT. The simulation results agree well with previous experimental results. This shows the accuracy of the simulation of the software. In addition, the longitudinal and transverse section of an LNG tank is analysed. The results shows that different excitation frequencies and amplitudes greatly influence the sloshing load of liquid tanks, different filling levels also have a certain influence. This will be used to estimate the size of sloshing load the FLNG equipment may encounter in real sea conditions and have certain significance in practical engineering.

Computational fluid dynamics LNG tanks Sloshing

2015061429

Wave-in-deck load on a jacket platform, CFD calculations compared with experiments. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1A: Offshore Technology, Paper No. OMAE2014-23434 [11 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911368 Iwanowski, B., Vestbøstad, T., Lefranc, M. English

The paper presents an industrial application of CFD for calculation of wave-in-deck loads due to extreme waves. Particular attention is given to flow kinematics initialization that is necessary to start up a

CFD simulation. The applied CFD code, ComFLOW, is a Navier-Stokes equation solver with an improved Volume of Fluid method employed to displace and re-construct fluids free surface. For incoming waves high enough for a negative air-gap and therefore with wave-in-deck loads, a jacket platform was tested in a model basin, for both regular and irregular wave cases. One of goals of these model tests was the verification of CFD codes. The experimental and computational models of the structure are exactly the same. In the paper, the measured wave-in-deck forces are compared with CFD results.

Computational fluid dynamics Jacket structures Wave loads on structures

2015061430

Determination of wave impact loads for the Hebron gravity based structure (GBS). OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1A: Offshore Technology, Paper No. OMAE2014-23503 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911376 Oberlies, R., Khalifa, J., Et al English

ExxonMobil Canada Properties and its co-venturers are building a gravity based structure (GBS) in Newfoundland and Labrador to be installed on the Hebron Field offshore Eastern Canada. This area is characterized by harsh storms with large waves and high winds. The geometry of the Hebron GBS has an effect on the behaviour of the incident waves with regards to their likelihood of breaking onto the shaft. Model tests of the structure in storm waves were executed to provide local wave impact load data on the shaft of the GBS. These tests required significant planning and design of the model, environment, and instrumentation in order to properly satisfy the test objectives. The results of the test showed that the measured wave impact loads on the structure were highly variable, requiring a long-term, response based method to quantify the design loads on an annual exceedance basis. This paper discusses the salient aspects of the model testing effort and the long-term

527 ABSTRACTS

analysis approach which was utilized to define the wave impact loads that were incorporated into the Hebron GBS structural design.

Gravity structures Stresses Wave loads on structures

2015061431

Simulation of multi-liquid-layer sloshing with vessel motion by using moving particle simulation. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1A: Offshore Technology, Paper No. OMAE2014-23565 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911383 Kim, K.S., Kim, M.H., Park, J-C. English

For oil/gas production/processing platforms, multiple liquid layers can exist and their respective sloshing motions can also affect platform performance. To numerically simulate those problems, a new multi-liquid MPS (Moving Particle Simulation) method is developed. In particular, to better simulate the relevant physics, robust self-buoyancy model, interface searching model, and surface-tension model are developed. The developed multi-liquid MPS method is validated by comparisons against Molin et al’s (2012) three-liquid-sloshing experiment and the corresponding linear potential theory. The verified multi-liquid MPS program is subsequently coupled with a vessel-motion program in time domain to investigate their dynamic-coupling effects. In the case of multiple liquid layers, there exists more than one sloshing natural frequencies, so the relevant physics can be much more complicated compared with the single-liquid-tank case. The numerical simulations also show that liquid cargo can function as a beneficial anti-rolling device.

Liquids Motion Simulation Sloshing

2015061432

Wave-in-deck forces on fixed horizontal decks of offshore platforms. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1A: Offshore Technology, Paper No. OMAE2014-23629 [11 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911387 Abdussamie, N., Thomas, G., Et al English

The problem of wave-in-deck loading on offshore structures involves complex physical mechanisms which require close study. In this paper, the wave-in-deck forces generated on the bottom plate of a rigidly mounted, box-shaped structure subjected to unidirectional regular waves are quantified by means of two approaches. The first is an analytical momentum approach recommended by classification societies and the second is a computational fluid dynamics (CFD) approach based on the volume of fluid (VOF) method implemented in the commercial code FLUENT. The change in force due to very small variations in wave steepness and air gap is investigated and discussed. Several numerical trials are conducted to optimise the computational domain and model discretisation suggestions are made. The numerical results are compared with physical model tests recently carried out at the Australian Maritime College. The results of the successive wave impacts are analysed using a discrete wavelet tool to ensure that the temporal information of slamming events is not lost in signal analysis and filtering. By comparing the theoretical and experimental results it was found that in many cases the momentum method underestimates the magnitude of the horizontal and upward directed wave-in-deck forces. Although the three-dimensional CFD cases tested are noticeably time-consuming, these simulations were found to be in good agreement with the experimental measurements.

Computational fluid dynamics Offshore platforms Platform decks Wave forces on structures

ABSTRACTS 528

2015061433

An experimental investigation of cylindrical floater VIM in current and waves. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1A: Offshore Technology, Paper No. OMAE2014-23702 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911391 Saito, M., Fujiwara, T., Maeda, K. English

Vortex Induced Motion (VIM) is one of the important issues in the safety evaluation for cylindrical floating offshore structures. The VIM is basically placed as a phenomenon to occur in strong current, but that also appears in current and waves in the sea where offshore structures are installed. The authors have recognized the phenomenon that the motion amplitude of a cylindrical floater in current and irregular waves together is larger than the sum of the motion amplitude in current and in irregular waves respectively in a VIM experiment. This VIM amplification phenomenon in the current and waves is remarkable when wave height is relatively low that has high occurrence frequency in the sea. It is, therefore, expected that the amplification phenomenon has large influence on the accumulative fatigue damages of the offshore structure’s mooring system. In order to make clear this VIM amplification phenomenon, the authors have conducted detailed VIM experiment in waves using a circular cross sectional mono-column floater model. The results of the VIM experiment in current and waves are described in detail in this paper. The results of the experiment in irregular waves show different characteristics for VIM amplitude in current. The results in regular waves show the effect of wave height and wave period on VIM amplitude in waves. Using those results, the mechanisms of the VIM amplification in waves are investigated.

Cylindrical bodies Floating structures Motion Vortex shedding

2015061434

Conditional stochastic processes applied to wave load predictions. Journal of Ship Research, v 59 n 1, March 2015, pp 1-10 http://www.ingentaconnect.com/content/sname/jsr/2015/00000059/00000001/art00001 Jensen, J. J. English

The concept of conditional stochastic processes provides a powerful tool for evaluation and estimation of wave loads on ships and offshore structures. This article first considers conditional waves with a focus on critical wave episodes. Then the inherent uncertainty in the results is illustrated with an application where measured wave responses are used to predict the future variation in the responses within the next 5‐30 seconds. The main part of the article is devoted to the application of the First Order Reliability Method for derivation of critical wave episodes for different nonlinear wave-induced responses. A coupling with Monte Carlo simulations is shown to be able to give uniform accuracy for all exceedance levels with moderate computational time, even for rather complex nonlinear problems. The procedure is illustrated by examples dealing with overturning of jackup rigs, parametric rolling of ships, and slamming and whipping vibrations.

Monte Carlo method Stochastic processes Wave loads

2015061435

Fully non-linear time domain simulation of 3D wave-body interaction by numerical wave tank. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 107, p 1019 [10 p, 20 ref, 1 tab, 12 fig] http://www.crcpress.com/product/isbn/9781138027275 Abbasnia, A., Ghaisi, M., Guedes Soares, C. English

In this paper, an implicit numerical model has been developed to simulate freely-floating bodies in waves. A three dimensional numerical wave tank has been provided to keep open water condition. Hence, an artificial wave-maker is adopted on the upstream wall and artificial damping zones are spread on the free-surface behind rigid walls to dissipate wave

529 ABSTRACTS

reflection. Potential theory is used to describe flow field and boundary integral equation is applied to solve potential field in the Eulerian frame. The fully non-linear free-surface boundary conditions are implemented by mixed Eulerian-Lagrangian method and Runge-Kutta time integration. The Acceleration potential is used to evaluate the time derivatives of velocity potential implicitly. Wigley hull is chosen as a floating body moves freely. The present model is verified by analytical results, experimental data and numerical solutions. Also, convergence and accuracy tests are conducted. The evolution of the incident wave and time series of response of the body in non-linear regular wave is obtained.

Floating bodies Fluid structure interaction Numerical models Waves

2015061436

Experimental and numerical study on bottom slamming probability of a chemical tanker subjected to irregular waves. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 112, p 1065 [7 p, 21 ref, 4 tab, 8 fig] http://www.crcpress.com/product/isbn/9781138027275 Wang, S., Guedes Soares, C. English

The probability of slamming occurrence of a chemical tanker subjected to irregular waves is studied numerically and experimentally. It is considered that slamming occurrence is dependent upon two conditions: the relative vertical motion at the same longitudinal position of the ship being larger than the vertical distance from the still water to the concerned position, and the entry velocity exceeding some threshold velocity. Model tests are performed to study the ship’s motions under irregular waves and the wave elevations are measured on several positions. In this paper, three irregular sea states are considered and adopted to a numerical procedure based on strip theory. The numerical ship motions are calculated in time domain and compared with the experimental data. The probabilities of bottom

slamming for several ship bow sections are calculated and compared with the experimental data. Under different sea states, the slamming probability distributions along ship length are estimated with the numerical code.

Irregular waves Probability Ship motions Slamming

2015061437

Hydroelastic impact due to longitudinal compression on transient vibration of a horizontal elastic plate. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 113, p 1073 [7 p, 20 ref, 1 tab, 4 fig] http://www.crcpress.com/product/isbn/9781138027275 Wang, S., Karmakar, D., Guedes Soares, C. English

The objective of this study is to analyse the effect of longitudinal compressive force on hydroelastic responses of a horizontal plate impacting with the water surface. The longitudinal bending behavior of a horizontal elastic plate is approximated by the behavior of longitudinal strips represented as an Euler-beam model, and the hydrodynamic pressure is found by solving a two-dimensional boundary value problem in an incompressible and irrotational fluid. An asymptotic solution of hydroelastic responses of the plate is extended to the cases with longitudinal compressive force. The local stresses, strains and deflections are studied theoretically for the cases with two different edge boundary conditions. The effect of the compressive force on the deflection of the beam is studied for the hinged-hinged beam edge boundary condition and a spiral springs supported beam boundary condition.

Compression Elastic plates Hydroelasticity Vibration

ABSTRACTS 530

2015061438

Investigation on the stability of a top-tensioned riser in irregular waves. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume II, p 217 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Xiao, F., Yang, H. English

The stability of steel top-tensioned risers is presented, considering parametric excitation and periodic vortex shedding excitation. Parametric instability is prone to be excited when the frequency of outside excitation and the natural frequency of offshore structures satisfy a certain condition. The prediction of parametric instability of top-tensioned risers in irregular waves based on Hill stability chart is urgently needed. The potential uncertainties of external loadings, geometry, and material properties, and consideration of periodic vortex excitation, make the analysis of instability a more challenging issue.

Risers Vortex induced vibration

2015061439

Numerical confirmation of cloaking phenomenon on an array of floating bodies and reduction of wave drift force. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume III, p 661 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Iida, T., Kashiwagi, M., He, G. English

When multiple floating bodies are situated closely, hydrodynamic interactions among bodies are expected to be large and complex. These hydrodynamic interactions should be taken into account not only in hydrodynamic forces of first order in the incident-wave amplitude but also in time-averaged steady forces of second order which are called the wave drift force. In this paper, it is shown that the wave drift force on a floating body can be reduced to almost zero at a specific wavenumber, by placing extra supporting columns in a way of surrounding the floating body and utilizing the ‘cloaking’ phenomenon. Furthermore to reduce the wave drift force for a wider range of wave

frequencies, the authors propose to control the parameters of outer surrounding columns such as draft and distance from the inner floating body at each frequency. These parameters of surrounding columns are optimised in this paper by a genetic algorithm so as to minimize the total scattered-wave energy. For numerical computations with high accuracy, the wave interaction theory combined with higher-order boundary-element method is adopted and the integral with respect to the azimuth angle in the formula of wave drift force is analytically performed.

Drift forces Floating bodies Interactions Multibody systems Numerical analysis

2015061440

Characterization of self exciting and self-limiting VIV of freely oscillating riser pipes in time domain. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume III, p 354 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Chaudhury, G. English

The ability to predict Vortex Induced Vibration (VIV), at least within engineering accuracy, is very important for deep water risers, flow lines, and wellheads. Uncertainty driven designs and operations cost the industry tremendously. Best practice synchronized perfect lock-in response calculations of VIV and VIM (Vortex Induced Motions) has brought new challenges to all subsea, umbilicals, risers, and flow lines (SURF) designs. A new simplified “Wake-Oscillator” model has been developed to characterize self-exciting and self-limiting nature of vortex induced vibration of transversely oscillating cylinders, in time domain. The model is then extended to capture fluid structure interaction due to inline motions and predict associated vortex shedding induced combined in-line and transverse vibration of a freely oscillating cylinder. This is a novel simple engineering type fluid structure coupling model which will provide time dependent force coefficients along the length of risers and flow lines, based on the characterization of self-exciting and self-limiting nature of VIV. A full direct time integration, using the time and space dependent lift forces, results in a

531 ABSTRACTS

more realistic vibration response amplitudes and frequencies including effects from all participating modes.

Risers Vortex induced vibration

2015061441

Numerical investigation of the vortex induced motion of SPAR in uniform current. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume III, p 362 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Zhao, W., Shen, Z., Wan, D. English

As the development of model ocean engineering techniques, Spar offshore platforms have been widely used in the area of deepwater drilling. Vortex Induced Motions (VIM), a common phenomenon of Spar platforms exposed to flow, is one of the main factors that affect the lifecycle of offshore platforms and should be avoid as much as possible in the design stage. Two common effective ways to mitigate VIM are the configuration of helical strakes and the adjustment of mooring line stiffness. The former could change the flow pattern in the vicinity of Spar hull and the latter can change the Eigen frequency of platforms in still water to avoid resonance frequency. There have been many investigations on Spar VIM both numerically and experimentally. In this paper, VIM of bared cylinder and straked Spar are compared numerically in uniform current at model scale and at different Reynolds numbers. Fundamental study of VIM is done by comparing motion amplitude at different reduced velocity. To predict the motion of Spar, a spring model is employed. To capture the detailed eddy information of the flow, Large Eddy Simulation (LES) is applied. All the simulations are done at a model scale (1:60).

Numerical analysis Offshore platforms Platform motions Vortex shedding

3.5 AERODYNAMICS AND WIND ENGINEERING

2015061442

A study on air drag reduction on the large container ship in the sea. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Ouchi, K. English

Recently, in the case of large container ships, more than half the number of total containers are stowed on deck and the project area above the ship's water line is more than three times of that below the water line, so that the air drag on the ship is not so small enough especially in rough seas. A wind tunnel test and CFD calculation were carried out in the various cases of the windshield and container stowage plan on a 6400TEU container ship. From the experiment, the significant effect of air drag reduction was observed in the case of placing the dome shape front windshield, the side windshield blocking the spaces between every container bay and the sing tail shape stowage in the bays on deck after the accommodation house. By adopting these three ways of air drag reduction, more than 5% (average in a year) of the total fuel consumption will be saved in the real sea of the North Pacific Ocean.

