annual report 2002 - thermo · laser diagnostics of dense sprays theoretical and experimental...

CERC – Annual Report 20021

C E RC

Chalmers University of Technology

Combustion Engine Research Center

AnnualReport2002

CERC – Annual Report 2002 2

CERCCombustion Engine Research Center

Table of ContentsGeneral background

Preface

Summary of the seventh year – 2002

Scientific results and future outlook

Modeling of spray formation, ignitionand combustion in internal combustionengines

Spray-guided gasoline direct injection

Laser diagnostics of dense sprays

Theoretical and experimentalinvestigations of combustion of shortduration small diameter sprays indiluted air

Torque sensors for engine applications

Applied combustion diagnostics

Influence of cavitation and hydraulic flipon spray formation, ignition delay,combustion and pollutant formation

Human resources

Finances during the period 2001-2003

References

The cover

LES simulation of a Diesel spray in aconstand volume, illustrating thecomplex flow field. Colours are bytemperature and elevation by heat-release.

General BackgroundThe centre was founded on November, 1 1995 by a decision of the Boardof Chalmers University of Technology and was based on a three-partyagreement between the Swedish Board for Technical and IndustrialDevelopment (NUTEK), Chalmers University of Technology and a group offive Swedish industrial companies, Husqvarna AB, SAAB Automobile AB,Scania CV AB, Volvo Car Corporation and Volvo Truck Corporation. Theagreement defines each party’s responsibilities for financial commitment,scientific goals and the use of research results.

In 1997 the co-ordination was transferred to the Swedish National EnergyAdministration (STEM) now changed name to Swedish Energy Agency.Currently the following industrial companies are full members of thecentre in Stage 3:� ABB Automation Products AB� Aspen Petroleum AB� AB Volvo Penta� Statoil AS� Volvo Power Train AB� Volvo Car Corporation� Scania CV AB� Saab Automobile Powertrain AB

Stage 4 will start in 2004 for another two years and after this 10- yearperiod the centre is expected to be less depending on financial supportfrom STEM and strenghtened the relationship between the University andthe Industry.

The centre is defined as one of twenty-eight Competence Centres inSweden of long term importance for Swedish industry. The centre is aforum where joint industrial and academic research is performed. Thepurpose is to provide and build up a concentrated inter-disciplinaryresearch group in which the participating companies can actively take partin and gain the benefit of a long-term perspective.

The centre named CERC for Combustion Engine Research Centre initiallyconcentrated on the mobilisation of a research platform in internalcombustion engine technology focusing on fuel efficient engines with lowemission.

The centres long-term objectives are to carry out fundamental research ofsignificant industrial interest focused on the Otto and Diesel combustionprocesses including alternative fuels and control system and to transferknowledge between the Academic community and the Industrial membersin an inter-disciplinary way. Strategically important research areas aredecided by the scientists at Chalmers in co-operation with representativesfrom the Industry and advise from the Scientific Advisory Board. Theresearch projects have been and are in the areas of both basic and appliedresearch.

The governing board consists of the chairman, three members from theacademic community, four members from the participating companies andone member from the Swedish Energy Agency (STEM).

2

3

4

5

7

10

12

17

15

20

22

19

23

25


Preface

Closer collaboration and relationship between the Industry and theUniversity will be even more accentuated in the next coming years in Swedenand in Europe. The European 6th Framework Programme for instance stressthe importance and requirement of a European consortium to fulfill theeligible criteria.The competence centre CERC should be a neutral platform where theindustrial and academic expertise will meet and perform research projectsof common interest. Expected outcome is an enhanced industrial orientationof the University. The Industry would take the opportunity to reduce theirbasic and applied research cost as well as increase their knowledge byparticipating more actively in research programme.CERC concentrates on research targeted at reducing both the engine exhaustgas emission and the specific fuel consumption. The projects at the centreinclude both experimental validations of models and systems and newconcepts associated with alternative fuels. Furthermore new diagnosticstools are used in the research. Several projects concentrate on differenttypes of spray formation, spray diagnostics and flame propagation. Most ofthe projects are so called ”horizontal projects” which have an interest frommost of the members in the centre.Research related to internal combustion engines has been recognised asstrategic for the Swedish industry. The integration of important elements inthe research using advanced forms of mathematical modelling and enginetechnology is a natural platform when enhancing the long-term com-petitiveness of the industry from an economical and environmentallysustainable perspective.These demands and expectations stress the internal engine manufacturersas well as systems and components supplier and justifies the formation ofcompetence centres such as CERC.CERC will continue to strive for closer contacts with other interested partiesin order to attract and encourage more companies to join the CombustionEngine Research Centre. Besides the research results both the Universityand the Industry will get benefits both from academic knowledge point ofview and the education and training of professional Researchers meetingthe future need and demand of the University and the Industry.

Sivert HiljemarkDirector, Combustion Engine Research Centre


Summary

The Centre of Excellence in Internal Combustion Engines (Combustion Engines ResearchCentre - CERC) was formally established on November, 1 1995 and inaugurated on March,26 1996.

The centre organises and conducts research and development within the field of internalcombustion engines in collaboration with industrial companies, university departmentsand other research centres in Sweden and abroad .

The vision of the centre is to be an internationally prominent centre focusing on long-term industrial needs with a special interest in reducing specific fuel consumption andharmful engine exhaust gas emissions from gasoline and diesel engines. This calls for acombination of inter-disciplinary engine, fuel and emission research. Research projectshave so far covered spray formation, spray diagnostics, flame propagation studies, enginegoverning and alternative concepts of different types.

During this reporting period efforts have been made to establish an inter-disciplinarynetwork in which both academic and industrial scientists can get together to discuss thestrategic direction of proposed research. The Centre’s original three University depart-ments have been joined by others and financial support has been obtained from bothinternal and external interests.

Current international collaboration for CERC includes, to mention a few, participation inthe FIRE code development with AVL LIST (Austria) and in the FOAM code developmentwith Imperial College in London. Work as als ben carried out on developing a modifiedspray rig for Chalmers University of Technology. This is based on the RWTH Aachen high-pressure combustion chamber which together with a laser and a high speed camera hascontributed to a great extent to validate our models.

In 2002 CEC organiserad two Scientific Advisory Board Meetings and one Seminar for allCERC Partners and Researchers working on CERC projects. The discussion from theSeminar and the Scientific Advisory Board will give valuable inputs and guidelines forthe research projects and its Reference Group in year 2003 and Stage 4 starting 2004.From the December meeting the following statements from Professor C Arcoumanis, CityUniversity (London, UK) and Professor C Atkinson West Virginia University (USA)summarise the challenge to the CERC’s future.

Professor Arcoumanis:”This second meeting of 2002 provided the opportunity to evaluate the progress of thevarious research projects and to discuss issues of relevance with members of theBoard. The overall impression was that the choice of the research topics was on aver-age justified by the expertise available in the group and the interests of the industrialmembers, while offering the opportunity for new area of research to be explored withboth long- and short-term benefits to the industrial partners.”

Professor Atkinson :”It is yet again apparent that CERC is developing a research program of world-classquality in the areas of combustion diagnostics and simulation and modeling, and forthis the Centre directorate, project leaders, faculty, students and staff are to becommended. The future of the Centre revolves around the question of sustainability -the sustainability of funding - and for this reason it is recommended that the Centrefine-tune its focus, broaden its appeal to potential funding sources (both industrialand institutional) and set in place further measures for enhanced accountability.”

During 2002 the strategy discussion started for Stage 4 (2004 and 2005) and thereafter,and the next audit in Autumn 2003 by the international team of experts will be of signifi-cant importance to the future of CERC. New research projects will start in 2003 follow-ing finishing of three projects by CERC supported Ph.D Students.


In 2002 all the seven research projects were progressing satisfactorily with the common objective ofunderstanding and improving the combustion engine to meet future performance demands of cus-tomer and satisfying emission legislation and global environmental issues such as CO2.At the Eucar Conference 2002 a fuel roadmap (Figure 1) andsome general aspects were agreed uponby the motor industry and some oil companies as follows:

� It was agreed by all participants that the joint long term target for future fuels is to secure a roadtransport system that makes use of fuels and energy systems that are least polluting, have anessential CO

2 reduction potential (well-to-wheel) and are based on renewable energy resources.

� The changes that are required in order to reach this target are an immense challenge for the auto-motive and the energy industry and can only be reached in an evolutionary process without abruptchanges.

� Considering cycle time scales of the vehicle and energy industry, it can be concluded that fossilfuels and conventional power trains will be dominant in the near to mid-term future. For longdistance transport applications (trucks and busses), this may be the case even in the longer termfuture.

� For light duty vehicles, hydrogen has been identified as a potential “ideal” future fuel if it can beproduced competitively from renewable resources. In the long-term, hydrogen could be a majorenergy carrier for vehicle propulsion systems.

� In order to achieve this, a CO2 neutral, energy efficient, economically viable and sufficiently large

hydrogen source path must be identified.

� Given the longer time scale for hydrogen introduction and the short to medium term requirementsfor CO

2 reduction, other alternative fuels and power train optimizations have to be developed and

utilized for the transition phase that are economically and ecologically feasible for both the energyand the automotive industry.

� Synthetic liquid fuels (GTL) based on biomass could be the pathways leading to long term sustain-able solutions. As an intermediate step, natural gas is used as energy resource for making thesedesirable designed fuels.

Scientific resultsand future outlook

Figure 1. Fuels for road transpor t.(Source: Eucar Conference 2002).


