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ISSN 1233-2585

POLISH MARITIME RESEARCH

in internetwww.bg.pg.gda.pl/pmr/pmr.php

PUBLISHER :

3 JAN P. MICHALSKI Preliminary Designing Method of External Pressure Vessels for Sea Subsurface Applications10 P. FLASZYSKI, J. A. SZANTYR, R. BIERNACKI, P. DYMARSKI, M. KRASKOWSKI A method for the accurate numerical prediction of the tip vortices shed from hydrofoils18 TOMASZ ABRAMOWSKI, JAKUB HANDKE, TADEUSZ SZELANGIEWICZ Numerical analysis of influence of streamline rudder on screw propeller efficiency23 HASSAN GHASSEMI, FATEMEH HOSEINI DADMARZI, PARVIZ GHADIMI, BABAK OMMANI Neural network-PID controller for roll fin stabilizer29 ZBIGNIEW KORCZEWSKI Entropy function application in the selection process of diagnostic parameters of marine diesel and gas turbine engines36 JERZY GIRTLER, ZBIGNIEW KORCZEWSKI, JACEK MACZAK Operational problems of large power diesel engines combusting biofuels, considered together with assessment of their operation44 ZYGMUNT PASZOTA Energy losses in the hydraulic rotational motor definitions and relations for evaluation of the efficiency of motor and hydrostatic drive55 BOGUSAW ZAKRZEWSKI, TOMASZ OKIETEK Assessing the applicability of new refrigerants in marine cooling systems60 EUGENIUSZ RANATOWSKI Problems of welding in shipbuilding - an analytic-numerical assessment of the thermal cycle in HAZ with three dimensional heat source models in agreement with modelling rules. (Part II)67 S. D. KIM, H. J. LEE Boundary element modelling of wave diffraction by interaction with wave-offshore structure and dredged region72 XIAO-YAN XU, JANUSZ MINDYKOWSKI, C. L. PHILIP CHEN Study on Hybrid Filtering Solution for Marine Electric Network

CONTENTS

POLISH MARITIME RE SE ARCHNo 2(65) 2010 Vol 17

POLISH MARITIME RESEARCH is a scientific journal of worldwide circulation. The journal ap pe ars as a quarterly four times a year. The first issue of it was published in September 1994. Its main aim is to present original, innovative scientific ideas and Research & Development achie ve ments in the field of :

Engineering, Computing & Technology, Mechanical Engineering,which could find applications in the broad domain of maritime economy. Hence there are published papers which concern methods of the designing, manufacturing and operating processes of such technical objects and devices as : ships, port equ ip ment, ocean engineering units, underwater vehicles and equipment as

well as harbour facilities, with accounting for marine environment protection.The Editors of POLISH MARITIME RESEARCH make also efforts to present problems dealing with edu ca tion of engineers and scientific and teaching personnel. As a rule, the basic papers are sup ple men ted by information on conferences , important scientific events as well as co ope ra tion in carrying out in ter na-

tio nal scientific research projects.

Editorial

Scientific BoardChairman : Prof. JERZY GIRTLER - Gdask University of Technology, PolandVice-chairman : Prof. ANTONI JANKOWSKI - Institute of Aeronautics, Poland

Vice-chairman : Prof. MIROSAW L. WYSZYSKI - University of Birmingham, United Kingdom