Air Computational fluid dynamics Drag reduction Wind tunnel tests

4.1 STRUCTURAL RESPONSE

2015061443

Hydroelasticity of very large container ships analysed by coupling of 1D structural model and 3D hydrodynamic model. International Conference on Design & Operation of Container Ships; 21-22 May 2014. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Senjanovic, I., Tomić, M., Et al English

Some new results on the hydroelasticity of very large container ships, achieved after presentation on the RINA conference on Design & Operation of

ABSTRACTS 532

Container Ships in 2008, realized within EU FP7 project TULCS (Tools for Ultra Large Container Ships), are presented. An advanced thin-walled girder theory based on the modified Timoshenko beam theory for flexural vibration and analogically developed torsional beam theory is used for formulation of the beam finite element for analysis of coupled horizontal and torsional ship hull vibrations. The model includes bending, shear, torsional and warping stiffness, and rotary inertia. Special attention is paid to the contribution of transverse bulkheads on the open hull stiffness, as well as to the reduced stiffness of the short engine room structure. Also, distortion of transverse bulkheads at transition from open to closed ship cross-section is analysed. In all 3D FEM analysis NASTRAN is used. Another problem related to the ship hydroelasticity is proper definition of restoring stiffness of rigid and elastic modes. Two definitions are considered: consistent one, which includes hydrostatic and gravity properties, and complete one with geometric stiffness as structural contribution. The finite element formulation of the restoring stiffness is presented. The hydrodynamic model, based on the modal superposition method, is briefly described for zero ship speed as the simplest case. The problem is solved by the BV software HYDROSTAR for real ship speed. Beam sectional displacements are transferred to the wetted surface in order to determine modal hydrodynamic forces: damping, inertia and wave excitation. 1D finite element model is verified by comparing dry natural frequencies and modes with those of 3D FEM analysis for an 11400 TEU container ship. Complete hydroelastic response for the same vessel is determined by coupled 1D structural model and 3D hydrodynamic model as well as for 3D structural and hydrodynamic model. The obtained results agree very well. In addition fatigue of structural elements exposed to high stress concentration is considered.

Containerships Finite element method Hull vibration Hydroelasticity

2015061444

Analytical study of the responses of bottom panels to slamming loads. Ocean Engineering, v 94, 15 January 2015, pp 116-125 http://www.sciencedirect.com/science/article/pii/S0029801814004211 Lv, J., Grenestedt, J.L. English

The responses of boat hull bottom panels under slamming loads are studied analytically using a linear elastic Euler–Bernoulli beam as a representation of the cross section of a bottom panel. The slamming pressure is modelled as a high-intensity peak followed by a lower constant pressure, traveling at constant speed along the beam. The slamming response essentially consists of an initial slamming load arriving phase, followed by a vibration phase. The response of the beam is solved analytically. Deflection and bending moment as functions of time and position for different slamming speeds, bending stiffness’s, etc. are given. The response during the two phases are studied and compared. The maximum deflection and bending moment occur approximately when the time it takes for the slamming load to traverse the beam is comparable to the lowest natural period of the beam. At higher slamming speeds the response is less, and the responses do not peak out until after the slam has traversed the beam (i.e., it occurs during the vibration phase). The importance of the leading high-intensity pressure peak often encountered during slamming is also studied. It is seen that a high peak pressure does not necessarily lead to a large structural response, whereas the total load of the peak of the slam does influence the structural response significantly. For relatively slow moving slamming loads, this influence is limited. However, for faster moving loads it can be substantial.

Beam theory Hull bottoms Slamming Structural response

533 ABSTRACTS

2015061445

Nonlinear free vibration of a steel catenary riser. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume II, p 195 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Klaycham, K., Athisakul, C., Chucheepsakul, S. English

This paper presents a finite element method for nonlinear free vibration analysis of a steel catenary marine riser. The energy method based on the Hamilton’s principle is used to derive the nonlinear equation of motion. The work-energy functional is composed of the strain energies due to axial deformation and bending and also the works done by inertia forces of riser and transporting fluid motions. The nonlinear stiffness matrix, the mass matrix, and the gyroscopic matrix of the riser system are developed by using the finite element technique. Consequently, the nonlinear natural frequencies and their corresponding mode shapes are determined by solving the eigenvalue problem incorporating with the direct iteration technique. The examples of large amplitude free vibration of the steel catenary riser with various horizontal offsets and top tensions are also presented in this paper.

Finite element method Free vibration Resonant frequency Risers

2015061446

Structural performance of deepwater lazy-wave steel catenary risers for FPSOs. ISOPE 2014, 24th International Ocean and Polar Engineering Conference; 15-20 June 2014; Busan, Korea. Published by ISOPE, Cupertino, CA, US. ISBN 978-1 880653 91-3. Volume II, p 202 http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202014/index.htm Kim, S., Kim, M-H., Et al English

In this paper, the structural performance of deepwater lazy-wave steel catenary risers (LWSCRs) connected to a FPSO is investigated by using hull/mooring/riser coupled dynamic analysis program. Conventional deepwater steel catenary risers (SCRs) connected to the same FPSO hull exhibit significant dynamic responses, which induces large structural stress amplification and local dynamic buckling at the

members nearby touchdown region. The corresponding short-term fatigue damage is also serious. On the other hand, LWSCRs eliminate the possibility of local dynamic buckling and significantly reduce the maximum stress level near TDZ (touch-down zone). It is because the riser motion can be isolated from the motion of the floater by the intermediate sag and arch members in the lazy-wave configuration. The general performance of SCRs and LWSCRs is directly compared under the same environmental and floater conditions in terms of ultimate limit state and fatigue limit state. It is shown that LWSCRs show excellent structural performance under severe environmental condition because of the motion isolation effect induced by the geometric characteristics. In addition, the effect of the curvature of the sag and arch members on the dynamic response of LWSCR is also studied to seek the optimal shape.

Buckling FPSOs Risers Structural response

2015061447

Improvement of the collision resistance of ships and its experimental and numerical validation. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper I-3, p 43 [11 p, 24 ref, 9 fig] http://www.int-nam.yildiz.edu.tr/2014/ Fricke, W. English

One important aspect of ship safety is collision resistance which has gained increased significance after several accidents. Not only environmental aspects such as oil pollution are in focus, but also the safety of people and cargo on board passenger ships, ro/ro ferries and other vessels. Double hulls are required for several ship types; however, dangerous situations still occur if the inner hull is penetrated during a collision. Effective structural modifications to improve collision resistance can be investigated by experiments or, as these are rather expensive, by numerical simulation taking into account all nonlinear effects due to geometric and material behaviour. Several investigations have been performed at Hamburg University of Technology with the aim of improving the collision behaviour of ship structures and these are reviewed in the paper. Both, numerical simulations as well as quasi-static experiments were

ABSTRACTS 534

carried out, the latter with a special test plant designed for collision forces up to 4,000 kN and for test models scaled down from reality by a factor of about three. Three different investigations are described in the paper, the first looks at the striking ship, in particular at the bulbous bow, which frequently behaves like a rigid body during collision, but could be made softer, thus increasing the dissipated collision energy. The second and third investigations were aimed at modifications of the ship side structure, either by so-called plate strengthened stiffeners or by filling light-weight granulate material into the double hull, which can be easily removed for inspections. For all investigations, the absorbed energy until penetrating the inner hull is determined for both conventional and improved structures, which is a good parameter for assessing improvements of the collision resistance.

Bulbous bows Collision resistance Energy absorption Reinforcement (structures)

2015061448

Development of TSEA software for predicting high-frequency acoustic and vibrational responses in vessels and offshore structures. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper II-4, p 111 [9 p, 7 ref, 4 tab, 12 fig] http://www.int-nam.yildiz.edu.tr/2014/ Yang, H.M., Park, Y.H. English

Offshore structures, ranging from fixed platforms to semisubmersibles and FPSOs, can have noise, shock and vibration problems similar to those found on vessels. Statistical energy analysis (SEA) is a representative prediction tool of high frequency dynamic responses in built-up structures. In this paper, transient statistical energy analysis (TSEA) software was developed to predict high frequency shock besides noise and vibration in vessels and offshore structures. This software covers the acoustic and vibrational energetics of built-up structures composed of acoustic cavities and plates, and is implemented by MATLAB language. The data structure and algorithm of the software were

developed to use reliable SEA parameters (damping loss factor, coupling loss factor, radiation loss factor, etc.) by an experimental database. Simple applications to a vessel’s superstructure were successfully performed.

Acoustics Energy methods Offshore structures Statistical analysis Vibration

2015061449

On the geometrical non-linearities of the ship load expressions. INT-NAM 2014, 2nd International Symposium on Naval Architecture and Maritime; 23-24 October 2014; Istanbul, Turkey. Proceedings. Organised and Published by Yildiz Technical University, Istanbul, Turkey; ISBN 978-605-4123-31-5. Paper VII-3, p 557 [11 p, 15 ref, 8 fig] http://www.int-nam.yildiz.edu.tr/2014/ Acanfora, M., Coppola, T. English

In structural analysis a fundamental rule is played by the internal forces and moments: they are the only variables on which the study for the primary level of the ship structural response is based, in accordance with beam theory. First of all, based on the usual decomposition of loads general expressions for the distributed still water, inertial and restoring loads have been revisited. Additionally, the influence of the non-linearity arising from the hull geometry on loads has been studied. Particular attention has been also given to the evaluation of loads due to the dynamic pressure in wave. Finally, two numerical examples have been carried out in order to verify the aforementioned influence on loads. The results obtained have been particularly discussed.

Structural analysis Wave loads on ships

535 ABSTRACTS

2015061450

Eigenvalue analysis of stiffened plates resting on elastic foundation. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 52, p 495 [7 p, 14 ref, 10 tab, 10 fig] http://www.crcpress.com/product/isbn/9781138027275 Taczała, M., Buczkowski, RF. English

A problem of the eigenvalue analysis of stiffened plates resting on elastic foundation is addressed in the present paper. Equations are derived formulated using Kirchhoff and Reissner-Mindlin plate theories in the framework of the finite element method. The elastic foundation is modelled using one-parameter Winkler and two-parameter Pasternak model. The formulation is verified against the results available in the literature. Accuracy and convergence of results obtained using various types of finite elements is discussed. Influence of parameters of the elastic foundation on the structural response of a stiffened panel is investigated.

Eigenvalues Stiffened plates Structural response

2015061451

Innovative de-coupling materials for the isolation of ship cabins. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 59, p 565 [9 p, 5 ref, 1 tab, 20 fig] http://www.crcpress.com/product/isbn/9781138027275 Badino, A., Rizzuto, E. English

One of the key points for the success in the construction of cruise ships is the enhancement of high standards for passengers comfort on board, especially in the living and resting areas. For this reason, one of the fields on which research in this sector is focused on is the reduction of airborne and structure-borne noise transmitted inside the cabins. At present, the floating floor arrangement is commonly used on board in order to reduce the structural noise transmitted through floors. This special floor decouples the inner floor of the cabin from the load-

carrying structure of the deck. In the present study, the performances of two floating floors with innovative de-coupling materials have been analysed. The floors were tested in the condition of unloaded floor and loaded floor. Modal analysis techniques have been applied to understand the overall results obtained in terms of general indicators

Accommodation spaces Ship decks Vibration analysis

2015061452

Fatigue crack growth analysis of a plate accounting for retardation effect. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 61, p 585 [9 p, 44 ref, 12 fig] http://www.crcpress.com/product/isbn/9781138027275 Yeter, B., Garbatov, Y. English

This work presents a fatigue crack analysis of a plate accounting for the retardation effect under spectrum loading. In a harsh environment, an offshore wind support vessel can encounter possible freak waves. This overloading condition is investigated over a centre-cracked plate and its retarding effect on the fatigue crack growth is estimated. The Wheeler and Willenborg retardation models are employed to analyse the crack growth through the cycle-by-cycle analysis. The retardation effect is studied accounting for the magnitude, the time interval and the cycle sequence. An equivalent stress is estimated that can be used for a design purpose for each load case studied here. The result of this study may be employed to set a framework for an optimal maintenance planning for cracked structural details.

Crack propagation Fatigue cracks Plates Variations

ABSTRACTS 536

2015061453

Life cycle fatigue management for high speed vessels by integrating structural health monitoring data. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 62, p 595 [9 p, 12 ref, 8 fig] http://www.crcpress.com/product/isbn/9781138027275 Zhu, J., Collette, M.D. English

Further developments in a life cycle fatigue management approach by integrating measured bending moment data and crack inspection records is presented, with a focus on comparing different forms of the lifetime updating model structure. A lifetime load updating strategy is proposed for the lifetime fatigue load distribution via limited load measurements. A dynamic Bayesian network-based stochastic crack growth model is constructed to incorporate crack inspection results and update the fatigue parameters for a more accurate future life prediction. This framework is demonstrated for a cracked stiffened panel on the deck of a joint high-speed sealift ship. The results demonstrate that by incorporating both load data and crack inspection records into the proposed structural health monitoring framework, more accurate crack size prediction and reliability estimation are both achieved. The structure of the lifetime load updating model is shown to have a significant impact on the final results.

Fatigue life High speed vessels Structural monitoring

2015061454

Short-term probabilistic combination of wave and whipping bending moments. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 67, p 647 [8 p, 13 ref, 1 tab, 10 fig] http://www.crcpress.com/product/isbn/9781138027275 Ćorak, M., Parunov, J., Guedes Soares, C. English

Extreme values of wave and whipping loads are determined by different calculation procedures in the preliminary design stage. The extreme values do not

occur at the same time so probabilistic load combination methods should be used for determination of the maximum combined bending moment. A correlation analysis between wave and whipping bending moments is performed and a practical method for calculation of the most-probable short-term load combination factor between considered bending moments is presented. The method is based on the reconstruction of the time signal from the frequency domain. The calculated short-term load combination factors are included in the short-term probability density function of the combined bending moment. Since large container ships can experience a significant whipping response, the method is demonstrated on the example of a 4400 TEU container ship.

Bending moments Extreme values Probability Wave loads Whipping

2015061455

RPD analysis of jack-up rigs using 3D models. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4537-0. Volume 1A: Offshore Technology, Paper No. OMAE2014-23511 [13 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911378 Chakrabarti, P., Chawan, A. English

Rack Phase Difference or RPD may occur during jacking up at a location when the jack-up spudcan is eccentrically supported on the bottom or has lateral offset and the resulting moment and shear is carried essentially by the horizontal guide reactions. The RPD is the difference in vertical positions of rack teeth of different chords of one leg. This is a result of vertical shear deformation of the adjacent chords of one leg of a trussed jack-up. This paper discusses analysis of a 3D model of the jack-up that uses non-linear analysis methods for including large deformations and rotations. The nonlinearities come about due to physical reasons, such as pinion-rack contact is compression only and guide contact is also compression only with a gap. In addition, one may like to include nonlinearities due to geometric stiffness for large deformations and plasticity effects. Geometric stiffness allows it to include so-called P-delta effects and simulate buckling behaviour of beam

537 ABSTRACTS

elements. The results of such 3D non-linear analysis for various levels of assumptions are compared with a more traditional single leg analysis. The paper brings out the important differences in behaviour of these two types of models and discusses the importance of those in the analysis results. The authors think that the meaning of RPD has to be understood properly in relationship with moment or shear carrying capacity at the spudcan for a given jack-up. The behaviour of a trussed leg jack-up depends heavily on the bracing pattern, chord and bay spacing as well as the size of the braces. The paper discusses these aspects also. Finally, although the analysis is for one particular jack-up, it recommends the most appropriate modelling for RPD analysis for similar jack-up rigs that could be beneficial to other rigs.