Figure 3. World use of transpor tationfuels. There is a transition from petroleumfuel in internal combustion engines forcars (oil: cars) to hydrogen used in fuelcells (H2: cars). The same transitionoccurs in trucks, buses and ships(freight). (Source: Azar, Lindgren,Andersson 2003: “Global energy meetingstringent CO2 constraints... etc).

Figure 2. Diesel engine technology drivers.

Fossil fuels for transportation is predicted to be available for at least another 50 years (Figure 3) andthe internal combustion engine will have a major impact on environment for the next 30 years forminimum.

The emission legislation for trucks (Figure 2) and cars and the environmental requirement ofreducing CO2 will be a significant challenge for the engine researchers for many years to come.

New engine technologies and new designed and renewable fuels will be introduced and newcombustion processes will combine the benefits of diesel and gasoline engines with very low emissionand best efficiency from well to wheel. A likely scenario is shown in figure 4.

As a summary there is fossil fuel available for transportation in the foreseeable future. Fullfillinglegislation and global environmental issues such as CO2 will require major research into engineconcepts and combustion processes.

The required changes for the automotive industry will be the guidelines for the future researchprojects at CERC.

Figure 4. Power train Technology Trends.(Source: Eucar Conference 2002).


Modeling of Spray Formation, Ignition and Combustionin Internal Combustion Engines

Jerzy Chomiak, Professor Emeritus,Project leader

Valerie Golovitchev, Associate professor

Niklas Nordin, Researcher, Ph.D

Feng Tau, Ph.D. student

Niklas Nordin, Researcher, Ph.D.,Thermo and Fluid Dynamics

I want to create a research-tool for makingreliable spray combustion simulations,where the models behave in a good andexpected manner, so that, someday, realpredictive spray simulations will be possible.As the computational power is increasing,so is the possibility to make more realisticcomputations. This requires, however,that the computational tool can takeadvantage of this ‘power’ and is reliableenough, so that it can be used to reduceboth the time and cost when developinga new and cleaner engine.

Figure 5. The simulated soot cloudstructure and movement based on theupdated soot model (b) comparedwith experimental data (a). The unitsfor soot mass concentration are g/m3.

This report reviews progress achieved in theproject during 2002. The main research areasduring this period were: further development andvalidation of pollutant formation predictions inDiesel combustion, fine resolution (LES) studiesof spray combustion, and application studies ofthe modeling approach developed in the projectto engine case studies. Studies of air dilutioneffects were also performed to investigate theEGR effects on ignition delay, soot and NOxemissions in Diesel combustion.

The research on pollutant formation predictionsis summarized in the Ph.D thesis of Feng Tao:“Numerical Modeling of Soot and NOx Formationin Non-Stationary Diesel Flames with ComplexChemistry”. In this field the major progress hasbeen achieved in soot modeling by replacing thepreviously used phenomenological model by amore developed one in which soot formation isapproximated by four quasi-global stages: particle

nucleation, surface growth, surface oxidation andparticle coagulation, each of which is representedby few reaction steps according to recentliterature data. The formation of soot particles islinked with gas phase chemistry via diacetyleneand naphthalene which are presumed to be theleading species of particle inception/nucleation.The soot surface growth is described using theactive site model, and the oxidation mechanismincludes both the O2 and OH oxidation models.Some reaction rate constants in the above systemwere modified and quantitative agreement hasbeen achieved with the available experimentaldata for n-heptane spray combustion in Diesel likeconditions. This is illustrated in Figure 5 and 6,showing the evolution of the soot cloud, itsstructure and location and soot massconcentration compared with experimental data.

Figure 6. Comparison of the simulatedand measured maximum soot massconcentration (SMC). The dashed linerepresents the averaged total sootmass normalized by the fuel mass(emission index).


Our simulation method as all the others in thefield, is based on the k-e model of turbulence. Themodel is a quasi-laminar one as the Reynoldsnumber of the flow calculated using turbulentviscosity is very low, typically smaller than 100.Thus no fluctuations are present in the calculatedflow field which has all the features of a laminarflow with variable viscosity. To estimate the effectsof this approximation and evaluate the prospectsof fine resolution modeling of the flow an attempt

has been undertaken to perform Large EddySimulation (LES) of a Diesel flame.

LES studies are attractive since it captures thevery transient and 3D nature of the Dieselinjection and ignition processes, including thefluctuations, see Figure 7. We may note that thefluctuations, although strong, do not change thephysical structure of the flame as they cause justa random movement of the reaction zone.

Figure 7. Example of the complex flowstructures obtained when per forminga LES calculation.

Moving from RANS to LES requires, however, thatthe computational cells are small enough tocapture the larger flow structures and, thus, theirsize will be of the same order as the injectororifice. This violates the underlying assumptionthat the liquid volume fraction of the cell is muchsmaller than the gas volume fraction. Initial studiesindicate that because of this, the near-nozzleevaporation is reduced and, hence, the flame lift-off increases by a pure numerical and non-physical effect. Further drawbacks of LES are thememory requirements and computational timewhich is increased from days, or weeks, to months.LES studies are, thus, more of an academic interestthen for industrial use. Further studies will focuson whether performing a true LES is reallynecessary or if it is sufficient to do a Very LargeEddy Simulation (VLES) and how much the resultsdiffer from RANS.

Since, practical diesel fuels consist of a greatnumber of aliphatic and aromatic compounds, andtheir combustion kinetics is too complex to bemodeled using a comprehensive chemicalmechanism, a model for surrogate fuels was

developed for the numerical simulations. Aliphaticcomponents are represented by a long chainhydrocarbon such as n-heptane due to its cetanenumber of approximately ~ 56, which is similarto the cetane number of conventional diesel fuel.Aromatic components significantly contribute tosoot formation. The diesel fuel surrogate, whichcan sufficiently represent the properties of realfuel is assumed to be a 70/30 % mixture of n-heptane, C7H15, and toluene, C7H8. The alternativemodel consisting of the mixture of n-dodecaneand a-methylnaphthalene was also proposed. If thephysical properties of the model fuel arerepresented by properties of real diesel oil, thedifference in the kinetic models seems not to becritical.

The predicted ignition delays simulating shock-tube experiments for fuel surrogate and itscomponents are presented in Figure 8a.


The emission of soot particles from dieselengines is a well-known problem. Besidethe negative effect on human health, sootindicates also a reduced efficiency of fuelconsumption and environment. To meetthe stringent fuel and environmentalregulations, engineers are seeking theways to optimise diesel engines withengineering and fluid dynamic tools.Despite that the detailed studies of sootformation exist in the area of chemistry/physics, never theless, the commonmultidimensional diesel modell inghandles the soot formation problem bysimplified engineering models. To bridgethe gap between the engineering andnon-engineering, my goal is to develop anengineering acceptable soot formationmodel and then to apply the modeltogether with detailed gas-phasechemistry for diesel combustion analysisand design.

Feng Tao, Ph.D Student, Lic. Thermoand Fluid Dynamics

Figure 8. Calculated a) ignition delaysfor diesel oi l sur rogate and i tscomponents simulating shock tubeexperiments: p0=41.0 bar, f = 1 forall compounds, and b) ignition delaysfor the fuel surrogate vs experimentaldata on auto-ignition of real dieselfuel in the constant volume vesselwith a generator of turbulence:p0=50.0 bar, T0=800 K, minj=6.0 mg,tinj=1.28 ms.

It can be seen that auto-ignition properties of thefuel surrogate are similar to those of n-heptane.

Further model validation was carried out usingdiesel spray auto-ignition data were ignitiondelays with and without turbulence weremeasured in the constant volume chamber fordifferent air initial temperatures at the Dieselrelevant conditions: p0=50 bar, T0=800 K; minj=6.0mg, and tinj=1.27 ms, respectively. Realisticinjection data obtained from the Institute ofThermodynamics, Aachen, have been used in themodeling. The results of the comparisonpresented in Figure 8b show good agreementbetween predictions and experimental data.

Finally, the computer model has been applied tothe simulation of the Scania D12 8-spray DI engineusing a 45o sectoral mesh (50x25x15 cells in thebowl and 81x25x30 cells in the squish regions).The ring land and gasket volume are accountedfor in the simulation results presented in Figure9 a-c. The predictions are confirmed to be in areasonable agreement with optical diagnosticsdata. Since the flow has a high swirl number, equalto 2.1, a non-symmetrical parameter distributionon the side walls of the computational region ispredicted, confirming the potential of capturingswirl effects by the simulation.

a) b)

a) b)

c)

Figure 9. Calculated a) temperature, b) soot (inmg/m3), and c) NOx (in mass fraction) distributionsin the side slices of the sectoral mesh at 15 Cadeg ATDC for the Scania D12 Diesel Engine.


Spray-Guided Gasoline Direct InjectionIngemar Denbratt, Professor,Project Leader

Petter Dahlander, Researcher, Ph.D

Mikael Skogsberg, Ph.D student

Ronny Lindgren, Ph.D student

Fredrik Persson, Ph.D student

Direct injection gasoline engines are operated intwo modes, stratified and globally lean at lowspeeds and loads, and homogeneous stoichiometric(or rich) in the remaining load range. Directinjection engines can also be operatedhomogeneous in the entire load and speed areawith significant amounts of EGR at low loads andengine speeds. For stratified charge, late injectionsare used, in the range 70-20 CAD before top deadcentre depending on combustion system andoperational conditions, whereas with homogeneouscharge an early injection is used, which in generalmeans an injection during the intake stroke.