Dr POUL ANDERSENTechnical University

of DenmarkDenmark

Dr MEHMET ATLARUniversity of Newcastle

United Kingdom

Prof. GRAN BARKChalmers Uni ver si ty

of TechnologySweden

Prof. SERGEY BARSUKOVArmy Institute of Odessa

Ukraine

Prof. MUSTAFA BAYHANSleyman De mi rel University

Turkey

Prof. MAREK DZIDAGdask University

of TechnologyPoland

Prof. ODD M. FALTINSENNorwegian University

of Science and TechnologyNorway

Prof. PATRICK V. FARRELLUniversity of Wisconsin

Madison, WI USA

Prof. WOLFGANG FRICKETechnical UniversityHamburg-Harburg

Germany

Prof. STANISAW GUCMAMaritime University of Szczecin

Poland

Prof. ANTONI ISKRAPozna University

of TechnologyPoland

Prof. JAN KICISKIInstitute of Fluid-Flow Machinery

of PASciPoland

Prof. ZYGMUNT KITOWSKINaval University

Poland

Prof. JAN KULCZYKWrocaw University of Technology

Poland

Prof. NICOS LADOMMATOSUniversity College London

United Kingdom

Prof. JZEF LISOWSKIGdynia Ma ri ti me University

Poland

Prof. JERZY MATUSIAKHelsinki Uni ver si ty

of TechnologyFinland

Prof. EUGEN NEGRUSUniversity of Bucharest

Romania

Prof. YASUHIKO OHTANagoya Institute of Technology

Japan

Dr YOSHIO SATONational Traffic Safety

and Environment LaboratoryJapan

Prof. KLAUS SCHIERUniversity of Ap plied Sciences

Germany

Prof. FREDERICK STERNUniversity of Iowa,

IA, USA

Prof. JZEF SZALABydgoszcz Uni ver si ty

of Technology and AgriculturePoland

Prof. TADEUSZ SZELANGIEWICZTechnical University

of SzczecinPoland

Prof. WITALIJ SZCZAGINState Technical University

of KaliningradRussia

Prof. BORIS TIKHOMIROVState Marine University

of St. Pe ters burgRussia

Prof. DRACOS VASSALOSUniversity of Glasgow

and StrathclydeUnited Kingdom

3POLISH MARITIME RESEARCH, No 2/2010

INTRODUCTION

Tight submerssible vessels intended for the fulfilling of assumed functions deep in water, capable of carrying large external hydrostatic loads find many civil and military applications such as submarines and submersible vehicles, bathyscaphes, crude-oil and gas storage tanks, or casings for measurement apparatus to conduct underwater oceanological experiments [ 3]. For example, the measuring, recording and investigating of physical fields of seas and oceans is conducted by means of echo-location systems (Subsurface buoy mooring systems) composed of such elements as: floats (buoys of a required buoyancy) vessels containing measuring and recording apparatus vessels containing electric storage batteries anchoring device in the form of ballast tension members joining elements of a module.

The systems elements are connected to each other by means of elastic tension members, i.e. cables or chains. The vessels shell plating is loaded by hydrostatic pressure proportional to submersion depth, sometimes also by a hydrodynamic load due to water current or surface wave motion. Also, concentrated loads generated by tension members are applied to the vessel. For functional reasons the vessels structure should ensure its buoyancy, shape and watertightness to be maintained.

This paper contains a description of the engineering method for the preliminary designing of echo-location system, which serves to determining design solutions satisfying a set

Preliminary Designing Method of External Pressure Vessels for Sea Subsurface Applications

ABSTRACT

This paper describes a unique engineering method intended for the preliminary designing of marine echo-location systems. The solved designing problem consists in determining geometrical parameters and selecting structural materials for a vessel of a buoyancy necessary to contain measuring instruments of a given mass, as well as its maximum gabarites and operational submersion depth. The assumed variability range of the systems parameters determines a space of permissible applicability parameters of the method. Stress level related to permissible and critical stresses was assumed to be safety criterion for the vessel. The method may be applied also to solving converse problems consisting in

determining maximum permissible submersion depth for a vessel made of assumed structural materials and having given geometrical parameters. The presented description of the method is illustrated by an

example of its application.

Keywords: subsurface buoy mooring systems; external pressure vessels

of functional, technological and mechanical assumptions. Original algorithms for the determining of parameters of vessels subjected to action of external pressure in the aspect of their buoyancy, shell structure strength and form stability are also presented in it.

Applicability of the method is determined by ranges of permissible values of vessels form parameters, external pressure values as well as a kind of structural material. The method may be useful in particular for the preliminary designing of echo-location systems (Subsurface buoy mooring systems) within the area of: designing their geometrical configuration designing geometrical parameters of their vessels selection of their structural materials assessment of quantity of their mass determining optimum design solutions in an assumed

sense.

FORMULATION OF DESIGNING PROBLEM

The designing problem consists in determining geometrical parameters and selection of a structural material for a vessel of a given effective buoyancy, capabl