Environmental loads Jackup platforms

2015061456

Free vibration analysis of rectangular plates with multiple rectangular openings and arbitrary constraints. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4542-4. Volume 4A: Structures, Safety and Reliability, Paper No. OMAE2014-23051 [8 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911591 Cho, D-S., Vladimir, N., Choi, T-M. English

Free vibration analysis of plates with openings represents an important issue in naval architecture and ocean engineering applications. Namely, they are often primary design members of complex structures and knowledge about their dynamic behaviour becomes a prerogative for the proper structural design. This paper deals with application of assumed mode method to free vibration analysis of rectangular plates with multiple rectangular openings at arbitrary defined locations. Developed method can be applied to both thin and thick plates as well as to classical and non-classical edge constraints. In the assumed mode method natural frequencies and mode shapes of a corresponding plate are determined by solving an eigenvalue problem of a multi-degree-of-freedom system matrix equation derived by using Lagrange’s equations of motion. The developed procedure actually represents an extension of a method for the natural vibration analysis of rectangular plates without openings, which has been recently presented

in the relevant literature. The effect of an opening is taken into account in a simple and intuitive way, i.e. by subtracting its energy from the total plate energy without opening. Illustrative numerical examples include dynamic analysis of rectangular plates with single and multiple rectangular openings with various thicknesses and different combinations of boundary conditions. Also, the influence of the rectangular opening area on the plate dynamic response is analysed. The comparisons of the results with those obtained using the finite element method is also provided, and very good agreement is achieved. Finally, related conclusions are drawn and recommendations for future investigations are presented.

Free vibration Rectangular plates Vibration analysis

2015061457

Ultimate longitudinal strength of ships’ hull girder under combined loading – 2nd report: development of simplified analysis method. Journal of the Japan Society of Naval Architects and Ocean Engineers, v 20 2014, p 137 [9 p, 12 ref, 1 tab, 15 fig] https://www.jstage.jst.go.jp/article/jjasnaoe/20/0/20_137/_pdf Tanaka, Y., Hashizume, Y., Et al Japanese

FEM analysis using fine-mesh shell models has been increasingly applied to the ultimate longitudinal strength analysis of ship's hull girder. However, the cost and elapsed time necessary for FEM analyses including FE modelling are still large for the design stage. Therefore, it is a common procedure to apply the Smith's method and to evaluate approximately the maximum longitudinal bending strength of a specified cross section. In this case, the effect of shear and warping stresses, which is significant in very large container ships, is not considered. The objective of this study is to propose a method of the analysis of ultimate hull girder strength under combined bending and torsion. The hull girder is modelled by a series of thin-walled beam elements and the average stress-average strain relationship of plate and stiffened panel segments under axial loads considering the effect of shear stress is implemented in the beam elements. The shift of instantaneous neutral axis and shear centre can be automatically considered by introducing axial degree of freedom as well as the bending ones in the beam elements, and keeping the zero axial load condition. The proposed simplified method is applied

ABSTRACTS 538

to the test model explained in the 1st report. First, bending and torsional moment is applied to the beam model for a whole model within the elastic range. Then, the ultimate bending strength of cross sections is calculated applying the Smith's method to a beam element considering the warping and shear stresses. On the other hand, nonlinear explicit finite element analyses are adopted for analysis of the test model by using LS-DYNA. The effectiveness of present simplified analysis method of ultimate hull girder strength under combined loads is discussed comparing with the results of experiments and LS-DYNA analyses.

Combined loads Hull girders Longitudinal strength Ultimate strength

2015061458

Probabilistic load combination factors of wave and whipping bending moments. Journal of Ship Research, v 59 n 1, March 2015, pp11-30 http://www.ingentaconnect.com/content/sname/jsr/2015/00000059/00000001/art00002 Ćorak, M., Parunov, J., Guedes Soares, C. English

Extreme values of wave and whipping bending moments are important in structural design of large containerships. Since the extreme values of these two, partially correlated processes do not occur at the same time instant and even at the same environmental conditions, it is necessary to combine them by using probabilistic load combination methods. The correlation analysis between wave and whipping bending moments is performed and a practical method for calculation of the most probable load combination factor between considered bending moments is presented. Short-term load combination factors are calculated by reconstruction of the signal from the frequency domain solution. Results are validated by comparison with model test data of the 9400-TEU containership for various sea states and speeds and heading angles. Practical regression equations for estimation of the most probable short-term load combination factor are formulated. Regression equations are then used in the

computation of the long-term distribution of combined bending moment. The procedure is demonstrated on the example of the two large containerships.

Bending moments Containerships Slamming Whipping

2015061459

Inverse ice-induced moment determination on the propeller of an ice-going vessel. Cold Regions Science and Technology, v 112, April 2015, pp 1-13 http://www.sciencedirect.com/science/article/pii/S0165232X14002274 Ikonen, T., Peltokorpi, O., Karhunen, J. English

This paper presents inverse methods to determine the ice-induced moment on the propeller based on shaft line torque data. The following methods are applied: Truncation of singular value decomposition (TSVD), truncation of generalized singular value decomposition (TGSVD) and Tikhonov regularization. The dynamic behaviour of the structure is modelled by combining an increment form of the governing equation of torsional vibration and Newmark-β method. Inverse methods are applied on model-produced verification data and full-scale measurement data. The verification indicated that the methods are capable to solve the ice moment function in loading events where multiple consecutive ice contacts are present. Results with full-scale data were physically understandable. The three presented loading events had 1 to 4 individual ice contacts. Durations of these ice-propeller contacts were mostly 60 to 80 ms. Ice contacts were observed to have a secondary peak that could be caused by a shear stress wave propagating back and forth the shaft line. After the ice contacts, the moment caused by the damping effect of water can be seen in the results.

Ice loads Strain measurement Torque

539 ABSTRACTS

2015061460

Evaluation, design and optimisation for strength and integrity of polar class propellers. Cold Regions Science and Technology, v 112, April 2015, pp 31-39 http://www.sciencedirect.com/science/article/pii/S0165232X15000270 Liu, P., Bose, N., Veitch, B. English

An advanced 3D unsteady panel method was developed for the design and optimisation of the strength and integrity of polar class propellers. Blade ice loading specification in both milling and impact cases, under the Unified Polar Class Rules (URI3), by the International Association of Classification Societies (IACS), was implemented. An optimisation example and analysis were given for an R-class propeller. The strength of the R-class propeller was assessed for all 7 polar classes and 5 loading cases. Comparison was also made for all polar classes and ice loading cases. As the blade has little skew with a wide chord, both the spindle torque and the in-plane bending moment are small, so only out-of-plane bending failure is the key factor for strength. It was also found that by URI3, there is little difference in strength requirement between polar classes 1 (strongest requirement) and 7 (the weakest). An integrity design and optimisation example showed a saving of 1.4 tonnes of blade material (22% saving) by decreasing the safety factor to 1.51 (the minimum safety factor under URI3 is 1.5), for which case the blade thickness is about 80% of the existing design.

Fluid structure interaction Icebreakers Propeller ice interaction Propeller strength

2015061461

Research on the design of hull crashworthiness structure based on sandwich plate system. Journal of Ship Mechanics, n 12, 2014, pp 1505-1514 http://www.cssrc.com/ Liu, K., Tang, W-y., Et al Chinese

Sandwich Plate Systems (SPS) with superior mechanical performance are widely used in ship repairing. The core has good buffer function so that it can be used as crashworthiness structures. Based on ABAQUS, the crashworthiness of a SPS side structure under collision load was analysed, such as damage deformation, collision force and energy absorption. Then the crashworthiness of SPS was

compared with traditional side structure. The results show that SPS side structure has better crashworthiness than traditional side structure.

Collision resistance Energy absorption Sandwich structures Ship sides

2015061462

Ultimate residual strength prediction of oil tanker after structural damage by a side collision. Chinese Journal of Ship Research v 9 n 6, December 2014, p 26 [8 p, 10 ref, 5 tab, 15 fig] http://www.ship-research.com/EN/abstract/abstract1212.shtml Sun, B., Hu, Z., Et al Chinese

In a ship collision scenario, the damage on an oil tanker's side structure is closely related to the shape of the striking ship's bulbous bow, and the damaged structure should not be simplified as the volume of the damaged structure. In this paper, three typical collision scenarios are considered. A simplified analytical method for predicting the residual ultimate strength of the struck oil tanker is proposed based on the principles of analytical Smith method and the plastic-elastic deformation mechanism of the tanker's side structures. The proposed method is verified through a comparison between the experimental results of three typical box girders. The results indicate that the proposed method can successfully evaluate the residual ultimate strength of the struck oil tanker accurately and efficiently.

Ship collisions Tankers Ultimate strength

ABSTRACTS 540

2015061463

Uncertainty in stress concentration factor computation for ship fatigue design. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4542-4. Volume 4A: Structures, Safety and Reliability, Paper No. OMAE2014-23129 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911598 Ogeman, V., Mao, W., Ringsberg, J.W. English

In stress-based fatigue design and analysis of marine structures, a stress concentration factor (SCF) is used to compute the local stress in structural details when the hot-spot approach is used. For a typical steel material, the fatigue damage is computed as proportional to the power 3–5 of the stress values, defined by the chosen S-N curve. This means that a small change in the SCF value can lead to a large difference in the fatigue damage result and corresponding fatigue life prediction. Thus, the methodology used to compute the SCF should be clearly defined in classification society guidelines. This study presents a review of different direct calculation procedures for how to obtain the SCF based on fatigue assessment guidelines. The effect of different element types and local stress extrapolation methods to the fatigue damage estimation is studied for both longitudinal load and bending load conditions in a container ship. A simple structural detail with cracks observed after only a few years in service is used for the case study. For this structural detail, two alternative methods to compute the local stress for fatigue assessments are compared. The difference in fatigue life prediction using the proposed approaches is compared; with at least 50% difference expected even within the guidelines from the same classification society. It is further discussed how to reduce the SCF with the objective to increase the fatigue life.

Fatigue life Stress concentration Uncertainty

2015061464

Assessment of residual ultimate hull girder strength of damaged ships. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4542-4. Volume 4A: Structures, Safety and Reliability, Paper No. OMAE2014-23153 [6 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911601 Jiang, X., Yu, H., Kaminski, M.L. English

The risk of ship collision and grounding has increased significantly in recent years as a result of the growing size and number of ships at sea. The potentially costly consequences of collision and grounding in the form of fatalities, property, and cargo, as well as environmental pollution in the form of oil spills, etc., are the main motivations for research on collision and grounding. From a structural evaluation standpoint, there is a great deal of uncertainty related to the residual strength of damaged ships considering various influential parameters, such as damage size, geometry and location, internal structural arrangement, material property, loading case, and sea weather. Therefore, it is important to clarify the residual hull girder strength of damaged ships by collision or grounding in order to ensure their safety. This present study undertook a deliberate finite element analysis to investigate the residual ultimate strength of damaged ship hull, where two damage models were assumed and compared. One model simulated actual damage resulting from an accident in the form of hole with adjacent plastic deformation, while the other applied simplified damage, considering unavailable measurement of the damage by removing the damaged part from the original ship hull. The comparison showed that the assessment of residual ultimate strength of a damaged ship based on the simplified damage model could produce a sufficiently accurate result and stay slightly safer, provided that a reasonable criterion of simplification was defined first. The studies showed that it is possible to accurately estimate the residual ultimate strength of a damaged ship without detailed measurement of the damage, and consequently facilitate decision-making regarding the ship salvage under emergency.

Hull damage Hull girders Ultimate strength

541 ABSTRACTS

2015061465

Ultimate shear strength of stiffened panels for offshore structures. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4542-4. Volume 4A: Structures, Safety and Reliability, Paper No. OMAE2014-23155 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911602 Santos Rizzo, N.A. dos, Amaral Amange, D. do, Estefen, S.F. English

Structures in civil, naval and aeronautical engineering commonly use plates that experience shear loading. When subjected to loading, such as shear, axial compression, bending and lateral pressure, many panel designs use stiffeners to reinforce the structure and increase the buckling capacity. Particularly, in the oil industry, platform side shell structures are made up of stiffened panels that experience a considerable amount of shear force. When added to geometrical imperfection (e.g. fabrication or supply vessel collision), this compromises the ultimate strength capability. The aim of this study is to develop a simplified model, using FEM, to predict the ultimate loading capability of stiffened panels under pure shear stress. Furthermore, an amplified parametric study varying the geometry and initial imperfection was considered to verify such influences. Comparison with several current and published studies yielded positive and conclusive results.

Buckling Compression Offshore structures Shear strength Stiffened plates

2015061466

Progressive collapse analysis and reliability of a damaged hull girder. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4542-4. Volume 4A: Structures, Safety and Reliability, Paper No. OMAE2014-23210 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911608 Ibekwe, A.U., Pu. Y.C., Et al English

With the expectation of hull girder asymmetry and corresponding shift in elastic neutral axis resulting from collision damages and other forms of structural deteriorations, the interaction of vertical and horizontal hull girder capacities become quite significant in the assessment of ship structural safety. This paper therefore extends the application of a previously proposed interactive-numerical probabilistic based methodology for structural safety to assess the hull girder ultimate strength reliability of a damaged ship by means of a user-defined numerical framework. Hull girder capacity is calculated using the NS94D ultimate strength code, which is based on the Smith’s progressive collapse method. The resulting deterministic responses have been interactively linked to the NESSUS probabilistic framework so that the reliability of the damaged hull girder is predicted using an implicit limit state function defined based on a transformation of coordinates to appropriately account for any shift in the neutral axis. Random deviations of the constituent variables are directly applied to calculate the ultimate strength deterministic responses, thereby circumventing the need to characterize any correlated strength variable, which is at best subjective. The conventional approach of characterizing ultimate strength by an assumed coefficient of variation and distribution type was found to be conservative in predicting structural safety of ships relative to the proposed method. Application of the interactive-numerical technique for structural reliability is therefore considered significant for problems involving correlated random variables with unknown

ABSTRACTS 542

statistical characteristics. The method is being considered to predict the safety of cracked hull girders by accounting for the residual strength and further load bearing capabilities of deteriorated and adjacent elements.