There are basically three ways of achieving astratified combustion:

� Wall-guided systems. A wall, usually the pistontop, is used to stabilize and transport the air-fuel mixture to the spark plug. A large distancebetween the injector, often placed at the sideof the combustion chamber, and the sparkplug(so called wide spacing) lead to a long mixturepreparation time and as a consequence a highdegree of over-mixing occur, which lead to anon-combustible extremely lean mixture in theperiphery of the fuel cloud. Due to the fact thatthe piston is used to guide the spray, a highdegree of wall wetting is also common, whichlead to high HC-emissions, soot production anda low fuel conversion efficiency compared tothe theoretically achievable efficiency. Wall-guided systems have shown improvements infuel consumption of between 10 to 15%.

� Air-guided systems. A well-defined gas motion(tumble) is used to transport the air-fuelmixture to the spark plug. The geometry issimilar to the wall-guided system, i.e. widespacing. The combustion is however verydifficult to optimize for all loads and speeds.This combustion system must be consideredas the least likely.

� Spray guided systems. The fuel spray is ignitedat the periphery by a spark plug located closeto the injector; at most 20 mm from the injector.Consequently, this concept is called closespacing. Since the fuel concentration gradientalong the periphery of the spray is very high,the spray has to be very stable regardless ofthe in cylinder pressure conditions. Thiscombustion system is therefore more sensitiveto injector mounting tolerances than a wall-guided system. Spray guided systems havereported improvements in fuel consumptionof around 25% with relatively low HC emissions,compared to MPFI. The soot emissions arecomparable to the wall-guided systems. A largeadvantage with a spray-guided system is thatthe stratified operating area is considerablylarger than for a wall-guided system.

Petter Dahlander, Researcher, Ph. D,Thermo and Fluid Dynamics

I have a got a PhD in CFD at Thermo andFluid Dept., Chalmers, and star tedworking with this project in November2002. I wil l be working both withexperiments and simulations of spraysand combustion.

Mikael Skogsberg, Ph. D Student,Thermo and Fluid Dynamics

I star ted working with this project inJanuary 2002 after I got my MSc degreeat Mechanical Engineering at ChalmersUniversity of technology.

Ronny Lindgren, Ph. D Student,Thermo and Fluid Dynamics

I completed my Licenciate examine in2002 and star ted in this project inNovember 2002, primarily working withnumerical simulation of spray formation.

Project descriptionThe project objectives are to investigatepossibilities and limitations for a spray guidedcombustion system (closed-spacing) usingdifferent types of injectors:

� High pressure multi-hole

� Air-assisted (Orbital)

Also, determining the design criteria for such acombustion system in regards to injectors,geometry and ignition energy is an importantobjective.

The project started in January 2002 and thefirst year of the project has been focused on sprayvisualisation in the spray chamber and in theoptical engine using the following measurementtechniques:

� AVL Visioscope™

� MIE/LIF

� LIEF (Laser Induced Exciplex Fluorescence)

� PDPA

Also, spray simulations using AVL Fire™ have beenperformed (figure 10).

This year (2003), the project will focus onstratified combustion using a variable spark plugpositioning system in the spray chamber as wellas in the optical engine. Furthermore, spraysimulations using AVL Fire™ and the LES codeFOAM™ will commence (figure 11).

Conclusions after the first yearFrom the LIEF images it is clear that there is avery large vapor concentration gradient in a multi-hole injector spray. This, in combination with thefact that there is almost no vapour without liquidinterference during injection, radically reducesthe possibilities to ignite the mixture duringinjection. However, it appears possible to use post-injection ignition due to high vapor concentrationwithout droplet interference after EOI.

It is essential to find a favourable spark plugposition near the spray. The optical engine (figure12 and 13) measurements suggest that it may bepossible to position the spark plug between twospray plumes to increase combustion stability andefficiency.

The simulations with the AVL Fire code showrelatively good agreement with experimentalresults. The simulations will provide a goodstarting point for the optical engine experiment.


Figure 10. Preliminary CFD (AVL Fire)calculations (to the left) compared withexperimental LIEF results showingrelatively good agreement. Left image:1.2 ms ASOI. Right image: 1.8 ms ASOI.

Figure 11. For SGDI combustionsystems it is of great impor tance toposition the spark plug in the vaporphase of the spray without liquidphase inter ference. LIEF (LaserInduced Exciplex Fluorescence) is ameasurement technique whichenables the visualization of the twophases separately. The vapor phaseconcentration is illustrated by the“height” of the spray (z-axis). Theliquid phase concentration is given bythe color scale.

Figure 12. AVL Visioscope imagesshowing the l iquid phase of theinjector spray in the optical engine.

Figure 13. The optical engine providesoptical access to the cumbustionchamber.


Laser Diagnostics of Dense Sprays

Arne Rosén, Professor

Michael Försth, Senior Scientist

Mats Andersson, Senior Scientist

Fredrik Persson, Ph.D. Student

Stina Hemdal, Project Student

Michael Försth, Researcher, Ph.D.Molecular Physics

Laser diagnostics is a general name formany different methods aimed at directlystudying what is actually taking place in acombustion chamber, such as in an enginecylinder for example.There are many different laser-diagnostictechniques that can be used for differentpurposes. One example is ramanspectroscopy for studying temperaturesand major species, such as O2, N2, andCO2 for example. Another example is laser-induced fluorescence that can be used tostudy the fuel, or maybe more importantlyminor radical species, such as OHmolecules and O atoms. The latter ispar ticularly impor tant for validatingnumerical models used in CFD-calculations.One problem with laser diagnostics is thatit is a relatively expensive way of working.Lasers, cameras, and optics are expensiveequipment. Additionally one need to modifythe engine that is to be studied in orderto obtain optical access, that is, one needto put windows on the engine. Thereforeit is an advantage to have laser diagnosticresearch within the framework of CERC,since the utilisation of the equipment willthen be maximised by using the techniquewithin the many various CERC-projects.

Stina Hemdal, Project Student,Molecular Physics

Personal Stina HemdalThis year I have concluded my diplomawork entitled “Development of CavityRingdown Spectroscopy for FlameAnalysis: Application to Calibration ofLaser-Induced Fluorescence”. Now I ama project student within the molecularphysics group and have recently startedto work within CERC. I am going to workwith laser diagnostics under thesuper vision of Mats Andersson andFredrik Persson

Optical, and in particular laser spectroscopic,techniques are currently the most straightforwardway to study molecules in the gas-phase. Theadvent of new lasers, which cover broadwavelength regions, short pulses, or that havenarrow bandwidths, advanced imagingtechniques and new types of detectors have beenvery important for the progress in molecularphysics. The access to such laser systems andmodern ICCD cameras has also openedpossibilities to develop new spectroscopictechniques for two-dimensional imaging ofconcentration of species and for studies of thedynamics of different processes. In the MolecularPhysics group we have used laser spectroscopyin a number of applications to study metal clustersand their properties, in particular to studycatalytic reactions. These studies have mostly beendone using Planar Laser Induced Fluorescence,PLIF, Second Harmonic Generation, SHG,combined with kinetic modeling using theChemkin package. A summary is given in thethesis of Michael Försth [14].

Our knowledge and experience in laserspectroscopy and combined with the use ofimaging techniques formed the basis for theextension of our research to problems incombustion engine research. The increase ininterest present of the use of direct fuel injectionbased on spray injectors in high-pressure Dieselengines and in direct injected Otto enginesformed challenging research problems. Theobjectives are to understand the spray behaviorin order to improve the performance of injectorsystems. The overall shape of a spray, and itspenetration length into the receiving media, canbe measured by means of photography, or laserbased techniques such as Mie scattering, or byLaser-Induced Fluorescence (LIF) of the fuel

vapor. Estimates of the soot volume mole fractioncan be obtained with Laser-Induced Incandescence,LII. Analysis of the internal properties of a spray,such as its breakup from bulk liquid into smallerdroplets, their size and number density, can beobtained using advanced image analysis of twodimensional images of Mie scattered light asdescribed in detail in the Annual Report (1999).Overviews of these studies are given in the thesesof Michael Försth [14] and Rafeef Abu-Gharbieh[15]. Results from these experimental studiescombined with CFD calculations of sprayformation give useful generic knowledge fordesign of spray injector systems.

In the last evaluation report of CERC theinternational advisers emphasized that differentlaser diagnostics methods will play an increasinglyimportant role in engine research, and thatsignificant effort should be devoted to expand thecurrent activities in laser spectroscopy, especiallyin spray research. According to theserecommendations we have continued thedevelopment of laser spectroscopy. CERC financedthe purchase of an intensified CCD camera fromLa Vision and a second camera was also purchasedby the Molecular Physics Group. Access to thesecameras has given us a good experimental set-upfor studies of sprays and for development of theOptical Two-Phase Diagnostics method describedbelow.

Studies have been done using Mie scatteringto determine the spray penetration and the angleof the ejected spray for different nozzles withreduced diameters [149]. In another project,imaging of the OH chemiluminescence (thenatural emission of light from OH-molecules)helped to determine the lift-off in diesel spraycombustion in the high temperature cell [150,151].

Figure 14. Orifice with conisityfactor k=3.0. Upper row ofimages is the liquid phase andthe lower row is the gas phaseof the injected fuel. From left toright is the following times afterstar t of injection: 0.10, 0.20,0.30, 0.50 and 1.00 ms. Theinjection pressure is 1350 barand the chamber condition is 50bar and 300 degrees Celsius [3].