Collapse Hull damage Hull girders Structural reliability

2015061467

Long-term prediction of combined wave and whipping bending moments of container ships. Ships and Offshore Structures, v 10 n 1, 2015, pp 4-19 http://www.tandfonline.com/doi/full/10.1080/17445302.2013.833022#abstract Ćorak, M., Parunov, J., Guedes Soares, C. English

The purpose of this paper is to propose a practical computational procedure for the long-term distribution of combined wave and whipping bending moments (BMs) of container ships. The problem is formulated in the frequency domain using standard engineering tools for load computation: a seakeeping code for the rigid-body response and a beam finite element model for transient vibratory response. The von Karman approach with correction for pile-up effect is employed for bow flare slamming load assessment. Correlation between wave and whipping BMs is considered. The procedure is demonstrated on the example of a 9200 TEU container ship. Long-term distributions of combined BMs are computed using the standard International Association of Classification Societies scatter diagram for the North Atlantic environment and two additional scatter diagrams for common shipping routes of container ships. The speed profile required for the long-term load prediction is calculated by the seakeeping analysis respecting operability limiting criteria. Conclusions about influence of various environmental and operability parameters are drawn.

Bending moments Combined loads Containerships Whipping

2015061468

Linear and nonlinear FE analyses of a container vessel in harsh sea state. Ships and Offshore Structures, v 10 n 1, 2015, pp 20-30 http://www.tandfonline.com/doi/full/10.1080/17445302.2013.870773#abstract Ringsberg, J.W., Li, Z., Et al English

Container vessels have a challenging structural design with respect to fatigue; they are long and slender and have large openings in the deck. Their structural design in combination with high wave loads makes these ships sensitive to fatigue damage. Classification societies mainly base their assumptions in the fatigue rules on elastic material response and the fatigue analysis is carried out using the stress-based approach. However, for harsh sea states the assumption of elastic material response is not fulfilled in local details where the stress concentration is high; cyclic plasticity may occur, which requires a strain-based fatigue assessment. The objective of this study is to present a methodology which combines the software Sesam and Abaqus to enable realistic hydrodynamic, structure and fatigue analyses of a container vessel in a harsh sea state. The software is needed in order to be able to choose a solver in the structure analysis to be either linear or nonlinear, depending on the cyclic elastic or plastic material response. Analyses of a case study of a 4400 TEU (twenty-foot equivalent unit) container vessel on the North Atlantic route are presented. A long-term fatigue analysis is performed in order to search for the fatigue-critical locations in the ship. A part of the side-shell structure was chosen for a detailed study comparing results from a linear and nonlinear finite element analysis for two significant wave heights: 6.0 and 7.5 m. The results show that for both of these wave heights cyclic plasticity occurs locally, but at a very low accumulation rate, which eventually results in elastic shakedown material response. Hence, the overall conclusion is that, in the studied location, a strain-based approach to fatigue is not necessary.

Containerships Fatigue life Finite element method Rough seas

543 ABSTRACTS

2015061469

Scaled model tests for the post-ultimate strength collapse behaviour of a ship's hull girder under whipping loads. Ships and Offshore Structures, v 10 n 1, 2015, pp 31-38 http://www.tandfonline.com/doi/full/10.1080/17445302.2013.870774#abstract Iijima, K., Suzaki, Y., Fujikubo, M. English

A series of experimental investigations on the post-ultimate strength collapse behaviour of a ship's hull girder under whipping loads are presented. It is a follow-up study of the authors based on numerical simulations. One of the important conclusions of the previous work is that given the same magnitude of the loads, the collapse extent is smaller for the loads with the shorter duration. For the validation, a scale model with a scale ratio 1/100, which follows a law of similitude in the ultimate bending strength as well as geometry, is employed in tank tests. The whipping loads are produced by dropping a mass object. The time history of the whipping loads is pre-adjusted by tuning the object mass, cushion material and dropping height. The hull girder bending moment with a time duration ranging 0.5–1.5 s in real scale, however, with the same magnitude, is applied to the hull girder. It was observed that the collapse extent was smaller for the loads with the shorter duration.

Collapse Hull girders Model tests Ultimate strength Whipping

2015061470

Fatigue strength of laser-welded thin-plate ship structures based on nominal and structural hot-spot stress approach. Ships and Offshore Structures, v 10 n 1, 2015, pp 39-44 http://www.tandfonline.com/doi/full/10.1080/17445302.2013.850208#abstract Fricke, W., Remes, H., Et al English

To improve the energy efficiency, the demand for new light-weight solutions has been increased significantly in the last decades. The weight reduction of the current ship structures is possible using thinner plates, that is, plate thickness between 3 and 4 mm. However, at present this is, in normal cases, not possible due to the 5 mm minimum plate thickness

requirement given by classification societies. This paper investigates the fatigue strength of thin-plated ship structures. In the European research project BESST – ‘Breakthrough in European Ship and Shipbuilding Technologies’ – the extensive fatigue test programme was carried out for butt- and fillet-welded specimens, which were manufactured by the arc, laser and laser-hybrid welding methods. The test programme also covered the different production quality and thus a large variation of misalignments was included. Fatigue test results were analysed using the nominal as well as the structural stress approach, where the actual geometry of the specimens was taken into account. The results show that the present design S–N curve with slope value of 3 is applicable to thin plates, but it is slightly non-conservative. The fatigue test results for thin plates show better agreement with the slope value of 5. For thin plates and slender ship structures, the secondary bending stress due to angular misalignment plays an important part and changes in a non-linear way with the applied tension load. Therefore, it is important to consider the plate straightening effect in structural stress analysis.

Fatigue strength Stress analysis Thin plates Welded joints

2015061471

Ultimate strength performance of bulk carriers with various corrosion additions. Ships and Offshore Structures, v 10 n 1, 2015, pp 59-78 http://www.tandfonline.com/doi/full/10.1080/17445302.2014.883957#abstract Kim, D.K., Kim, S.J., Et al English

In this study, various types of industry corrosion addition practices are investigated with regard to the ultimate strength performance of bulk carriers. Five types of corrosion additions, namely previously applied structural design rule, CSR (common structural rule), harmonised CSR, time-dependent corrosion wastage model, and new suggestion of corrosion addition by Union of Greece Shipowners, are considered. In the previous study, investigation on the ultimate strength performance of oil tankers associated with corrosion additions has been performed. In the similar way, four types of bulk carrier structures, namely 37 K (Handysize), 57 K (Supramax), 82 K (Kamsarmax), and 181 K (Capesize), are studied. The ultimate strength performance of hull girders and stiffened panels is

ABSTRACTS 544

examined through various corrosion additions used in industrial practices. The obtained results would be useful in understanding the corrosion addition effects in terms of ultimate strength of bulk carriers.

Bulk carriers Corrosion Ultimate strength

2015061472

Deformation behaviour of corroded plates subjected to blast loading. Ships and Offshore Structures, v 10 n 1, 2015, pp 79-93 http://www.tandfonline.com/doi/full/10.1080/17445302.2014.889371#abstract Eslami-Majd, A., Rahbar-Ranji, A. English

Numerical results for simply supported rectangular steel plates subjected to blast loading are presented. The effects of geometric and material non-linearities are considered. Finite element analysis with ABAQUS software is used to determine the deformation of corroded plates subjected to blast loads. The results for the cases of triangular pulse pressure representative of gas explosion overpressure on unstiffened plates are validated using published data. Thorough parametric studies are performed to study the effects of influential parameters, including aspect ratio of plates, degree of pitting and corrosion patterns. The results show that a reduction in the dynamic load carrying capacity of 8% can occur due to corrosion in plates with 50% degree of pitting. Also it is shown that the mid-point deflection increases with an increase in the applied impulse, and degree of pitting, however, decreases with increasing plate aspect ratio. Corrosion pattern has significant effect on reduction of load carrying capacity. Maximum reduction occurs when pits are concentrated at the centre of plate. The region between core diameter and the edges of the plate is less dangerous.

Dynamic response Explosions Finite element method Pitting corrosion

2015061473

Free vibration of stiffened open shells with variable radii of curvature using extended Kantorovich–Ritz method. Ships and Offshore Structures, v 10 n 1, 2015, pp 94-106 http://www.tandfonline.com/doi/full/10.1080/17445302.2014.889369#abstract Edalat, P., Khedmati, M.R., Guedes Soares, C. English

This study aims at free vibration of stiffened thin open-curved shells with parabolic curvatures. The shells have a curvature with variable radii in one direction. Different stiffening configurations that are usually applied in local ship structures, including un-stiffened, longitudinally stiffened, transversely stiffened, and orthogonally stiffened shells are studied. The energy relationship is derived by using the first-order shell theory as well as implementing the assumptions of global vibration mode. Natural frequencies and mode shapes related to the first five vibrational modes are extracted using extended Kantorovich–Ritz method (EKRM). The results of the EKRM were validated against those obtained by the Finite Element Method (FEM). The EKRM was found to have appropriate convergence and accuracy from the viewpoints of the natural frequencies and mode shapes.

Free vibration Stiffened shells

2015061474

Stochastic nonlinear fatigue crack growth predictions for simple specimens subject to representative ship structural loading sequences. International Journal of Fatigue, v 70, January 2015, pp 38-50 http://www.sciencedirect.com/science/article/pii/S0142112314002138 Hodapp, D.P., Collette, M.D., Troesch, A.W. English

Recent work by the authors investigated an extension of the finite element analysis of plasticity-induced crack closure to non-stationary, ship structural loading sequences by taking advantage of their inherent time-dependent nature in which the larger loading cycles tend to be clustered together. In doing so, first-order load interactions are presumed to arise from the random occurrence and severity of physical storms encountered by ships and offshore structures throughout their service lives. This material hysteresis is captured through a time-dependent crack “opening”

545 ABSTRACTS

level (Kop) which is based on the evolution of a rate-independent, incremental plasticity model simulating combined nonlinear kinematic and isotropic hardening. The result is a mechanistic rather than phenomenological numerical model requiring only experimentally measured fatigue crack growth rates under constant amplitude, cyclic loading (e.g., ASTM E647-13) and a full material constitutive model defined through experimental push–pull tests for the same material. This approach permits a consideration of material behaviours which are physically relevant to structural steels, yet necessarily omitted in the similar application of a strip-yield model. This paper generalizes the model originally proposed by the authors to now consider arbitrary storm model loading sequences taken from high-fidelity, time-domain seakeeping codes. To predict the fatigue fracture induced by variable amplitude stress records with upwards of 5×106 time-dependent cycles, a consistent modelling reduction is applied based on the Ordered Overall Range or racetrack counting method. The resultant crack growth behaviour is demonstrated to converge remarkably well for sufficiently small refined mesh sizes. Using this model, and by considering different arrangements of the same stress record, the importance of nonlinearities (i.e., those associated with ship response as well as material hysteresis) are emphasized.

Crack propagation Finite element method Loads (forces) Ship structures

4.2 PROPERTIES OF MATERIALS

2015061475

Strength assessment of a stiffened panel based on the modified stress curve approach. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 53, p 503 [8 p, 19 ref, 3 tab, 18 fig] http://www.crcpress.com/product/isbn/9781138027275 Tekgoz, M., Garbatov, Y., Guedes Soares, C. English

The objective of this work is to analyse the effect of the welding induced residual stresses on the ultimate strength of a stiffened panel by applying the modified stress-strain curve approach. Firstly, a thermal and mechanical nonlinear finite element analysis, based

on the moving heat source, is performed to estimate the residual welding induced stresses and distortions. Secondly, a structural nonlinear finite element analysis is carried out to estimate the stress-strain behaviour of stiffened panel and a modified material stress-strain curve is developed to account for the residual welding induced stresses. Thirdly, it is demonstrated how the new developed modified material stress-strain curve can be incorporated into the methodology, stipulated by the Common Structural Rules for analysing the ultimate strength of one bay stiffened panel. The ultimate strength of stiffened panel estimated based on the finite element analyses using the modified stress-strain curve, current Common Structural Rules and the one with the implemented correction for the residual stresses are compared and discussed.

Residual stress Stiffened plates Ultimate strength Welding

2015061476

Study on ultimate strength of ship plates with calculated weld-induced residual stress. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 54, p 513 [9 p, 16 ref, 4 tab, 22 fig] http://www.crcpress.com/product/isbn/9781138027275 Chen, B.Q., Guedes Soares, C. English

The objective of this work is to assess the importance of an accurate description of the distribution of residual stress for the assessment of the ultimate strength of rectangular plate and stiffened panels. The ultimate strength is assessed for the plates with calculated welding residual stress by nonlinear finite element analyses and it is compared with the results of the cases taking into account the idealized residual stresses as well as the residual stresses calculated by Common Structural Rules. It is concluded that the shape of the idealized residual stress distribution is very similar to the calculated one, although its size can only be determined from the calculated results. For the specific case studied here the idealized distribution results in 2% higher ultimate strength, while the IACS CSR underestimates the post collapse

ABSTRACTS 546

behaviour of the stiffened plate. The studies on the effects of initial geometrical distortion, boundary condition, element size and type, are also included.

Plates Residual stress Ultimate strength Weldments

2015061477

Analysis of butt-weld induced distortion accounting for the welding sequences and weld toe geometry. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 55, p 523 [10 p, 29 ref, 4 tab, 18 fig] http://www.crcpress.com/product/isbn/9781138027275 Hashemzadeh, M., Garbatov, Y. English

An analysis is made of butt-weld induced distortions of steel welded panels employing the finite element method, real measurements and existing empirical equations. The study is made for different welding sequences and weld toe geometry. A series of nonlinear, transient finite element analyses are performed. Different heating loads, defined as a moving heat source, simulate the welding process resulting from different welding sequences. The distortion after the welding is analysed to compare the estimated distortions employing finite method, existing empirical equations and real measurements.

Distortion Butt welds

2015061478

Numerical investigation of the thermal fields due to the welding sequences of butt-welds. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 56, p 533 [9 p, 24 ref, 3 tab, 19 fig] http://www.crcpress.com/product/isbn/9781138027275 Hashemzadeh, M., Garbatov, Y., Guedes Soares, C. English

Analysis is made of the butt-weld induced thermal

field and distortion of steel plates employing the finite element method and studying the effect of the welding sequences. A series of nonlinear, transient finite element analyses are performed. Different heating loads, defined as a moving heat sources, simulate the welding process resulting from different welding sequences. The thermal field at which the butt-weld is performed, and the resulting distortions after welding are also analysed.

Butt welds Distortion Temperature gradients Welding

2015061479

Compressive strength assessment of rectangular steel plates with a local dent or an opening. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 57, p 553 [9 p, 18 ref, 3 tab, 10 fig] http://www.crcpress.com/product/isbn/9781138027275 Saad-Eldeen, S., Garbatov, Y., Guedes Soares, C. English

The objective of this work is to compare the stress-strain behaviour of rectangular steel plates with an opening and with a dent, when a uniaxial compressive load is applied. Extensive nonlinear finite element analyses are performed, where the effect of several governing parameters on the stress-strain relation are analysed, including plate thickness, opening and dent sizes, shape and depth. The similarity in the structural response of a plate with a dent or an opening is identified. The pre and post buckling behaviour, stress-strain relationship and the ultimate strength lateral deformation are discussed and several conclusions are derived.