Optical Two-Phase DiagnosticsThe liquid and gas phase of a spray can be studiedusing the Laser Induced Exciplex Fluorescencetechnique (LIEF) as introduced by Melton [152].The LIEF technique is used to obtain a spectralseparation of the fluorescence from the liquid fueland from the vapor fuel. In order to obtain thisinformation the fuel is doped with two organiccompounds, a monomer, M, and a so-called groundstate reaction partner, G. In the ground state thedopants are not attracted to each other. However,when M is excited by an external radiation sourcewith an accurate wavelength, the two moleculesreact during collisions and an exciplex (MG)* canbe formed. Because of the very different collisionfrequecy between the dopant molecules in thegas- and liquid phases, the exciplex will mainlybe produced and fluoresce in the liquid phaseand the monomers will have their emission inthe gas phase. The fluorescence from the exciplexis red shifted with respect to the fluorescencefrom the excited monomer, which means it has alonger wavelength and that it is possible toseparate the two phases from each other.

Ever since Melton introduced this method ithas been a challenge to find dopants which co-evaporate with the fuel and dopant concentrationsat which no or minimal monomer fluorescenceoccurs in the liquid phase. Another task is to finddopants with minimal fluorescence band overlapbetween the gas and liquid phase.

Studies of exciplex formation to determine themonomer and exciplex emission wavelengthshave been done at room temperature and ambientpressure using a cuvette in a Cary Eclipsefluorescence spectrophotometer. The differentdopants that have been tested can be found in[153]. Low boiling point fuel and dopants such

as Isooctane, Fluorobenzene and Triethylaminehave been used in exciplex studies in a highpressure -high temperature combustion chamberin the sGDI project [154] and n-Dodecane,Cyanonaphthalene and N,N-Dibutylaniline as highboiling point fuel/tracers in a diesel project [155].In these experiments the emission wavelengthfrom the liquid phase and the gas phase in thespray have been separately imaged on two ICCDcameras. To achieve this a filter was placed in frontof each camera. This filter transmits the desiredwavelength. Figure 15 shows the roomtemperature fluorescence emission from theliquid and vapor phase using 5% Naphthalene and5% N,N–Diethylaniline in Dodecane. These twodopants have almost the same boiling point andevaporation as Dodecane.

Figure 15. Emission wavelengths from a 5% Naphthalene and 5% N,N–Diethylanilinein Dodecane. The vapour phase originates from the monomer fluorescence andthe liquid phase can be tracked by the exciplex emission.


Therefore this combination can be aninteresting liquid- gas phase visualizer. A limitationof this method is that the fluorescence intensityis temperature and pressure dependent. Someexciplexes are so weakly bound that theydissociate at higher temperatures, withoutemitting light or having monomer fluorescencein the liquid phase. Other problems are quenchingwith oxygen and laser intensity attenuation if thesprays are too dense. If this occurs it is hard to doquantitative analysis from the LIEF method.However with a direct calibration it should bepossible to do quantitative measurements. Forexample, (Rotunno A. A., Winter M., Dobbs G. M. andMelton L. A., “Direct calibration Procedures ForExciplex-Based Vapor/Liquid Visualization of FuelSprays”, Combust. Sci. and Tech.. 1990. Vol. 71. pp.247-261) developed direct calibration proceduresfor liquid and vapor phases, by measuring thefluorescence intensity of a known amount ofliquid and vapor. With help of a high pressure/temperature cuvette we will hopefully, in the nearfuture, also be able to do these kinds ofquantitative calibrations.

Fredrik Persson, Ph.D. Student,Molecular Physics

I am working with laser diagnostics and withLaser Induced Exciplex Fluorescence (LIEF)in particular. It is interesting and challengingto study fundamental physics and then toapply spectroscopic research in engines.In spite of the fact that LIEF was used asearly as the middle of 80’s, a lot ofquestions remain to be solved before themethod is reliable. For example, what is thebehaviour at higher temperatures, can webe sure that it is only the liquid phase thatwe see and that there is no disturbingmonomer fluorescence?The advantage with using laserspectroscopy in combustion diagnostics ismainly that it is a non-intrusive method andthat it is possible to use the laser-diagnostictechnique for many different purposes likeRaman scattering and Laser Inducedfluorescence.

Cavity Ringdown Spectroscopy, CRDS, could bean additional method for calibrating the LIFintensity of the gas phase . CRDS is a highlysensitive multipass absorption method that isindependent of the light intensity. A light pulse iscaptured inside an optical cavity and the decayof the light is measured as a function of time bydetection of the small transmittance through theoutput mirror. The technique has been proven tobe a good tool for calibrating LIF images, forexamples in flames, achieving the number densityas function of the location in the flame [155] and(J. Luque, J. B. Jeffries, G. P. Smith, D. R. Crosley and J.J. Scherer, “Combined Cavity Ringdown Absorptionand Laser-Induced Fluorescence ImagingMeasurements of CN(B-X) and CH(B-X) in Low-Pressure CH4-O2-N2 and CH4-NO-O2-N2 Flames”).Figure 16 shows an atmospheric flame and itsCRDS calibrated LIF profiles of the OH numberdensity as function of the flame radius at differentheights in the flame.

Figure 16. An atmospheric flame and its CRDS calibrated LIF profiles giving the OH number density as function ofthe flame radius at dif ferent heights


The development of injection systems and theircontrol systems has led to more flexible systemsand possibility to control the injection better.Faster opening and closing of the injector as wellas shorter dwell times and not least betteraccuracy are now feasible. Multiple injection (MI)is one approach that, thank to this, now is possibleand indeed very interesting. Instead of only oneinjection per stroke, up to five or more shorterinjections can be used. This projects mainobjective is to study multiple injections, based onshort duration injections and small nozzle orificediameter. The importance of swirl and itscharacteristics will also be considered.

Short duration injectionIt has been shown with experiments in apressurised and heated spray chamber here atChalmers that short duration combustion occursin a soot free mode. This is due to the fact thatthe spray is dispersed in the air before it ignitesand thus the combustion occurs in a homogenousmode with overall low equivalence ratio and verylow emissions as a result.

Small orifice diameterWhen the nozzle orifice diameter is decreased,the spray characteristics are affected. The spraytip penetration gets shorter, the droplet size isdecreased and hence better atomization, fasterevaporating and better mixing are achieved.

Engine tests (heavy-duty DI diesel) has showedan essential reduction in HC emissions for all loadswith reduced orifice diameter. One reason to thisis the shorter spray tip penetration, which meansless wall impingement. Shorter ignition delay alsocontributes to HC reduction because it leads tothat less fuel becomes over lean. The tests alsoshowed that CO and soot emissions are reducedat lower loads. This is due to better mixing rateand hence shorter ignition delay. The fuelefficiency is generally better for smaller diametersfor all loads. The NOx-production is unfortunatelyhigher for a smaller orifice, as a result of bettermixing and hence shorter combustion duration[156].

Multiple injectionAs said earlier the two ideas described abovecould be combined in a multiple injection system.Up to five or more shorter injections are used inMI and one distinguishes three kinds of sub-injections; pilot, main and post injections. Eachmultiple injection can consist of one or more ofeach kind, e.g. pilot 1 – pilot 2 – main or pilot 1– pilot 2 – main – post 1 – post 2. Note that pilot1 and 2 not necessarily have to be similar. The

same for post 1 and 2. The two main propertiesfor each injection are; the dwell time, i.e. the timebetween two injections, and the injection time,i.e. the time under which the injection take place.It is obvious that a multiple injection can be variedto a great extent.

Why should multiple injections be utilised?There are some well-known and some less-known,more questionable advantages with MI. A MI

contributes to a reduction in heat release. Thiscontributes to a reduction in noise and NOx

without decreased engine efficiency. Multipleinjections can also be used to reduce sootemissions and specific fuel consumption.

However, there are also problems involvedwith MI. First, the injection system has itslimitations. Control of the dwell time andinjection time is extremely important. The rightamount of diesel has to be injected at the righttime. This depends both on the control systemand on the mechanical construction of theinjector. MI-systems has so far been limited by therather long dwell times in the Common Railsystems on the market. However, fast responsesystems with shorter dwell times are nowavailable on the market and with laboratoryequipment even shorter times can beenaccomplished. Fast opening and closing of a valvein a hydraulic system, an injector in an injectionsystem for example, results in hydraulic effects.Shock waves, going back and forth in the systemwith sonic speed, are created. This means that onecannot be sure that the conditions in the injectorare the wanted at the time for the injection if onedoes not know how to time the injection. This inturn means that the properties of the spray canbe affected. The dynamic of the system istherefore very important to investigate.

Not only is the condition in the injectorimportant but also the condition in thecombustion chamber. Figure 17 illustrates asequence of three pictures showing a secondinjected spray as it is going in to the trails of theprevious spray. This is a problem when dealingwith multiple injections because the oxygen isexpended in that area. The solution to thisproblem is swirl. With the right swirl each sub-injection will have optimal combustion condition.

Theoretical and Experimental Investigations of Combustion of ShortDuration Small Diameter Sprays in Diluted Air

Sven Andersson, Associate Professor,Project leader

Rickard Ehleskog, Ph.D. Student

I am a Ph. D. student at the departmentof Thermo and Fluid Dynamics since2002, and my research area is dieselengines, and especially short durationinjections and small orifice diameters. Mywork is mainly experimental but I will alsoinclude numerical simulations in order tolook into and understand cer tainphenomena.When tr ying to find out how a dieselcombustion system works it is mostimportant to have good understanding ofwhat is happening within the injectionsystem between the high-pressure pumpand the nozzle. The natural way to work isto star t investigating the elementar yunderlying characteristics andsystematically continue with experimentsthat are more complex where the final goalis full-scale engine tests. In my case, itmeans that the preliminary experimentsare about the dynamic behaviour of theinjection system and fur ther the spraycharacteristics. This knowledge will beuseful when starting with engine tests,to understand what is happening and whyit does.

Rickard Ehleskog, Ph.D. StudentThermo and Fluid Dynamics


The work in the projectSome measurements have already beencompleted in Chalmers’ high temperature, highpressure spray chamber. Exciplex measurements(the pictures in figure 17), and PDPA

measurements of diesel sprays (yet not evaluated).The Exciplex measurements shows theimportance to have a swirl in the combustionchamber as the subsequent spray is injected inthe trails of the former one where the oxygenconcentration is low.

The project will connect to and benefit fromother ongoing CERC-projects. From the project“Applied Combustion Diagnostics”, it is mainly theexperience about the spray characteristics andits behaviour in the cylinder that will be useful.

The knowledge from the project “Influence ofCavitation and Hydraulic Flip on Spray Formation,Ignition Delay, Combustion and PollutantFormation” about the flow in the nozzle and itsrelation to the spray formation is very importantfor this project. It is natural to investigate thedynamic of the injection system before lookingat the combustion, the swirl etc, since the sprayand its combustion highly depends on that. At themoment, measurements of fuel mass flow throughthe spray momentum are carried out using a sprayimpingement method developed in mentionedproject. By simultaneous measurements of the fuelmass flow through the nozzle, needle lift and fuelline pressure at several positions in the system itis possible to get an overview of the dynamic ofthe common rail system and its influence of thespray. Figure 18 shows what a multiple injectioncould look like.

Figure 18. The picture shows amultiple injection illustrated bythe fuel spray momentum (blackline) and the needle lift cur ve(green line). Present injectionconsists of two pilot and onemain injection.

After having looked at the injection system andthe behaviour within it the next step will be toinvestigate the spray, first without and later withcombustion. Finally, engine tests will take place.When starting to study the spray behaviour swirlwill have a central role, as it is believed to be anecessity to get the most out of multipleinjections. The combination of multiple injectionsand optimized swirl is an important feature of thisproject.

Figure 17. A sequence of threepictures showing a second injectedspray as it is going in to the trails ofthe previous spray.


Torque Sensors for Engine Applications

Mats Viberg, Professor, Projectleader

Bo Egardt, Professor

Jonas Sjöberg, Professor

Tomas McKelvey, Docent

Stefan Schagerberg, Ph. D Student

Stefan Larsson, PhD. Student

Ingemar Andersson, Ph. D Student

Figure 19. A scheme of the two par tsof the torque sensor project. To thelower right the signal processing par tand to the upper left the controlengineering part.

Stefan Schagerberg, Ph.D. Student,Signal Processing

The strive for improved ef ficiency andlowered emissions is a motivation forexploring new techniques, but the torquesensor also offers possibilities in the fieldsof driveability, onboard diagnostics,adaptivity and tuning. It offers a durablesensor, which measures the actual outputof the engine. Since it is crank angle resolvedit is also possible to retrieve information fromthe individual combustions.To enable the utilisation of the ever moresophisticated signal processing algorithmsdeveloped it is important to have a humanknowledge interface with disciplines statingproblems to solve. Otherwise we may endup with a state of the art toolbox but nocommon language enabling us to apply themon real problems. For the one posing theproblem, there is of course the benefit ofhelp in finding solutions and for both partiesnew ways of thinking.

Internal combustion engines are used in most oftoday's automobiles. Due to environmentalaspects more advanced engine control algorithmsare required in the future. To accomplish this, newsensor types are needed. One possibility is to usea crankshaft integrated torque sensor in order toretrieve information on the combustion process.

The torque sensor project started in 1998 andhas emerged from discussions between Chalmersand ABB on how to utilize a crankshaft integratedinstantaneous torque sensor for automotiveapplications, primarily internal combustionengine diagnosis and control. The torque sensorin question has been developed by ABB since1985. The project is performed as two PhDstudent projects within the framework of CERC,and is financed in part by ABB, Volvo CarCorporation, CERC and CHASE (Chalmers Centrefor Mechatronics and Systems Engineering). Theobjective is to investigate to what extentinstantaneous torque measurements can be usedto deduce information on the combustionprocess. The research is interdisciplinary andbased on a combination of physical modelingcontrol and system identification techniques.

The project is divided in two parts, (figure 19)where the first is focused on what informationcan be deduced from the sensor and generationof feedback signals. The second part is focusedon the control engineering aspects.

For the first part, an early attempt toreconstruct the cylinder pressure curve based on"black-box" system identification was made. Themethod works on a particular load and speed, butis difficult to generalize. Therefore, pressurereconstruction based on physical and semi-physical modeling has been developed [160].Using this technique, we have been able toestimate e.g. the peak pressure position (PPP)with an accuracy on the order of a degree. This isbelieved to be sufficient for the control purpose.


This project is interesting since it involveselectrical engineering into a mechanicalengineering perspective. The importance ofexchange in knowledge between differentdisciplines is something that should beencouraged far more than it is today in orderto be able to improve the existing solutionswith new ways of thinking. In this case we aretrying to find adaptive methods to be able toenhance, or even replace, some of the existingengine maps that are used and perhaps itwill even be possible to extend the degreesof freedom in the engine in order to make itmore efficient. Thus making the combustionengine more environmental friendly.

Stefan Larsson, Ph.D. Student,Control Engineering

The engine control field has been in myinterests since I first joined Mecel AB in1995, designing engine control systemsfor gasoline engines. My urge to learnmore about the combustion process itselfand how to control it, lead me to theresearch studies at Linköping University.In 2002 I finished my licentiate thesis onionization current modeling there. SinceMay 2002 I am a PhD student at Signalsand Systems.In the torque sensor project the goal is tounderstand the torque signal in such waythat it is possible to extract informationfrom it,usable for engine control. Inparticular, the focus is set on combustionparameters suitable for combustionphasing. For me it is interesting to learnabout the possibilities and limitations ofdif ferent sensor approaches, as for mein the case of torque and ionizationcurrent sensors.

Earlier in the project we have also studiedinformation retrieval based on crankshaftrotational speed and ionization measurements.The torque sensor has the advantage (as opposedto the more common crankshaft speedmeasurements) of measuring at a higherderivative level, thereby circumventing the needfor numerical differentiation of the signal. Thissignificantly increases the signal-to-noise ratio.The control part of the project is aimed towardmaximizing the output torque of the engine bymeans of adaptive control algorithms. Tounderstand the nature of the problem, a statisticalanalysis of the measurement data has beenundertaken [158]. We have then developed a"multivariable" control structure for

Figure 20. The engine that recently has been installed and instrumented. The torque sensor iscompletely integrated inside the engine.

Ingemar Andersson, Ph.D. Student,Signal Processing

simultaneously controlling spark advance andintake valve cam timing [157, 158]. The proposedcontrol principle will be evaluated during 2003.A multicylinder engine equipped with anintegrated torque sensor has been installed andinstrumented during 2001, see Figure 20. Themeasurement system consists of an applicationdeveloped in LabVIEW synchronized with anengine analysis software for the onboarddiagnostics.



Jerzy Chomniak, Professor Emeritus

Andreas Matsson, Ph.D. Student

Applied Combustion Diagnostics

Andreas Matsson, Ph.D. Student,Lic. Thermo and Fluid Dynamics./Volvo Powertrain AB

I started working for Volvo Powertrain in1997 as an industrial PhD being placedat the Department of Thermo and Fluiddynamic. My PhD work took off in March1998 when I spent a 6 months period atthe University of Minnesota in Minneapolis,hosted by Professor D.B. Kittelson at theDepartment of Mechanical Engineering. Atthe U o M I was doing some time resolvedparticle sampling and also particle sizemeasurements. The PhD work continuedwith engine testing at Chalmers where theeffect of non-circular nozzle hole havebeen investigated. I have also done someinvestigation of the effect of cavitation oncombustion and emissions in a dieselengine as well as in a high pressure hightemperature bomb with two colour method,Schlieren technology and high speedcamera.I think my project is important for thegeneral public and the industry because Iget to spend time to pertube a subjectthat will help understanding some of thecombustion phenomena in a dieselengine, so I can be a part of future enginedevelopment industry, passing even morestringent emission regulations.

The project has investigated the influence ofnozzle geometries on engine performance. With“geometry” is meant both non-cylindrical orificesaswell as hole diameter and different inlet radiiof the orifices. The hole diameter, jet velocity, sprayangle and turbulence level in the spray at the exit,determinds the following combustion and so theemissions. The reason for varying these parametersis that it could be a way of improving the air-fuelmixing process in order to decrease emissions. Itis therefore of interest to investigate the effect ofthe different parameters. The characteristics ofthe diesel engine unfortunately tends to trade offthe regulated emissions (particulate and NOx)against one another, so that one emission isdecreased as the other one is increased. Findinga technical solution that reduces both emissionsor at least one while the second remainsunchanged, over most of the engine operatingrange without fuel penalties, is of great interest.