Compressive strength Plates Steel structures

547 ABSTRACTS

2015061480

Impact resistance of marine sandwich composites. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 63, p 607 [11 p, 26 ref, 4 tab, 20 fig] http://www.crcpress.com/product/isbn/9781138027275 Castilho, T., Sutherland, L.S., Guedes Soares, C. English

This work is motivated by the ever increasing range of applications of sandwich composite materials in the marine industry. A brief literature review is presented, followed by the manufacture and flexure, quasi-static and impact tests of a series of marine sandwich composites. Different core materials (PVC, Balsa Corecork NL10 and NL20) are used to produce a sandwich laminate, with E-glass/polyester skins. Drop-weight tests are performed until the failure of the second skin. PVC and NL20 specimens show predictability and repeatability of results, while NL10 present different failure modes and higher absorbed energy. Apart from the peak forces at the failure of both skins, that are around 1.5 times higher in the impact tests, the overall behaviour of the PVC, Balsa and NL20 specimens is well predicted by quasi-static tests. On the other hand, NL10 specimens’ behaviour change dramatically from static do impact test, increasing 3 times the absorbed energy. This work indicates that cork sandwich composites have potential in applications with impact requirements, with the downside of lower stiffness and higher weight.

Composite materials Impact strength Sandwich structures

2015061481

Analysis of the stress distribution in a composite to steel joint. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 64, p 619 [8 p, 13 ref, 7 tab, 19 fig] http://www.crcpress.com/product/isbn/9781138027275 Kharghani, N., Guedes Soares, C., Milat, A. English

A numerical analysis is made of a composite to steel joint in order to determine the stress distributions on

the joint as a function of the imposed bending and torsional loads. The steel component is a channel type of structure made of two plates that serve as external supports of the sandwich plate. The attachment of the steel joint to the structure is supported by a bracket. Finite element analysis is conducted with 3D models in order to determine the most highly stressed zones where failure can be expected. The cohesive properties have been modelled in order to simulate the adhesive failure steel-composite steel-core and core-composite. The results show load-deflection curves, stress distribution and de-bonding initiation points. Analysis of the results shows the most suitable values of the design parameters and the estimation of the maximum load that can be exerted on the specimen. These results serve as the basis to design test specimens and to plan an experimental program.

Composite materials Joints Numerical analysis Steel Stress concentration

2015061482

Finite element parametric study of a composite-to-steel-joint. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 65, p 627 [9 p, 28 ref, 2 tab, 24 fig] http://www.crcpress.com/product/isbn/9781138027275 Kotsidis, E.A., Kouloukouras, I.G., Tsouvalis, N.G. English

The use of metal-to-composite joints has recently extended into the marine field as a novel method of incorporating lightweight GRP structural parts (i.e. superstructures) to steel hulls. In this work, an adhesively bonded butt-joint, comprised of a double lap steel-GFRP joint and a GFRP sandwich composite part has been studied. In order to simulate the mechanical behaviour of the joint subjected to tensile and bending loading, a two-dimensional finite element model was developed. The numerical modelling encompassed cohesive elements so as to simulate the adhesive failure procedure. Various design parameters were examined in order to evaluate their effects on the joint load bearing capacity and stiffness. The analysis of the results showed that specific design parameters could fairly improve the

ABSTRACTS 548

joint’s strength and stiffness. Finally a specific joint design which met the desired characteristics is proposed.

Composite materials Joints Mechanical properties Steel

2015061483

Flexural testing of sandwich laminates for steel-composite joints. MARTECH 2014, 2nd International Conference on Maritime Technology and Engineering; 15-17 October 2014; Lisbon, Portugal. Published by CRC Press; ISBN 978-1-138-02727-5. Chapter 66, p 637 [7 p, 7 ref, 10 tab, 11 fig] http://www.crcpress.com/product/isbn/9781138027275 Sutherland, L.S., Alizadeh, F., Guedes Soares, C. English

The material properties of four laminates with different skin/core/production method are compared in order to identify their mechanical properties. In this study, 3-point flexural beam tests following the ASTM standard C393 are carried out on each of the four laminates and the results are compared. The main experimental conclusions were that laminates with thinner skins were susceptible to core crushing and that core properties did not always correspond with published manufacturer’s values. To validate a numerical procedure against experimental results an ANSYS FEA study to replicate the experimental results in terms of load-deflection curves and maximum load is carried out.

Flexural strength Laminates Sandwich structures

2015061484

Modelling approaches for reliability estimations of fibre-reinforced plastic laminates. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4542-4. Volume 4A: Structures, Safety and Reliability, Paper No. OMAE2014-23145 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911600 Sánchez-Heres, L.F., Ringsberg, J.W., Johnson, E. English

Numerous methodologies for estimating the reliability of composites have been published in the past few decades. This paper presents the experiences and findings by the authors regarding an assessment of different mechanical and probabilistic models for the calculation of reliability estimates of fibre-reinforced plastic laminates. The assessment was performed to determine the manner by which the models influence the reliability estimations. This knowledge is used to determine the most suitable combination of models for reliability-based design optimisation of marine structures made out of fibre-reinforced plastics. The assessment consists of a brief overview of a number of probabilistic and mechanical models as well as the computation of reliability estimates for a number of fibre-reinforced laminates through Monte Carlo simulations. Among some of the findings, it was found that the definition of matrix cracking and the choice of mechanical model (description of damage initiation and development) influence significantly the reliability estimations of fibre-reinforced plastic laminates.

Fibre composites Laminates Plastics Reliability

549 ABSTRACTS

2015061485

MOSAIC becoming ship shape. The Naval Architect, March 2015, p 18 [6 p, 10 fig] http://www.rina.org.uk/tna.html No author given English

After almost three years of intense research activity, MOSAIC, an EU-funded R&D project, is approaching its final stages of development. The project aims are to investigate two novel ideas; first, the introduction of high strength low alloyed steels in specific structural details, and the replacement of specific structural parts of the ship with composite materials.

Composite materials High strength steel Hull materials Low alloy steel Ship structures

2015061486

Shear and tensile failure of thin aluminium plates struck by cylindrical and spherical indenters. Ships and Offshore Structures, v 10 n 1, 2015, pp 45-58 http://www.tandfonline.com/doi/full/10.1080/17445302.2013.854029#abstract Liu, B., Vallavicencio, R., Guedes Soares, C. English

Experimental drop weight impact tests have been performed to examine the failure characteristics of small-scale clamped rectangular aluminium plates struck by a mass with cylindrical and spherical indenters. The laboratory results are compared with numerical simulations. Six plate specimens are impacted at the same kinetic energy in order to study the influence of the shape and the diameter of the indenter. The experiments are conducted using a fully instrumented impact testing machine. The obtained force–displacement responses show a good agreement with the simulations performed by the LS-DYNA finite element solver. The strain hardening of the material is defined using experimental data of quasi-static tensile tests and the critical failure strain is evaluated measuring the thickness and the width at fracture of the tensile test pieces. The results show that the impact response and the failure mode of the specimens are highly sensitive to the geometry of the

indenters. The failure modes are described by the matrix of the infinitesimal strain tensors and the shape of the deformation of the first failing element. In addition, the process of initiation and propagation of the material fracture is presented.

Aluminium Failure Impact tests Rectangular plates

4.3 CORROSION AND FOULING

2015061487

Spatial model for corrosion in ships and FPSOs. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4542-4. Volume 4A: Structures, Safety and Reliability, Paper No. OMAE2014-23062 [11 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911593 Luque, J., Hamann, R., Straub, D. English

Corrosion in ship structures is influenced by a variety of factors that are varying in time and space. Existing corrosion models used in practice only partially address the spatial variability of the corrosion process. Typical estimations of corrosion parameters are based on averaging measurements over structural elements from different ships and operational conditions, without considering the variability among and within the elements. However, this variability is important when determining the necessary inspection coverage and it may influence the reliability of the ship structure. The authors develop a probabilistic spatio-temporal corrosion model based on a hierarchical approach, which represents the spatial variability of the corrosion process. The model includes the hierarchical levels vessel – compartment – frame – structural element – plate element. At all levels, variables representing common influencing factors are introduced. Moreover, at the lowest level, which is the one of the plate element, the corrosion process is modelled as a spatial random field. For illustrative purposes, the model is trained through Bayesian analysis with measurement data from a group of tankers. In this application it is found that

ABSTRACTS 550

there is significant spatial dependence among corrosion processes in different parts of the ships, which the proposed hierarchical model can capture. Finally, it is demonstrated how this spatial dependence can be exploited when making inference on the future condition of the ships.

Corrosion Probabilistic methods Ship structures

2015061488

Performance of marine and offshore paint systems: Correlation of accelerated corrosion tests and field exposure on operating ships. Materials and Corrosion, v 66 n 3, March 2015, pp 215-225 http://onlinelibrary.wiley.com/doi/10.1002/maco.201307340/abstract LeBozec, N., Thierry, D., Et al English

Corrosion resistance is an important property requirement for marine paint systems used in naval industry such as for ship's topsides and superstructures, which obliges testing the coating performance in order to make a durable selection of the paint systems. This can be achieved by performing laboratory accelerated corrosion tests recommended for C5M corrosivity class (in particular the standard neutral salt spray test ISO 9227 or the cyclic corrosion test ISO 20340-Annex A) which give results in a rather short delay (up to 6 months) compared to field exposures in marine atmospheres (several years). It is however well known that these tests may not be fully representative of real ship environmental conditions. The aims of the present study were thus to compare and estimate the correlation of various accelerated corrosion tests including standardized tests (ISO 9227, ISO 20340, ISO 16701) and newly developed test conditions to field exposures on worldwide operating ships (container carrier vessel and oceanographic ship) and on conventional static marine atmospheric sites (C5M). Fifteen different marine paint systems commonly used for offshore and naval application were selected for the study. From the results, the exposure conditions on the container vessel were the most aggressive ones compared to static exposures

after 2 years. The best correlation to such field exposure was observed using the cyclic test ISO 16701 with a deviation inferior to 25%, an acceleration factor of 4 and comparable corrosion aspect. If all testing conditions involving NaCl 5 wt% (including ISO 20340) showed a superior acceleration factor (e.g., about 12), a larger deviation (50%) was however found indicating that these tests did not accelerate the corrosion degradation of the paint systems similarly to field exposures. In addition, conditions for an optimisation of ISO 20340 annex A test were found.

Coatings Corrosion resistance Corrosion tests

2015061489

Influence of Stress-corrosion Fractures on Potential of Ship-building Metals in the Sea Water. Procedia Engineering, v 100, 2015, pp 1068-1074 http://www.sciencedirect.com/science/article/pii/S1877705815004956 Kramar, V., Dushko, V., Et al English

The installation for new formed surface creation of metal has been developed. Experiments were carried out in model solutions of NaCl on samples of various shipbuilding metals. Shipbuilding metal potentials without oxide film in the marine and ocean water have been obtained. The results show how much the steel potential value was critical “inside” the crack under corrosion-mechanical and fatigue destruction. The obtained results show that the electrochemical corrosion account is possible at application of high-tensile steels, which used in dynamically loaded constructions in corrosion environments. Investigation of the steel protection parameters in relation to specific products and service conditions may allow to control the corrosion fatigue properties of metals and predict these characteristics in the future.

Cathodic protection Fracture Hull materials Steel Stress corrosion

551 ABSTRACTS

5 NAVAL VESSELS AND DEFENCE TECHNOLOGY

2015061490

Fire modelling and event tree analysis for naval platform fire incidents. International Conference on Fire at Sea, 26-27 March 2014; London, UK. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Gamble, G., Suendermann, B., Et al English

Computational Fluid Dynamics modelling is utilised to predict the behaviour and spread of fire in a multi-storey compartment and was validated experimentally. Furthermore, event tree analysis was utilised to evaluate the consequences of crew actions and the ability of fire safety systems to control fires onboard naval ships.

Computational fluid dynamics Mathematical logic Naval vessels Shipboard fires

2015061491

Analysis of the German Navy stability standard BV 1030 with respect to operability in heavy weather. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4550-9. Volume 8A: Ocean Engineering, Paper No. OMAE2014-23390 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912044 Krüger, S., Hatecke, H., Et al English

The stability standard of the German Navy - the BV 1030 - was developed in the mid-sixties of the last century in close cooperation with the German Navy Authorities (now BAIINBw) and the University of Hamburg. Other than the stability standards used for commercial shipping, the BV 1030 is based on righting and heeling lever balances for each individual loading condition of each individual ship. Different types of heeling moments have to be assumed in several combinations and they have to be balanced against the righting levers of the ship. Not only the still water stability curve is subject to this lever balance, but also wave crest and wave trough

situations are subject to the stability analysis. The BV 1030 stability standard further requires a minimum stability if the ship is on the wave crest. Since this stability standard is in force, the German Navy never experienced a stability accident. The development of new hull forms with the focus on fuel efficiency has widely brought up new problems in heavy weather, for example the vulnerability for parametric rolling. It was therefore of interest for the German Authorities (BAIIN) whether the existing stability standard has sufficient safety to cover also these phenomena connected to more modern hull forms. Therefore an analysis was carried out in close cooperation between BAIINBw, MARS and TUHH where the operability of several ships of the German Navy was analysed with numerical seakeeping computations. The nonlinear seakeeping code E4ROLLS was used which allows the computation of time series of the ship motions in irregular, short crested seas. From these computations, operational limits could be derived, or, vice versa, the required stability to guarantee a certain operability. The results showed that the concept of the German BV 1030 stability standard provides a significantly higher safety level compared to IMO standard for commercial ships. The results did also show that for modern hull forms, some adjustments to the existing safety standard were found to be useful to better cope with righting arm fluctuations in longitudinal waves.

Heavy weather Naval vessels Stability Standards

2015061492

Key role for Indian ISVs protecting offshore infrastructure. Warship Technology, March 2015, p 26 [2 p, 2 fig] http://www.rina.org.uk/wt.html No author given English

The Indian Navy continues to induct small craft into service to ensure coastal security and defend infrastructure in offshore areas. Among the latest additions to this growing fleet are 23 Immediate Support Vessels (ISV) built of composites that have been procured by India’s Oil and Natural Gas Company (ONGC) at a cost of approximately US$54 million. They are operated by the Indian Navy and used for surveillance and protection of offshore oil and gas installations near Mumbai and elsewhere in India’s so called offshore development areas (ODA). The Craftway-built ISVs have a length of 23.1m,

ABSTRACTS 552

beam of 5.6m, draught of about 1m and a full-load displacement of 47tonnes. Built entirely of composites DIAB Divinycell H80 and H60 core materials to RINA classification society high speed craft rules with C+HSC - C - MON notation for special service craft Craftway claims they are the largest fibre-reinforced plastic boats to be built completely in India. A general arrangement drawing is included in this article.