During the year 2002 experiments in the enginehave been performed. In the first set of experimentsthe effect of nozzle inlet conditions on fuelconsumption and emissions was investigated, bycomparing different grade of hydro grinding. Thiswas a continuation of last year testing (2001) andthe use of endoscope technique was applied withthe intention to further investigate the effects ofhydro grinding on the spray pattern. Further, theoptical cylinder head was finally tested, and wasused to investigate the flame pattern of the non-circular holes. A couple of days were also devotedto investigate the effect of increased f lowdisturbance in the nozzle sac. This was done bygrinding down the needle tip and placing a 1 mmball bearing ball in the nozzle sac.

The results from the first set of experimentsinvestigated the effect of hydro grinding showsimproved emission trade off curves for highergrade of hydro grinding. There were no obviousdif ferences in the spray pattern and thephotographic technique was too coarse for themeasurements. A final test is planned during 2003to further study the effect of hydro grinding bylooking at the effect of maximum dischargecoefficient of the nozzles and using 2-colourmethod for f lame temperature and sootevaluation.

The results from the non-circular nozzle holesshows that the combustion is delayed for non-circular holes, and the effect is stronger for higheraspects ratios. The expected reduction of smoke/soot emissions hasn’t been measured from thenon-circular holes, instead the trend is the opposite.The reason for the delayed combustion is believedto be caused by the flame-wall interaction. This isbased on the images taken with the optical cylinderhead where the time of flame – wall interactioncoincided with the abrupt changes in rate of heatrelease, Figure 21. The results were presented atSAE fuel and lubes conference, autumn 2002 [161].

The ball in the sac was only tested at low loadto minimize the risks. Images of the spray patternshowed a slightly bushier spray, but suprisinglyno major differences in emission and fuelconsumption where found.

During 2002 the paper ”Combustioncharacteristics of diesel sprays from equivalentnozzles with sharp and rounded inlet geometries”,Combustion Science and Technology” was acceptedfor publication [162]. This paper was done incollaboration with the CERC-project “Influence ofcavitation and hydraulic flip on spray formation,ignition delay, combustion and pollutant formation”.

Figure 21. Flame wall interaction at9 and 11 CAD after star t of injectionfor the non-circular holes.


Influence of Cavitation and Hydraulic Flip on Spray Formation, IgnitionDelay, Combustion and Pollutant Formation


Jerzy Chomiak, Professor Emeritus

Lionel C. Ganippa, Ph.D. Student

Lionel Christopher Ganippa,Ph.D. Student, Lic. Thermo andFluid Dynamics

I am working in the field of cavitation inDiesel nozzles and its influence on sprayformation and combustion. Investigationswere per formed on scaled-up Diesel likenozzles and in real size Diesel nozzles tounderstand the nozzle internal flow processand its influence on spray formation andcombustion (in real size nozzles). Experimentsper formed on scaled-up nozzles understeady flow atmospheric conditions revealedthat the liquid jet is very sensitive to thecavitation distribution with the nozzle hole,which even resulted in an asymmetric jetdue to unsymmetrical distribution ofcavitation within the nozzle.However, due to the adversities of timescales, length scale, geometric similarities,flow, test fuels, nozzle temperatures etc. Iper formed experiments in a highpressure, high temperature combustioncell using real size nozzles with differentlevels of honing grades at high injectionpressures. From the nozzles used in theexperiments it was obser ved that thespray angles, spray penetration, ignitiondelay and flame volumes are almost thesame for the two nozzles (0 and 20 % HG)having strongly dif ferent initial turbulenceand cavitation level. It seems that theentrainment of air into the spray throughthe momentum exchange between theinjected fuel and the air appears to beimpor tant. Thus it could be concludedsaying that the Diesel spray behaviour istotally controlled by its momentum andthe internal nozzle flow structure does notmatter as long as it does not change thejet momentum.

In this project cavitation effects on atomisationwere investigated through spray impingement,scale-up transparent nozzles and by looking at thehydro grinding effects in a real size Diesel nozzleon combustion. The spray impingement method,developed within the project, through which thetime resolved fuel flow out of a nozzle is obtained,is now in use as a popular research tool.

Scaled-up transparent nozzles were used toinvestigate the flow within the nozzle hole andto link its effect on the jet emerging from thenozzle flow. Cavitation distribution within the

cross-flow nozzle has a strong influence on thespray pattern.

It even causes the jet atomisation to changefrom symmetric to asymmetric, with atomising jeton the side where there is more cavitation andnon-atomising jet on the side where there is lesscavitation. This experimental result has led forthto a collaboration with AVL in validating their spraybreak-up model, [163,164]. The comparison oftheoretical and experimental results is shown inFigure 22.

Figure 22. Comparison of modelling results with experiments.

In order to study the reason for spray asymmetry,cavitation structures within the nozzle at thecorresponding flow were processed as shown inFigure 23 to develop understanding of the

Figure 23. Edge traces of the internalnozzle flow (cavitation structures) andthe near-nozzle spray dispersion.

internal flow mechanisms. A conceptual model[165] for spray asymmetry was proposed, Figure24, as follows:


Case (a): The fluid particle P and Q on either sidesof the nozzle hole inner experience very similartransverse flow perturbation and these transversefluctuations will be partly damped as P and Qmove toward the outlet and the jet is symmetrical.

Case (b): Particle P, lies on the side of the holewhere there is less cavitation and particle Q, onthe side of hole where there is shedding ofcavitation clouds. Shedding and transversepulsations of the cavity within the nozzle holeinduce transverse motions to nearby liquidparticles like P and Q. The transverse motion ofparticle P will be very similar to that discussed incase (a) as long as the particle is in the cavitation-free environment. While the fluid particle Qexperiences both liquid as well as cavitationcloud. The equilibrium of the fluid particle Q isaffected, due to the transverse motion caused bythe shedding of cavitation cloud, turbulence aswell as the re-entrant jet. Whenever particle Q isin contact with the shed cavitation cloud thecontact surface is more or less like a free surface.The transverse motions acting on the particle Qin the hole exit plane causes particle Q expandsmore on to the right of the hole exit resulting inasymmetry of the jet whenever there is ashedding event.

Case(c): The cavitation sheet attached to thefluid acts as a free surface. The transverse motionsgained by the particle P or Q will survive untilthe exit on the cavity side and the transversemotion of the fluid particle Q is not damped onthe free surface. When the particle Q exits thenozzle hole the transverse motions are such thatthere is a greater tendency for the particle Q tomove towards the free surface side as there is noimpedance to the transverse motions, producedupstream by cavity pulsations. Thus the particleQ is pushed along with the expanding cavitationfilm which results in a dispersion of the jet onthis side a complete asymmetry of the jet.Although the cavitation was shown to beimportant for cross flow scaled-up nozzles it is

Figure 24. Conceptual model for theorign of asymmetric spray atomization.

not so for single hole axisymmetric nozzles. Thiswas shown in high pressure, high temperaturecombustion chamber studies.

Equivalent nozzles were selected such that themomentum rates of the spray from both nozzles,as determined by the spray impingement werethe same. This was obtained by increasing theorifice diameter of the nozzle with 0 % HG tocompensate for the higher friction losses andlower discharge coefficient of the nozzle. Thedifferences in discharge coefficient indicate thatthe f lows inside the nozzles have differentturbulence and cavitation levels. In spite of thestrong differences in internal flow, the sprays,which had the same momentum rate, behavedidentically. In particular, the spray dispersion,penetration, ignition delay, combustiontemperatures, flame volumes, soot concentrationand liftoff distances were almost the same forboth sprays. The conclusion is that Diesel spraycombustion in axisymmetric sprays is controlledby its momentum and the internal nozzle flowstructure does not matter, as long as it does notchange the fuel jet momentum orgeometry, [166].


HumanresourcesDuring this period, Chalmers University of Technology engaged eleven Ph.D.students, seven of whom are at the Department of Thermo and Fluid Dynamics,one is at the Department of Physics (Molecular Physics Group) and three areat the Department of Signals and Systems (Signal Processing Group and ControlEngineering Group).The senior research project personnel associated with the activities areequivalent to approximately five full-time positions. The total workloadprovided by the participating companies corresponds to approximately onefull-time position.Personnel working at CERC during 2002 were:

Karl-Göran Andersson Director (CERC; upto August 2002)Sivert Hiljemark Director (CERC; from August 2002)Jerzy Chomiak Professor Emeritus (Internal Combustion Engines)Erik Olsson Professor Emeritus (Thermo and Fluid Dynamics)Ingemar Denbratt Professor (Internal Combustion Engines)Arne Rosén Professor (Molecular Physics)Bo Egardt Professor (Control EngineeringMats Viberg Professor (Signal Processing)Jonas Sjöberg Professor (Machine and Vehicle Systems)Sven Andersson Associate Professor (Internal Combustion Engines)Andrei Lipatnikov Associate Professor (Internal Combustion Engines)Valeri Golovithev Associate Professor (InternalCombustion Engines)Tomas McKelvey Associate Professor (Signal Processing)Mats Andersson Senior Scientist (Molecular Physics)Petter Dahlander Researcher, Ph. D (Internal Combustion Engines)Savo Gjirja Researcher (Internal Combustion Engines)Torbjörn Sima Research Engineer (Internal Combustion Engines)Rolf Berg Research Engineer (Internal Combustion Engines)Niklas Nordin Ph.D. Student (Internal Combustion Engines)Tao Feng Ph.D. Student (Internal Combustion Engines)Lionel C. Ganippa Ph.D. Student (Internal Combustion Engines)Mikael Skogsberg Ph.D. Student (Internal Combustion Engines)Michael Försth Ph.D. Student (Molecular Physics)Fredrik Persson Ph.D. Student (Molecular Physics)Stefan Schagerberg Ph.D. Student (Signal Processing)Stefan Larsson Ph.D. Student (Control Engineering)Ronnie Lindgren Ph.D Student (Internal Combustion Engines)Rickard Ehleskog Ph. D Student (Internal Combustion Engines)Ingemar Andersson Ph. D Student (Signal Processing)Andreas Mattson Industrial Ph.D. Student (Internal Combustion Engines)Stina Hemdal Project Student (Molecular Physics)

A number of representatives from the member industries are also indirectlyinvolved in CERC activities working with the project leader as part of expertgroups within each project. All persons working on projects have signedspecial secrecy agreements.

Management of CERC

Within Chalmers University ofTechnology, CERC is an independentunit with its own budget and accounting.CERC’s activities are governed by itsown board of directors appointed bythe President of Chalmers University ofTechnology in consultation with themember companies.

During the year Director Karl-Göranretired after a succesful period as theHead of CERC and Sivert Hiljemark wasappointed as his successor with theoverall responsibility of coordinationwithin the centre. During 2002 theboard consisted of the chairman,three academic members and fiverepresentat ives f rom membercompanies and one memberrepresenting STEM:

Jan-Crister Persson

(Chairman of the Board).

Tommy Björkqvist

SAAB Automobile Power train AB.

Jerzy Chomiak

Chalmers University of Technology.

Derek Crabb

Volvo Car Corporation

Ingemar Denbratt


Bernt Gustafsson

Swedish Energy Agency (STEM).

Urban Johansson

Scania CV AB.

Arne Rosén


Sören Udd

Volvo Power train AB.

Research at CERC is pursued asdescribed in this annual repor t withproject leaders repor ting their resultsdirectly to the CERC board.


Table 2. Actual contributions from participants 2002 (KSEK)

Revenues Total Cash ”In kind”

ABB Automation Products AB 1 080 760 320

Aspen Petroleum AB 100 100 0

SAAB Automobile AB 900 500 400

Scania CV AB 490 400 90

Den norske stats oljeselskap s.e. 173 123 50

Volvo Power Train AB 1 590 550 1 040

AB Volvo Penta 120 100 20

Volvo Car Corporation 1 350 1 000 350

STEM 6 000 6 000

Chalmers Univ. of Technology 7 439 867 6 572

Commission 54 54

TOTAL 19 296 10 454 8 842

BUDGET 19 660 10 260 9 400

Table 3. Expenses at Chalmers 2002 (KSEK)

Paid by ChalmersPersonnel expenses Total CERC “in kind”

Project director 507 507 0

Ph.D. Student 3 593 2 633 960

Professor 1 571 571 1 000

Research engineer 2 268 1 884 384

Engineer 400 400 0

External consultants 292 292 0

Equipment and Development

Computers 29 29 0

Software (Program) 0 0 0

Material 208 208 0

Testing (rig. etc.) 3 000 1 000 2 000

Instruments 598 48 550

Miscellaneous equipment 160 160 0

Miscellaneous

Travel 204 204 0

Overhead 3 895 2 819 1 076

Premises 650 50 600

Unspecified 0 0 0

Salaries 8 631 6 287 2 344

Equipment and Development 3 995 1 445 2 550

Miscellaneous 4 749 3 073 1 676

TOTAL 17 375 10 805 6 570

Finances during theperiod 2001-2003During 2001-2003, the budget following the agreement between thethree parties, STEM/ Industry/CTH given in Table 1 was established.Some of the revenues from the participating companies are “effortsin kind”.Table 2 shows actual input of cash respectively “efforts in kind” forthe participating companies during the year 2002.In Table 3, the cost of activities at Chalmers during 2002 are given,distributed by cost categories.Table 4 shows a summary of the project expenses for the year 2002.

Table 1. Total budget for 2001-2003 period (KSEK)

Revenues 2001 2002 2003

STEM 6 000 6 000 6 000

SAAB Automobile Powertrain AB 1 000 1 000 1 000

Scania CV AB 500 500 500

Volvo Power Train AB 1 600 1 600 1 600

Volvo Car Corporation 1 250 1 250 1 250

Statoil A.S. 150 150 150

Aspen Petroleum AB 150 150 150

ABB Automation Products AB 760 760 760

AB Volvo Penta 150 150 150

Chalmers Univ. of Technology 7 650 7 650 7 650

TOTAL 19 660 19 660 19 660

*

***

**

***

Comments on “In kind” contributions:Development of a new torque sensor.

Industrial Ph. D student and equipment.

Equipment for DI-project and consultations.***

**

*

See Table 3 for details.


Table 4. Summary of expenses 2002 (KSEK)

Spray-guided gasoline directInjection (sGDI)

Control of engines by a torque-sensor

Applied combustion diagnostics

Optical dual phase diagnostics

Modeling of spray formation,ignition, and combustion ininternal combustion engines

Influence of cavitation andhydraulic flip on spray formation,ignition delay, combustion andpollutant formation

Combustion of shor t durationsmall diameter spray

Administration *

TOTAL

Project:

ChalmersSalaries

ChalmersEquipm.

ChalmersMiscellan.

ChalmersTotal

ChalmersBudget

ChalmersCash

IndustryTotal

IndustryBudget

OverallTotal

OverallBudget

1 812 1 208 1 060 4 080 4 495 2 960 550 550 4 630 5 045

1 060

490

636

2 000

1 195

610

828

8 631

484

445

371

50

176

180

1 081

3 995

556

240

228

890

634

315

826

4 749

2 100

1 175

1 235

2 940

2 005

1 105

2 735

17 375

2 100

1 175

1 235

2 562

2 007

1 610

2 550

17 480

1 360

575

835

1 810

1 275

955

1 035

10 805

520

1 000

0

80

120

0

0

2 270

450

0

1 000

80

100

0

0

2 180

2 620

2 175

1 235

3 020

2 125

1 105

2 735

19 645

2 550

2 175

1 235

2 642

2 107

1 356

2 550

19 660

* Including “In kind” CTH equipment


References1. Lipatnikov, A.N. and Chomiak, J. “Developing

Premixed Turbulent Flames: Par t I. A Self-SimilarRegime of Flame Propagation”, Combustion Scienceand Technology, 162, pp. 85-112, 2001.

2. Lipatnikov, A.N. and Chomiak, J. “DevelopingPremixed Turbulent Flames: Part II. Pressure-DrivenTransport and Turbulent Diffusion”, CombustionScience and Technology, 165, pp. 175-195, 2001.

3. Lipatnikov, A.N. and Chomiak, J. “Modeling ofPressure and Non-Stationary Ef fects in Spark IgnitionEngine Combustion: A Comparison of DifferentApproaches”, SAE Transactions, Vol. 109, Section 3,Journal of Engines, 2001 (SAE Paper 2000-01-2034).

4. Lipatnikov, A.N. and Chomiak, J. “Turbulent FlameSpeed and Thickness as Tools for Multi-DimensionalComputations of Premixed Turbulent Combustion”,Progress in Energy and Combustion Science, 28, pp.1-73, 2002.

5. Lipatnikov, A.N. and Chomiak, J. “Highly TurbulentCombustion and Flame Quenching”, First BiennialMeeting and General Section Meeting of theScandinavia-Nordic Section of the CombustionInstitute, Gothenburg, April 18-20, 2001, pp.7-12.

6. Lipatnikov, A.N. and Chomiak, J. “Are SteadyPremixed Turbulent Flames Fully Developed?”,Proceedings of the Third Pacific Conference onCombustion ASPACC 2001, Seoul, June 24-27,2001, pp.83-86.

7. Lipatnikov, A.N. and Chomiak, J. “Towards Evaluationof Turbulent Flame Speed”, The Fifth InternationalSymposium on Diagnostics and Modeling ofCombustion in Internal Combustion Engines, Nagoya,July 1-4, 2001. CD.

8. Lipatnikov, A.N. and Chomiak, J. “Simulations ofPremixed Turbulent Stagnation Flames with a FlameSpeed Closure Model”,18th International Colloquiumon the Dynamics of Explosion and Reactive Systems,July 29 - August, 3, 2001, Seattle, Washington. CD.ISBN# 0-9711740-0-08.

9. Lipatnikov, A.N. and Chomiak, J. “A Method forEvaluating Fully Developed Turbulent Flame Speed”,Internal Combustion Engines, Proceedings of the 5-thInternational Conference ICE 2001, September 23-27, 2001, Capri-Naples. CD CNR - Istituto Motori.Paper SI2 - 2001-01-046.

10. Lipatnikov, A.N. and Chomiak, J. “Testing of PremixedTurbulent Combustion Models for Gas Turbine andEngine Applications”, Combustion and theEnvironment, XXIV Event of the Italian Section of theCombustion Institute, September 16-19, 2001, S.Margherita Ligure. pp. VIII.7-VIII.10.

11. Lipatnikov, A.N. and Chomiak, J. “Are PremixedTurbulent Stagnation Flames Equivalent to FullyDeveloped Ones?” Proceedings of the SecondMediterranean Combustion Symposium, 6-11January, 2002, Sharm El-Sheikh, Egypt, Eds. by M.S.Mansour and M. Kamel, Vol. 1, pp. 169-171, 2002.