Naval vessels Patrol craft Small craft

6 MISCELLANEOUS

2015061493

Problems encountered by the students in the implementation of outcomes-based education at the Maritime Academy of Asia and the Pacific. International Conference on the Education & Professional Development of Engineers in the Marine Industry, 15-16 April 2014; Busan, Korea. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Punongbayan, A.R. English

With the introduction of Outcomes-Based Education (OBE) in the Philippines, a number of educational institutions implemented OBE as early as 2009 but there is a dearth of reports on the problems met by either the teacher or students in the schools where OBE was initially implemented. The purpose of this study was to gather and document the problems encountered by the Maritime Academy of Asia and the Pacific during the first implementation of OB in the first semester of school year 2013-2014. In this descriptive research, 702 students taking Bachelor of Science in Marine Transportation and Bachelor of Science in Marine Engineering identified the problems they encountered as assessment, teaching, technology, time teach and lesson pacing-related problems given in a questionnaire. Furthermore, the data analysis showed that students during the initial OBE implementation agreed or strongly agreed on the following: better for the instructor to take over the report; the students are not certain which part of the

students’ report will be included in the teacher prepared examination if there are any; students’ access time to computers is limited; they (students) do not own their time; and teachers just watch and listen during the class. The researcher recommends that these problems be looked into for necessary adjustments or policy modifications. Problems must not deter OBE implementers; rather, they should become openings for opportunities to improve the quality of education.

Maritime education and training

2015061494

Academic curricula based on industrial requisites. International Conference on the Education & Professional Development of Engineers in the Marine Industry, 15-16 April 2014; Busan, Korea. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Guha, S. English

The major fields in the maritime sector are marine engineering, offshore engineering, dredging- harbouring and ship design. In relation to these, employments are mainly found in shipyards, shipping companies, ports etc. So if there are graduate and post graduate courses specifically in these fields, it would not be problem to look for employments for e.g. B.Tech in marine engineering, B.Tech in naval architecture or dredging and harbouring. Previously it was a trend to divert to the marine sector after graduating in core engineering branches, but now with awareness in this field institutes are offering the above mentioned courses and students are also showing interest in taking up these courses. Now, the institutes should mould their curriculum in such a way that students after passing out become well-built professionals to be readily accepted in the marine sector. The institutes should have: To gain practical knowledge, compulsory training courses should be there in marine companies, shipyards and ports for all students along with proper facilities and stipends. But it should be initiative of the institute. In corporate sectors managerial posts are designated to a graduate employee from an engineering background so institutes should have

553 ABSTRACTS

compulsory management courses in the syllabi. Workshop technological labs with welding equipment, lathe machines should be there for training students. Students should be encouraged to construct small scale models. Compulsory software training to get employment in marine design sectors. Free visit to shipyards and ports. These in brief are the basic initiatives or modifications the institutions should make in their academic curricula to befit industrial requisites.

Marine engineering Maritime education and training Maritime industries Naval architecture Offshore engineering

2015061495

Workshop and laboratory practices in naval architecture and shipbuilding academic curriculum: teaching enhancement using in-house models and shipyard internship programmes. International Conference on the Education & Professional Development of Engineers in the Marine Industry, 15-16 April 2014; Busan, Korea. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Sivaprasad, K., Asok, A., Vijayn, V. English

Naval architecture and shipbuilding is one of the oldest branches of engineering and it has contributed to the development of human civilization substantially. Due to its interdisciplinary and massive nature of the practical outcome, i.e., ship as a product, there are some practical difficulties in implementing workshop and laboratory practices undertaken as part of the undergraduate academic curriculum. This paper proposes solutions to these issues using enhanced teaching methods with the help of ship models and mock-up and effective utilization of internship programmes attached to ship and boat yards. Case studies associated with the proposed study models undertaken in the Department of Ship Technlogy, Cochin University of Science and Technology, India are also presented.

Maritime education and training Shipbuilding

2015061496

Use of virtual learning environment and cloud computing systems in maritime education and training: issues and challenges. International Conference on the Education & Professional Development of Engineers in the Marine Industry, 15-16 April 2014; Busan, Korea. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Muhammad, I.F.B., Yutuc, I.F. English

Among the many innovative e-learning technologies in use today which are intended for teaching, learning enhancement and convenience - the virtual learning environment (VLE) and cloud computing system (CCS) may be worthy of serious consideration in developing a new andragogical framework in Maritime Education and Training (MET). With the maritime industry's mindset focused on competency development of shipboard personnel through practical training, the value of such systems may not be fully understood and may be overshadowed by the fact that it may be provided free of charge and thus thought to be of little value. But considering its many features and available applications, it may indeed be an effective tool to help achieve the numerous goals and meet the expected learning outcomes in MET. It also brings the advantage of exposing the students to a higher level of computing skills that can be transferred directly to new technologies used in the maritime and shipping industry plus the benefit of providing instruction in a flexible manner with varying time and location autonomies. This paper presented the barriers associated with the implementation on the use of VLE and CCS in MET and the suggested solutions.

Maritime education and training

2015061497

The E-Lab project at UCL. International Conference on the Education & Professional Development of Engineers in the Marine Industry, 15-16 April 2014; Busan, Korea. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Muk-Pavic, E., Collins, L. English

The current emphasis in education is the use of e-learning and on line tools. This provides an additional teaching environment and the opportunity to increase the variety of activities used to achieve learning outcomes. With this in mind, a new learning resource

ABSTRACTS 554

called 'E-Lab' was developed and introduced to the ship hydrodynamics module of the Naval Architecture MSc Programme at UCL. 'E-Lab' stands for 'Electronic-Laboratory' as it uses web- based material to educate students on, and guide them through, a practical experiment using UCL's Towing Tank Facilities. The primary aim was two-fold: First, to investigate the advantages and practicality of using E-delivery and specifically, how UCL's online resource 'Moodle' could be better utilised. Second, it was an opportunity to improve practical knowledge and experience, something that has seen to be lacking on current postgraduate courses. As a secondary aim, using e-delivery for a practical experiment introduced a social constructivist and situative learning perspective, where students develop their identity working in a group and actively learn new ides through collaborative activities and dialogue. Although the Moodle site steers student learning, the experience for the students is one of self-learning and learning together, which is highly conducive to group work and open discussions of the topic. This paper outlines the format of E-Lab, the aims and objectives of its implementation, discusses the changes in the approach to learning and teaching that such resources may bring, before presenting the results of the E-lab trial and assessing the successes and failures of the project.

Maritime education and training

2015061498

Teaching seakeeping for ships and offshore structures: a delicate balance. International Conference on the Education & Professional Development of Engineers in the Marine Industry, 15-16 April 2014; Busan, Korea. Organised by RINA, London, UK. http://www.rina.org.uk/publications.html Dev, A.K. English

Seakeeping is traditionally taught for naval architecture using mainly ships as examples. Many books are also available in a similar way citing ships as examples. However, in order to cater for students in offshore or ocean engineering, a paradigm shift is inevitable. The author teaches the seakeeping part of the module Marine Dynamics for Stage 2 students of both streams: naval architecture and offshore engineering. The available hours are limited, and within this span of time the students of both streams have to be taught basic seakeeping aspects citing examples of both ships and offshore structures. This is rather a challenge. As the same group of students

study another module: Marine and Offshore Mechanics, a delicate balance needs to be maintained so that both groups of students can have an equal understanding of the subsequent module with ease and comfort. The author has now taught seakeeping for the last 5 years and has found that most of the students finally manage to understand the module quite well. The author is of the opinion that teaching and learning in Stage 2 has been the root of the final success.

Maritime education and training Seakeeping

2015061499

Modal split in offshore supply network under the objective of emissions minimization. Transportation Research Part D: Transport and Environment, v 35, March 2015, pp 160-174 http://www.sciencedirect.com/science/article/pii/S1361920914001813 Norlund, E.K., Gribkovskaia, I. English

The authors study modal split under the objective of emissions minimization in the transportation of cargo from centralized vendors in the oil and gas industry to decentralized supply bases on the Norwegian coast. The supply network includes direct road transport and a sea route along the coast. To gain insight into modal split decisions between road and sea transport from the shipper’s perspective multi-period mixed integer optimisation models are formulated. Particularly the models give possibilities to examine how weekly demand patterns at supply bases, cargo commitments to sea transport, storage possibilities at supply bases, and shipper’s responsibility for a certain share of vessel capacity may affect the emissions and the modal split. Experiments on real data from an oil and gas company operating offshore show that the size of the share of vessel capacity and the possibility for storage at supply bases are the major determinants for a larger shift to environmentally friendly sea transport. The models can be used as means for making decisions regarding how a shipper can commit to sea transport to achieve lower emissions.

Emissions Offshore industries Optimisation Transportation modes

555 ABSTRACTS

2015061500

An empirical study of fleet expansion and growth of ship size in container liner shipping. International Journal of Production Economics, v 159, January 2015, pp 241-253 http://www.sciencedirect.com/science/article/pii/S0925527314002941 Tran, N.K., Haasis, H-D. English

The world fleet capacity has been continuously enlarged in container liner shipping. In line with the enlargement, new ship generations have been launched, especially since the 1990s. The paper concentrates on the two major issues of capacity expansion and growth of ship size in the industry. Multiple regression models are built to measure the effects of fleet capacity and ship size as well as slot utilisation level, market freight rate and oil price on revenue and cost of shipping lines in the period 1997–2012. Investing in new capacity will lead to higher total revenue of operators whereas lower unit revenue. Its positive effect on total and unit cost can be noted. No statistical evidence is found to indicate the relationship between ship size and financial indicators. Additionally, it is possible to evaluate positive influence of slot utilisation level and market freight rate, and negative influence of oil price on financial results of liner carriers.

Containerships Economies of scale Liner shipping Merchant fleets Ship size

ABSTRACTS 556

Author Name Abstract No.

Abbasnia, A. 2015061435 Abdussamie, N. 2015061432 Acanfora, M. 2015061449 Ahlers, K. 2015061320 Ahmed, Y.M. 2015061371 Ahola, M. 2015061260 Akamatsu, T. 2015061332 Alessandri, A. 2015061390 Alizadeh, F. 2015061483 Alkan, A.D. 2015061389 Almeida, S. 2015061310 Altosole, M. 2015061283 2015061364 Amaral Amange, D. do 2015061465 Ando, Y. 2015061267 Andreeva, N. 2015061351 Andrews, D. 2015061254 Aoyama, Y. 2015061363 Artyszuk, J. 2015061269 Ashrafizaadeh, M. 2015061355 Asok, A. 2015061495 Athisakul, C. 2015061445 Atlar, M. 2015061303 Azadbakht, M. 2015061423 Badino, A. 2015061451 Bakkay, B.E. 2015061349 Bal, H. 2015061366 Bal, S. 2015061303 2015061360 2015061361 Beckett, A. 2015061325 Belloli, M. 2015061415 Benvenuto, G. 2015061284 Bergström, M. 2015061348 Bertram, V. 2015061302 2015061337 Beşik, M. 2015061288 Bigot, F. 2015061394 Bitner-Gregersen, E.M. 2015061275 Bøckmann, E. 2015061346 Bos, A.J. 2015061336 Bos, R.W. 2015061376 Bosch, F.A.J. van den 2015061297 Bose, N. 2015061460 Brodtkorb, A.H. 2015061342 Buczkowski, RF. 2015061450 Çakıcı, F. 2015061389 Campora, U. 2015061284 Cao, J. 2015061300 Carrica, P. M. 2015061398 Castilho, T. 2015061480 Ćatipović, I. 2015061407 Çelik, F. 2015061361 2015061367

Chacaltana, J.T.A. 2015061308 Chakrabarti, P. 2015061455 Chatzitolios, K. 2015061257 Chaudhury, G. 2015061440 Chauhan, A. 2015061255 Chauhan, U. 2015061255 Chawan, A. 2015061455 Chen, B.Q. 2015061476 Chen, C-h. 2015061270 Chen, Y. 2015061412 2015061414 Chen, Y-S. 2015061399 Cheng, Y. 2015061420 Cherneva, Z. 2015061351 Cho, D-S. 2015061456 Choi, B-k. 2015061253 Choi, T-M. 2015061456 Chucheepsakul, S. 2015061445 Ciortan, C. 2015061371 Coache, S. 2015061368 Coche, E. 2015061349 Collette, M.D. 2015061453 2015061474 Collins, L. 2015061497 Coppola, T. 2015061449 Ćorak, M. 2015061317 2015061454 2015061458 2015061467 Coutinho, A.L.G.A. 2015061424 Cozijn, J.L. 2015061379 Cuellar, W.H. 2015061305 Datta, R. 2015061403 Dausendschön, K. 2015061347 Degiuli, N. 2015061407 Dekker, J.A. 2015061426 Demirel, H. 2015061288 Deng, Y. 2015061391 Dermen, O. 2015061327 Dev, A.K. 2015061498 Dijk, R. van 2015061313 Dimopoulos, G.G. 2015061287 Dinwoodie, J. 2015061298 Dobashi, J. 2015061396 2015061397 Doğrul, A. 2015061367 Dombre, E. 2015061352 Dong, Y. 2015061328 Donnarumma, S. 2015061390 Dostal, L. 2015061393 Duan, W-y. 2015061399 Dubbioso, G. 2015061354 Dushko, V. 2015061489 Dutta, A. 2015061403

AUTHOR INDEX A-1

Edalat, P. 2015061473 Ehlers, S. 2015061348 2015061350 Ekinci, S. 2015061367 Elias, R.N. 2015061424 Erikstad, S.O. 2015061350 Erselcan, I.O. 2015061386 Ertinaz, F. 2015061362 Esfahan, R.K. 2015061355 Eslami-Majd, A. 2015061472 Estefen, S.F. 2015061465 Ezequiel, M.J. 2015061398 Ezoji, M. 2015061410 Fernandes, A.C. 2015061392 Ferrari, V. 2015061408 Figari, M. 2015061364 Fitzgerald, M. 2015061254 Forehand, D. 2015061416 Forsth, M. 2015061326 Fortaleza, E. 2015061305 Fortes, C.J.E.M. 2015061409 Frangopol, D.M. 2015061328 Fricke, W. 2015061447 2015061470 Fujii, R. 2015061268 Fujikubo, M. 2015061469 Fujiwara, T. 2015061433 Furuichi, M. 2015061338 Gadelho, J.F.M. 2015061427 Gaggero, S. 2015061369 Gaggero, T. 2015061369 Gamble, G. 2015061490 Gang, C. 2015061263 Garbatov, Y. 2015061452 2015061475 2015061477 2015061478 2015061479 Georgiev, A. 2015061340 Ghaisi, M. 2015061435 Gharabaghi, A.R.M. 2015061410 Giappino, S. 2015061415 Ginnis, A.I. 2015061276 Goerlandt, F. 2015061343 Gol-Zaroudi, H. 2015061410 Görener, N. 2015061366 Greening, D. 2015061259 Grenestedt, J.L. 2015061444 Gribkovskaia, I. 2015061499 Gualeni, P. 2015061271 Gucma, S. 2015061269 Guedes Soares, C. 2015061307 2015061309 2015061310 2015061311 2015061351

Guedes Soares, C. 2015061380 2015061400 2015061401 2015061402 2015061404 2015061406 2015061408 2015061435 2015061436 2015061437 2015061454 2015061458 2015061467 2015061473 2015061475 2015061476 2015061478 2015061479 2015061480 2015061481 2015061483 2015061486 Guha, S. 2015061494 Guimarães, H.B. 2015061392 Guo, Y. 2015061301 Haasis, H-D. 2015061500 Hallmann, R. 2015061379 Hamada, K. 2015061268 Hamann, R. 2015061487 Hane, F. 2015061395 Harmsen, E. 2015061313 Harris, J.C. 2015061352 Hashemzadeh, M. 2015061477 2015061478 Hashizume, Y. 2015061457 Hatecke, H. 2015061491 He, G. 2015061439 Hinok, T. 2015061264 Hinostroza, M.A. 2015061380 Hitoi, Y. 2015061280 Hodapp, D.P. 2015061474 Holland, C. 2015061322 Hollen, R.M.A. 2015061297 Hooijmans, P.M. 2015061259 Hu, Z. 2015061462 Huisman, T.J. 2015061376 Ibekwe, A.U. 2015061466 Iida, T. 2015061439 Iijima, K. 2015061469 Ikeda, Y. 2015061261 2015061363 2015061383 Ikonen, T. 2015061459 Im, H-I. 2015061253 Incertis, D. 2015061296 Iwanowski, B. 2015061429

A-2 AUTHOR INDEX

Jafaryeganeh, H. 2015061402 Jensen, J. J. 2015061434 Jhingran, V. 2015061417 Ji, Z. 2015061263 Jiang, X. 2015061464 Johnson, E. 2015061484 Kajiwara, H. 2015061280 Kakalis, N.M.P. 2015061287 Kaleff, P. 2015061294 Kaminski, M.L. 2015061464 Karakaş, A. 2015061282 Karhunen, J. 2015061459 Karmakar, D. 2015061437 Karunakaran, D. 2015061314 Kashiwagi, M. 2015061439 Katalinić, M. 2015061317 Katayama, T. 2015061384 Khalifa, J. 2015061430 Kharghani, N. 2015061481 Khedmati, M.R. 2015061473 Kim, D.K. 2015061471 Kim, J. 2015061334 Kim, K.S. 2015061431 Kim, M.H. 2015061431 2015061446 Kim, S. 2015061446 Kim, S.J. 2015061471 Kim, Y. 2015061358 2015061377 Kimura, H. 2015061267 Kinaci, Ö.K. 2015061360 Kishev, R. 2015061340 2015061425 Klaycham, K. 2015061445 Kostas, K.V. 2015061276 Kotsidis, E.A. 2015061482 Kouloukouras, I.G. 2015061482 Kramar, V. 2015061489 Krause, M. 2015061359 Kreuzer, E. 2015061393 Krüger, S. 2015061262 2015061491 Kükner, A. 2015061386 Kumagai, I. 2015061378 Kuttenkeuler, J. 2015061335 Kuznetsov, A. 2015061298 Kvillum, T. 2015061272 Kvitrud, A. 2015061306 Laranjinha, M. 2015061272 Larsen, U. 2015061286 Lasche, C. 2015061318 Laurens, J.-M. 2015061368 Laviola, M. 2015061283 2015061284 Lavrov, A. 2015061401 LeBozec, N. 2015061488

Lee, J. 2015061377 Lee, J-F. 2015061419 Lee, S.B. 2015061374 Lee, S.E. 2015061274 Lee, S-H. 2015061273 Lee, Y-G. 2015061273 Lee, Y.M. 2015061374 Lefranc, M. 2015061429 Li, H. 2015061373 Li, Z. 2015061468 Ligteringen, H. 2015061329 Lindstrom, J. 2015061326 Liu, B. 2015061486 Liu, C-C. 2015061419 Liu, K. 2015061461 Liu, P. 2015061460 Lofti, P. 2015061355 López, A. 2015061315 Lu, J. 2015061331 Lübcke, A. 2015061262 Luo, W. 2015061380 Luque, J. 2015061487 Lv, J. 2015061444 Macpherson, G.B. 2015061324 Maeda, K. 2015061433 Magica, R. 2015061260 Maljaars, P.J. 2015061426 Mansour, A.M. 2015061304 Mao, W. 2015061463 Marinheiro, J. 2015061312 Martins, M.R. 2015061295 Martio, J. 2015061357 Masuda, M. 2015061289 Matsuda, A. 2015061388 Mauro, S. 2015061354 McNatt, J.C. 2015061416 Medeiros, J.S. de 2015061392 Meij, K.H van 2015061259 Michel, R. 2015061336 Milat, A. 2015061481 Minami, K. 2015061289 Minoura, M. 2015061345 Miyake, S. 2015061345 Mohapatra, S.C. 2015061307 Mon, A.A. 2015061264 Montewka, J. 2015061343 Moreira, R.M. 2015061308 Mori, S. 2015061266 Moustafa, M.M. 2015061370 Mudronja, L. 2015061405 Muhammad, I.F.B. 2015061496 Muk-Pavic, E. 2015061497 Murai, Y. 2015061378 Myrhaug, D. 2015061346 Nabergoj, R. 2015061382 Nabergoj, T. 2015061258

AUTHOR INDEX A-3

Nam, B-W. 2015061358 Nguyen, T. van 2015061383 Nichita, C. 2015061258 Nikolopoulos, L. 2015061256 Nikolov, G. 2015061425 Norlund, E.K. 2015061499 Núñez, L.R. 2015061315 2015061316 Oberlies, R. 2015061430 Ochoterena, R. 2015061326 Ogeman, V. 2015061463 Ölmez, H. 2015061385 Orihara, H. 2015061341 Ortolani, F. 2015061354 Otani, I. 2015061289 Otsuka, N. 2015061338 Ou, J. 2015061420 Ouchi, K. 2015061442 Özden, Y.A. 2015061361 Paik, J.K. 2015061274 Panciroli, R. 2015061418 Papanikolaou, A. 2015061256 Park, D-M. 2015061377 Park, J-C. 2015061431 Park, Y.H. 2015061448 Parunov, J. 2015061317 2015061405 2015061454 2015061458 2015061467 Peltokorpi, O. 2015061459 Peşman, E. 2015061385 Pestana, M.A. 2015061295 Piastra, F. 2015061364 Pierobon, L. 2015061286 Pinheiro, L. 2015061409 Pinkowski, J. 2015061318 Porfiri, M. 2015061418 Prpić-Oršić, J. 2015061382 Pu. Y.C. 2015061466 Puig, M. 2015061333 Punongbayan, A.R. 2015061493 Radonjic, A. 2015061339 Rahbar-Ranji, A. 2015061472 Rao, Z. 2015061417 Rathour, S.S. 2015061332 Remes, H. 2015061470 Ren, H-l. 2015061373 Ribeiro e Silva, S. 2015061404 Ringsberg, J.W. 2015061463 2015061468 2015061484 Riska, K. 2015061349 Rizzuto, E. 2015061279 2015061451 Rodrigues, J.M. 2015061402

Rodrigues, J.M. 2015061427 Rodrigues, S.R.A. 2015061309 Roland, F. 2015061359 Rosa-Santos, P. 2015061312 Rosén, A. 2015061335 Rusu, E. 2015061311 Rusu, L. 2015061310 Saad-Eldeen, S. 2015061479 Saito, M. 2015061433 Sakai, M. 2015061388 Sánchez-aja, A. 2015061357 Sánchez-Heres, L.F. 2015061484 Santos Rizzo, N.A. dos 2015061465 Santos, J.A. 2015061309 Schier, H. 2015061320 Seah, R. 2015061394 Sengupta, D. 2015061403 Senjanovic, I. 2015061443 Seong, E. 2015061387 Shams, A. 2015061418 Shen, Z. 2015061441 Shi, Y. 2015061300 Shingo, S. 2015061265 Sivaprasad, K. 2015061495 Skoglund, L. 2015061335 Skrunes, O.V. 2015061314 Slater, D.J. 2015061299 Søfteland, T.E. 2015061314 Sonechko, D. 2015061258 Sørensen, A.J. 2015061342 Spigno, M. 2015061271 Steen, S. 2015061346 Stefanatos, I.C. 2015061287 Stefani, S. 2015061321 Stern, F. 2015061353 Strasser, G. 2015061356 Straub, D. 2015061487 Succio, D. 2015061279 Suendermann, B. 2015061490 Sukas, Ö.F. 2015061360 2015061389 Sun, B. 2015061462 Sunaryo, S. 2015061319 Sutherland, L.S. 2015061480 2015061483 Sutulo, S. 2015061400 2015061408 Suzaki, Y. 2015061469 Suzuki, K. 2015061264 Svensson, B. 2015061285 Taczała, M. 2015061450 Takagi, K. 2015061356 Takahashi, Y. 2015061378 Tan, L.B. 2015061412 Tanaka, Y. 2015061457 Tang, W-y. 2015061461

A-4 AUTHOR INDEX

Tapia, M. 2015061294 Tarbiat, S. 2015061401 Taylan, M. 2015061385 Taylor, G. R. 2015061372 Teel, A.R. 2015061342 Tekgoz, M. 2015061475 Terrill, E. J. 2015061372 Thad, M. 2015061398 Thierry, D. 2015061488 Thomas, G. 2015061432 Tomić, M. 2015061443 Tran, N.K. 2015061500 Troesch, A.W. 2015061474 Tsouvalis, N.G. 2015061482 Tsukada, Y. 2015061365 2015061411 Tu, L-F. 2015061419 Twigt, M. 2015061322 Ueno, M. 2015061365 2015061411 Umeda, J. 2015061384 Umeda, N. 2015061388 Uşar, D. 2015061303 Uzunoglu, E. 2015061404 Valčić, M. 2015061382 Vallavicencio, R. 2015061486 Vandiver, J.K. 2015061417 Vanem, E. 2015061275 Veitch, B. 2015061460 Venugopal, V. 2015061416 Vestbøstad, T. 2015061429 Vidan, P. 2015061405 Vijayn, V. 2015061495 Vladimir, N. 2015061456 Volberda, H.W. 2015061297 Vukadinovic, K. 2015061339 Wan, D. 2015061441 Wang, J. 2015061330 Wang, S. 2015061436 2015061437 Wang, X.K. 2015061413 Wang, Z. 2015061353 Wighus, R. 2015061323 Woodridge, C. 2015061333 Wu, C. 2015061304 Wyse, S.G. 2015061324 Xi, P. 2015061375 Xiao, F. 2015061329 2015061438 Xiao, L. 2015061391 Xie, B. 2015061428 Xin, S. 2015061266 Xiong, Y. 2015061375 Xue, M-A. 2015061422 Yan, S. 2015061331 Yang, H. 2015061331

Yang, H. 2015061438 Yang, H.M. 2015061448 Yang, J. 2015061391 Yang, K-K. 2015061358 Yang, Y. 2015061421 Yang, Z. 2015061330 Yao, Z-l. 2015061270 Yasukawa, H. 2015061381 Yehia, W. 2015061370 Yeter, B. 2015061452 Yiğit, K. 2015061282 Yim, S.C. 2015061423 Yoon, H.K. 2015061387 Yoshida, H. 2015061341 Yoshimura,Y. 2015061381 Yraola, A.M. 2015061316 Yu, H. 2015061464 Yu, J-W. 2015061273 Yu, L. 2015061422 Yun, K. 2015061334 Yutuc, I.F. 2015061496 Zandwijk, K. van 2015061313 Zeng, H. 2015061301 Zhai, G. 2015061420 Zhang, H.D. 2015061406 Zhang, J. 2015061414 Zhang, J.-X. 2015061413 Zhang, Y. 2015061421 Zhao, W. 2015061441 Zheng, J. 2015061422 Zhou, X. 2015061400 Zhu, J. 2015061453 Zhu, X. 2015061428

AUTHOR INDEX A-5

Ship/Structure Name Abstract No.

Leiftur 2015061252 Stena Impression 2015061251 Thorbjörg 2015061252

SHIP AND STRUCTURE NAME INDEX S-1

Keyword Abstract No.

Accommodation spaces 2015061451 Acoustics 2015061448 Added resistance in waves 2015061358 2015061363 2015061377 Adriatic Sea 2015061317 Ageing ships 2015061294 Air 2015061442 Air entrainment 2015061372 Air lubrication 2015061290 Aluminium 2015061486 Anchors 2015061289 Antirolling tanks 2015061385 Arctic environment 2015061323 Arctic marine transportation 2015061348 Arctic regions 2015061338 2015061349 2015061350 Artificial ice 2015061376 Artificial intelligence 2015061293 Assembling 2015061280 2015061281 Automation 2015061267 Autopilots 2015061395 Ballast water 2015061261 2015061265 Beam theory 2015061444 Bending moments 2015061454 2015061458 2015061467 Berthing 2015061408 Black Sea 2015061351 Blunt bodies 2015061363 Boats 2015061252 2015061278 2015061387 Bonded joints 2015061279 Boundary element method 2015061361 Boundary integral method 2015061402 Bow form 2015061264 Bridge remote control 2015061293 Bridges (ships) 2015061293 Bubbles 2015061372 2015061378 Buckling 2015061446 2015061465 Bulbous bows 2015061273 2015061447 Bulk carriers 2015061261 2015061341 2015061471 Buoyancy 2015061417

Buoys 2015061332 Butt welds 2015061477 2015061478 Calm seas 2015061355 Cargo capacity 2015061253 Catamarans 2015061389 2015061408 Cathodic protection 2015061489 Cavitation 2015061303 Cavitation noise 2015061369 Channels 2015061308 2015061309 Chemical tankers 2015061251 Circulation 2015061361 Coastal regions 2015061310 Coatings 2015061488 Collapse 2015061466 2015061469 Collision resistance 2015061447 2015061461 Collision risk 2015061328 Combined cycle power plants 2015061284 Combined loads 2015061457 2015061467 Compensators 2015061305 Composite materials 2015061412 2015061426 2015061480 2015061481 2015061482 2015061485 Compression 2015061437 2015061465 Compressive strength 2015061479 Computational fluid dynamics 2015061264 2015061302 2015061324 2015061331 2015061353 2015061355 2015061357 2015061358 2015061360 2015061362 2015061364 2015061366 2015061374 2015061383 2015061384 2015061398 2015061422 2015061424 2015061425 2015061427

KEYWORD INDEX K-1

Computational fluid dynamics 2015061428 2015061429 2015061432 2015061442 2015061490 Computer-aided design 2015061277 Computer-aided ship design 2015061255 2015061260 Containerships 2015061253 2015061254 2015061255 2015061256 2015061257 2015061258 2015061259 2015061287 2015061334 2015061337 2015061404 2015061405 2015061443 2015061458 2015061467 2015061468 2015061500 Contrarotating propellers 2015061357 Control 2015061342 Control systems 2015061305 2015061321 2015061392 2015061395 2015061408 Conversion 2015061315 Corrosion 2015061471 2015061487 Corrosion resistance 2015061488 Corrosion tests 2015061488 Cost analysis 2015061338 Cost benefit analysis 2015061283 Coupled motion 2015061393 Crack propagation 2015061452 2015061474 Crew boats 2015061277 Criteria 2015061405 Cross sections 2015061396 Curved shapes 2015061418 Cylindrical bodies 2015061413 2015061415 2015061417 2015061427 2015061433 Damage stability 2015061271 Data 2015061347 Data processing 2015061329 Decision making 2015061321 Deepwater 2015061301

Deepwater 2015061313 Derricks 2015061263 Design 2015061275 Design loads 2015061274 Design process 2015061268 Diesel electric propulsion 2015061283 2015061364 Diesel engines 2015061286 Discrete systems 2015061348 Distortion 2015061477 2015061478 Double hulls 2015061331 Drag coefficients 2015061384 Drag reduction 2015061378 2015061442 Drift forces 2015061439 Dynamic positioning 2015061262 2015061342 2015061379 2015061382 2015061390 Dynamic response 2015061472 Economies of scale 2015061500 Ecosystems 2015061297 Efficiency 2015061256 2015061334 2015061337 Eigenvalues 2015061450 Elastic plates 2015061437 Electric power 2015061282 Ellipsoids 2015061386 Emissions 2015061286 2015061499 Energy absorption 2015061447 2015061461 Energy conservation 2015061282 2015061378 Energy methods 2015061448 Environmental conditions 2015061275 Environmental loads 2015061455 Environmental protection 2015061298 2015061333 Error analysis 2015061400 Ethylene 2015061285 Explosions 2015061472 Extreme values 2015061454 Failure 2015061306 2015061486 Fatigue cracks 2015061452 Fatigue life 2015061300 2015061453 2015061463 2015061468 Fatigue strength 2015061470 Feasibility 2015061300 2015061312

K-2 KEYWORD INDEX

Ferries 2015061269 Fibre composites 2015061484 Fin stabilizers 2015061380 Finite element method 2015061263 2015061302 2015061366 2015061443 2015061445 2015061468 2015061472 2015061474 Fire extinguishing agents 2015061327 Fire extinguishing systems 2015061319 2015061326 2015061327 Fire prevention 2015061325 Fire safety 2015061319 2015061324 2015061326 Firefighting 2015061320 2015061323 Flaps (control surfaces) 2015061359 Flat plates 2015061384 Flexibility 2015061257 Flexible materials 2015061426 Flexural strength 2015061483 Floating bodies 2015061435 2015061439 Floating structures 2015061420 2015061433 Flow measurement 2015061379 Fluid structure interaction 2015061366 2015061412 2015061423 2015061424 2015061426 2015061435 2015061460 Forces 2015061354 Forward speed 2015061373 FPSOs 2015061274 2015061392 2015061394 2015061446 Fracture 2015061489 Freak waves 2015061391 2015061406 Free running models 2015061365 2015061411 Free surfaces 2015061371 2015061401 2015061424 Free vibration 2015061445 2015061456 2015061473 Fuel conservation 2015061290

Fuel conservation 2015061337 Fuel consumption 2015061286 2015061336 Full scale tests 2015061339 Fuzzy systems 2015061330 Gas carriers 2015061285 Gas turbines 2015061254 General arrangements 2015061260 Genetic algorithms 2015061266 Gravity structures 2015061430 Green function 2015061373 Grids 2015061282 Harbours 2015061311 Heat recovery 2015061283 2015061286 2015061287 Heaving 2015061305 2015061386 Heavy lift operations 2015061314 Heavy weather 2015061405 2015061491 High speed vessels 2015061278 2015061453 High strength steel 2015061485 Hull bottoms 2015061444 Hull damage 2015061464 2015061466 Hull form 2015061252 2015061264 2015061265 2015061273 2015061276 Hull girders 2015061457 2015061464 2015061466 2015061469 Hull materials 2015061485 2015061489 Hull vibration 2015061257 2015061443 Human factors engineering 2015061277 Hydrodynamic characteristics 2015061373 Hydrodynamic coefficients 2015061427 Hydrodynamic forces 2015061403 Hydroelasticity 2015061420 2015061426 2015061437 2015061443 Hydrofoils 2015061378 Ice conditions 2015061348 Ice control 2015061349 Ice loads 2015061459 Ice operations 2015061343 Ice properties 2015061376 Ice transiting vessels 2015061343 Icebreakers 2015061460

KEYWORD INDEX K-3

Imagery 2015061418 Impact strength 2015061480 Impact tests 2015061486 Incompressible flow 2015061371 Installing 2015061313 2015061314 Integral equations 2015061352 Interactions 2015061379 2015061382 2015061400 2015061439 Irregular waves 2015061436 Iteration 2015061414 Jacket structures 2015061429 Jackup platforms 2015061263 2015061455 Joints 2015061481 2015061482 Kalman filters 2015061310 Laminates 2015061483 2015061484 Large size 2015061420 Layout 2015061267 2015061284 Lift 2015061383 Lifting surface theory 2015061367 Liner shipping 2015061500 Liquefied natural gas 2015061258 Liquids 2015061431 LNG carriers 2015061299 2015061406 LNG handling 2015061295 LNG tanks 2015061274 2015061428 LNG transportation 2015061295 2015061350 Loading calculators 2015061336 Loads (forces) 2015061474 Longitudinal strength 2015061457 Low alloy steel 2015061485 Manoeuvring 2015061269 2015061354 2015061381 2015061398 2015061411 Marine engineering 2015061494 Maritime education and training 2015061325 2015061493 2015061494 2015061495 2015061496 2015061497 2015061498 Maritime industries 2015061494 Mathematical logic 2015061490 Mathematical models 2015061307

Mathematical models 2015061371 2015061381 2015061388 2015061390 2015061407 2015061408 2015061411 Mechanical properties 2015061482 Merchant fleets 2015061500 Meteorological data 2015061301 Midship sections 2015061266 Model basins 2015061423 Model tests 2015061262 2015061354 2015061365 2015061377 2015061404 2015061469 Monitoring 2015061321 2015061332 2015061333 Monte Carlo method 2015061434 Moored vessels 2015061409 Mooring lines 2015061306 Motion 2015061384 2015061425 2015061431 2015061433 Motor yachts 2015061271 2015061389 Multibody systems 2015061416 2015061439 Multiphase flow 2015061362 2015061378 Naval architecture 2015061353 2015061494 Naval vessels 2015061490 2015061491 2015061492 Neural networks 2015061339 Numerical analysis 2015061400 2015061403 2015061404 2015061421 2015061439 2015061441 2015061481 Numerical models 2015061352 2015061401 2015061409 2015061423 2015061435 Oblique seas 2015061397 Ocean currents 2015061303 Ocean engineering 2015061353 Ocean thermal energy conversion 2015061316

K-4 KEYWORD INDEX

Oceanographic data 2015061301 Offshore drilling 2015061305 Offshore engineering 2015061318 2015061330 2015061349 2015061494 Offshore industries 2015061302 2015061499 Offshore platforms 2015061313 2015061432 2015061441 Offshore structures 2015061275 2015061314 2015061448 2015061465 Oil spills 2015061331 2015061332 Optimisation 2015061256 2015061264 2015061266 2015061268 2015061269 2015061270 2015061276 2015061340 2015061344 2015061361 2015061499 Oscillating bodies 2015061427 Panama Canal 2015061299 Particulate control 2015061291 Passage planning 2015061344 Passenger ships 2015061273 Passing vessels 2015061400 Passive systems 2015061385 2015061392 Patrol craft 2015061492 Performance 2015061303 Piping systems 2015061267 Pitching 2015061386 2015061392 Pitting corrosion 2015061472 Planing hulls 2015061355 2015061387 Plastics 2015061484 Plates 2015061420 2015061452 2015061476 2015061479 Platform decks 2015061432 Platform design 2015061263 2015061272 Platform motions 2015061391 2015061410 2015061441 Port authorities 2015061297

Port management 2015061298 2015061333 Ports 2015061296 Potential flow 2015061357 Power plant selection 2015061254 Power prediction 2015061339 Predictions 2015061345 2015061381 2015061399 Prefabrication 2015061281 Pressure distribution 2015061308 2015061309 2015061363 2015061415 Probabilistic methods 2015061271 2015061343 2015061487 Probability 2015061328 2015061345 2015061436 2015061454 Procedures 2015061356 Products tankers 2015061290 Propeller cavitation 2015061369 Propeller efficiency 2015061354 2015061365 2015061366 2015061367 2015061368 2015061369 2015061376 Propeller flow 2015061398 Propeller ice interaction 2015061376 2015061460 Propeller loading 2015061368 Propeller races 2015061357 2015061367 Propeller shafts 2015061288 2015061292 Propeller size 2015061370 Propeller strength 2015061460 Propellers 2015061375 2015061379 2015061426 Propulsive efficiency 2015061261 2015061359 Propulsive performance 2015061265 2015061346 2015061356 2015061364 Propulsive power 2015061370 Quays 2015061311 Radial flow 2015061354 Random seas 2015061393 Rectangular plates 2015061456 2015061486

KEYWORD INDEX K-5

Reinforcement (structures) 2015061447 Reliability 2015061484 Residual stress 2015061475 2015061476 Resistance 2015061273 2015061362 2015061374 Resonant frequency 2015061414 2015061445 Response surface methodology 2015061266 Reynolds number 2015061415 Ride comfort 2015061389 Rigid inflatable craft 2015061252 Risers 2015061300 2015061412 2015061414 2015061417 2015061438 2015061440 2015061445 2015061446 Risk analysis 2015061295 2015061318 2015061322 2015061329 2015061330 Ro/ro safety 2015061319 Ro/ro ships 2015061269 2015061359 Roll stabilizers 2015061380 Rolling 2015061385 2015061388 2015061393 2015061394 2015061404 Ro-ro ships 2015061258 Rough seas 2015061468 Routes 2015061338 Rudders 2015061383 2015061411 Safety 2015061330 Sandwich structures 2015061461 2015061480 2015061483 Scheduling 2015061280 Sea state 2015061317 Sea trials 2015061315 2015061356 2015061387 Seakeeping 2015061358 2015061389 2015061392 2015061402 2015061403 2015061405 2015061498

Seawater 2015061292 2015061320 Self propulsion 2015061375 Semisubmersible rigs 2015061272 2015061301 Semisubmersibles 2015061304 2015061391 2015061410 Shafts 2015061339 Shallow draft vessels 2015061281 Shallow water 2015061307 2015061400 Shear strength 2015061465 Ship collisions 2015061328 2015061462 Ship conversion 2015061294 Ship decks 2015061451 Ship design 2015061253 2015061254 2015061256 2015061257 2015061258 2015061259 2015061261 2015061262 2015061269 2015061270 2015061271 2015061273 2015061278 Ship efficiency 2015061290 Ship hydrodynamics 2015061355 2015061373 Ship identification 2015061329 2015061347 Ship motions 2015061380 2015061386 2015061387 2015061395 2015061397 2015061399 2015061401 2015061402 2015061406 2015061407 2015061409 2015061436 Ship operation 2015061342 2015061345 Ship performance 2015061334 2015061340 2015061343 2015061346 Ship performance monitoring 2015061341 Ship response 2015061345 2015061406

K-6 KEYWORD INDEX

Ship sides 2015061396 2015061461 Ship size 2015061500 Ship speed 2015061309 2015061365 2015061405 Ship structures 2015061474 2015061485 2015061487 Ship waves 2015061309 Shipboard fires 2015061296 2015061322 2015061324 2015061325 2015061490 Shipboard safety 2015061321 Shipbuilding 2015061279 2015061280 2015061495 Simulation 2015061302 2015061350 2015061390 2015061431 Slamming 2015061418 2015061436 2015061444 2015061458 Sloshing 2015061274 2015061421 2015061422 2015061428 2015061431 Slow steaming 2015061287 Small craft 2015061252 2015061492 Small size 2015061298 Smoke 2015061319 2015061324 Solar energy 2015061346 Solitary waves 2015061307 Spill tracking 2015061332 Stability 2015061294 2015061320 2015061491 Standards 2015061381 2015061491 Statistical analysis 2015061351 2015061448 Steam power plants 2015061284 Steel 2015061481 2015061482 2015061489 Steel structures 2015061479 Stern location 2015061359 Stiffened plates 2015061450 2015061465

Stiffened plates 2015061475 Stiffened shells 2015061473 Stochastic processes 2015061434 Strain measurement 2015061459 Strength 2015061300 2015061320 Stress analysis 2015061470 Stress concentration 2015061463 2015061481 Stress corrosion 2015061489 Stresses 2015061430 Strip method 2015061386 Structural analysis 2015061449 Structural monitoring 2015061453 Structural reliability 2015061466 Structural response 2015061444 2015061446 2015061450 Structural strength 2015061294 Submarines 2015061360 2015061398 Suction dredgers 2015061322 Suez Canal 2015061338 Supercavitating hydrofoils 2015061361 Surface roughness 2015061415 SWATH ships 2015061270 Tandem arrangement 2015061413 Tankers 2015061261 2015061294 2015061331 2015061462 Tanks 2015061421 2015061422 Temperature gradients 2015061478 Tension leg platforms 2015061300 2015061304 Thin plates 2015061470 Thrust deduction 2015061375 Thrust 2015061382 Thrusters 2015061365 2015061379 2015061382 Tidal power 2015061315 Time domain 2015061364 2015061394 Torque 2015061459 Torsional vibration 2015061288 Towed vessels 2015061407 Towing cables 2015061407 Traffic simulation 2015061329 Transponders 2015061347 Transportation costs 2015061338 Transportation modes 2015061499 Trawlers 2015061368 Trim 2015061336 2015061340

KEYWORD INDEX K-7

Trimarans 2015061396 2015061397 Tugs 2015061339 Turbines 2015061303 Turbulence 2015061424 Turbulent flow 2015061401 Two stroke engines 2015061286 Ultimate strength 2015061457 2015061462 2015061464 2015061469 2015061471 2015061475 2015061476 Uncertainty 2015061374 2015061377 2015061463 Underwater structures 2015061419 Variations 2015061452 Vessel descriptions 2015061251 2015061252 Vibration 2015061437 2015061448 Vibration analysis 2015061451 2015061456 Virtual reality 2015061260 Viscous resistance 2015061360 Visibility 2015061319 Vortex induced vibration 2015061412 2015061414 2015061415 2015061417 2015061438 2015061440 Vortex shedding 2015061413 2015061425 2015061433 2015061441 Voyage estimating 2015061344 Wall effects 2015061413 Warning systems 2015061336 Water entry 2015061418 Water lubrication 2015061292 Water waves 2015061352 Waterjet propulsion 2015061408 Wave climate 2015061351 Wave diffraction 2015061416 Wave energy 2015061346 Wave energy conversion 2015061312 Wave forces on structures 2015061432 Wave forecasting 2015061310 Wave groups 2015061391 Wave height 2015061310 2015061317 2015061345 2015061410

Wave loads 2015061396 2015061434 2015061454 Wave loads on ships 2015061449 Wave loads on structures 2015061429 2015061430 Wave models 2015061310 2015061352 Wave patterns 2015061308 Wave periods 2015061410 Wave propagation 2015061309 2015061311 2015061419 Wave resistance 2015061276 2015061360 Waves 2015061435 Weather forecasting 2015061335 Weather routing 2015061335 Wedges 2015061383 2015061418 Welded joints 2015061470 Welding 2015061475 2015061478 Weldments 2015061476 Wheelhouses 2015061277 Whipping 2015061454 2015061458 2015061467 2015061469 Wigley models 2015061360 2015061371 2015061401 2015061403 Wind 2015061351 Wind conditions 2015061317 Wind propulsion 2015061346 2015061364 Wind tunnel tests 2015061442 Wings 2015061361 Workboats 2015061281

K-8 KEYWORD INDEX

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