12. Lipatnikov, A.N. and Chomiak, J. “Towards Evaluationof Turbulent Flame Speed”, The Fifth InternationalSymposium on Diagnostics and Modeling ofCombustion in Internal Combustion Engines,COMODIA2001, Nagoya, July 1-4, 2001, p.31.

13. Lipatnikov, A.N. and Chomiak, J. “A Method forEvaluating Fully Developed Turbulent Flame Speed”,Internal Combustion Engines, Abstracts of the 5-thInternational Conference ICE 2001, September 23-27, 2001, Capri-Naples. CNR - Istituto Motori, p.89,2001.

14. Michael Försth, “Laser Diagnostics and ChemicalModeling of Combustion and Catalytic Processes”.Ph.D.Thesis,Dep. of Experimental Physics, ChalmersUniversity of Technology, 2001.

15. Rafeef Abu-Gharbieh, “Laser Sheet Imaging andImage Analysis for Combustion Research”.Ph.D.Thesis, Dep. of Experimental Physics, ChalmersUniversity of Technology, 2001.

16. Golovitchev, V.I., Nordin, N., “Detailed ChemistrySpray Combustion Model for the KIVA Code”, The11th International Multidimensional Engine ModelingUser’s Group Meeting at the SAE Congress, Detroit,March 4, pp. 1-6 (2001).

17. Golovitchev, V.I., Nordin, N., and Chomiak, J., ”OnLength of Flame Lift-off and Combustion ZoneStructure of DI Diesel Sprays”, First Biennial Meetingof the Scandinavian-Nordic Section of theCombustion Institute, Goteborg, April 18-20, pp. 145-150 (2001)

18. Rente, T., Golovitchev, V.I., and Denbratt, I.,“Numerical Study of Pilot Injection and Ignition of n-Heptane Diesel Spray”, First Biennial Meeting of theScandinavian-Nordic Section of the CombustionInstitute, G¨ oteborg, April 18-20, pp. 13-18 (2001)

19. Rente, T., Golovitchev, V.I., and Denbratt, I.,“Numerical Study of n-Heptain Diesel Spray Auto-ignition at Different Level of Pre-ignition Turbulence”,The 5th International Symposium on Diagnostics andModeling in Internal Combustion Engines,COMODIA2001, Nagoya, July 1-4 (2001)

20. Tao, F., Golovitchev, V.I., and Chomiak, J.,“Application of Complex Chemistry to Investigate theCombustion Zone Structure of DI Diesel Sprays underEngine-like Conditions”, The 5th InternationalSymposium on Diagnostics and Modeling in InternalCombustion Engines, COMODIA2001, Nagoya, July 1-4 (2001).

21. Rente, T., Golovitchev, V.I., and Denbratt, I., “Effectof Injection Parameters on Auto-ignition and SootFormation in Diesel Sprays”, SAE Paper 2001-01-3687 (2001).

22. Golovitchev, V.I., “Revising ”Old” Good Models:Detailed Chemistry Spray Combustion ModelingBased on Eddy Dissipation Concept”. The 5thInternational Conference Internal CombustionEngines, ICE2001, Capri-Naples, September 23-27(2001).

23. Golovitchev, V.I., and Chomiak, J., “Structure ofCombustion Zone and Soot Formation in Lifted DIDiesel Spray Flames”, The 24th Event of the ItalianSection of the Combustion Institute Combustion andEnvironment, S.Marghareta Ligure, September 16-19, pp. IV-7/IV-10 (2001).

24. Golovitchev, V.I., and Chomiak, J.,” NumericalModeling of High Temperature Air ”Flameless”Combustion”, The 4th International Symposium onHigh Temperature Air Combustion and Gasification,Rome, November 26-30 (2001).

25. Stefan Larsson, “Literature Study on ExtremumControl”. Teknisk rapport, R007/2001. Control andAutomation Laboratory, Department of Signals andSystems, Chalmers University of Technology,Göteborg, Sweden, 2001.

26. Stefan Larsson, “Torque Optimization in CombustionEngines / A Feasibility Study”. Teknisk rapport,R009/2001 Control and Automation Laboratory,Department of Signals and Systems, ChalmersUniversity of Technology, Göteborg, Sweden, 2001.

27. Andreas Matsson, “Diesel particulate matteremissions: Background, characterization andreduction problems”. Lic Thesis 2000. Thermo andfluid dep. Chalmers University of Gothenburg.

28. Andreas Matsson, “The ef fect of nozzle inletconditions on fuel consumption and emissions of aheavy duty diesel engine”. JSAE 20015345.

29. Lionel Christopher Ganippa, Andreas Matsson, SvenAndersson, and Jerzy Chomiak: “CombustionCharacteristics of Diesel Sprays from Nozzles withSharp and Rounded Inlet Geometries” submitted forcombustion symposium 2002.

30. Lipatnikov, A.N. and Chomiak, J. “Turbulent FlameSpeed and Thickness as Tools for Multi-DimensionalComputations of Premixed Turbulent Combustion”,submitted to Progress in Energy and CombustionScience, 2000.

31. Lipatnikov, A.N. and Chomiak, J. “Testing DifferentModels of Premixed Turbulent Flame Development”.Unsteady Combustion and Interior Ballistics.Lectures of the III International Workshop, June 26-30, 2000, Saint Petersburg, Russia, Vol. I, pp.70-80,2000.

32. Lipatnikov, A.N. and Chomiak, J. “Transition fromGradient to Counter-Gradient Transport in DevelopingPremixed Turbulent Flames,” Open Meeting onCombustion. XXIII Event of the Italian Section of theCombustion Institute. Lacco Ameno, Ischia, May 22-25, 2000. CD.

33. Lipatnikov, A.N. and Chomiak, J. “Counter-GradientDiffusion in Premixed Turbulent Flames: an OldProblem Revisited,” Chemical Physics of Combustionand Explosion Processes. XII Symposium onCombustion and Explosion. Proceedings. IPKhPhRAN, Chernogolovka, Moscow region, Russia. Vol. 1,pp. 185-186, 2000.

34. Lipatnikov, A.N. and Chomiak, J. “Transition fromGradient to Counter-Gradient Transport in DevelopingPremixed Turbulent Flames”, 28th InternationalSymposium on Combustion. Abstracts of Work-in-Progress Poster Presentations. The CombustionInstitute, Pittsburgh, p.167, 2000.

35. Lipatnikov, A.N. and Chomiak, J. “Testing DifferentModels of Premixed Turbulent Flame Development,”Unsteady Combustion and Interior Ballistics.International Workshop, June 26-30, 2000, SaintPetersburg, Russia. Proceedings. pp.36-37.

36. Wallesten, J. and Chomiak, J. “Investigation of SparkPosition Effects in a Small Pre-Chamber on Ignitionand Early Flame Propagation”, SAE Paper 2000-01-2839, 2000.

37. Sandquist, H., Denbratt, I., Owrang, F., and Olsson,J., “Influence of fuel Parameters on DepositFormation and Emissions in a Direct InjectionStratified Charge SI Engine”, SAE SpecialPublications, vol. 1629, pp. 207 - 218, SAE Paper2001-01-2028, 2001.

38. Sandquist, H., Karlsson, M., and Denbratt, I.,“Influence of Ethanol Content in Gasoline onSpeciated Emissions from a Direct Injection StratifiedCharge SI Engine”, SAE Special Publications, vol.1584, pp. 221 - 229, SAE Paper 2001-01-1206, 2001.

39. Sandquist, H. and Denbratt, I., “Cycle-Resolved NOMeasurements in the Exhaust Port of a DirectInjection Stratified Charge SI Engine”, Paper in“Direkteinspritzung im Ottomotor III”, expert verlag,Renningen, Germany, pp. 345 - 361, 2001.

40. Sandquist, H. “Influence of Fuel Parameters onDeposit Formation and Emissions in Direct InjectionStratified Charge SI Engine”. Ph. D. Thesis, Dep. ofThermo- and Fluid Dynamics, Chalmers University ofTechnology.

41. Sandquist, H., Karlsson, M., and Denbratt, I.,“Influence of Ethanol Content in Gasoline onSpeciated Emissions from a Direct Injection StratifiedCharge”, to be presented at 2001 SAE WorldCongress, March 5-8, Detroit, Michigan, USA, 2001.

42. Lionel C. Ganippa, G. Bark, S. Andersson, J.Chomiak, ”Structure of Cavitation and its Effect onSpray Pattern in a Single Hole Diesel Nozzle”, SAEInternational Spring Fuels & Lubricants Meeting,Orlando (FL), May 2001.

43. Lionel C. Ganippa, G. Bark, S. Andersson, J.Chomiak, ” Comparison of Cavitation Phenomena inTransparent Upscale Diesel Nozzles”, CAV2001, TheFourth International Symposium on Cavitation,Pasadena (CA), June 2001.

44. Lundström, D, and Schagerberg, S., “MisfireDetection for Prechamber SI Engines Using IonSensing and Rotational Speed Measurements”, SAESpecial Publications, vol. 1586, pp. 79 - 84, SAEPaper 2001-01-0993, 2001.

45. Abu-Gharbieh, R., Persson, J., Försth M., Rosén A.,Karlström A., Gustavsson T., “Compensation methodfor attenuated planar laser images of optically densesprays”, Applied Optics 39, 1260 (2000).

46. Michael Försth, “Laser Diagnostics of DenseSprays”, Nordic Symposium on Combustion, LundApril 27, 2000.

47. Arne Rosén, Michael Försth, and John Persson,Rafeef Abu-Gharbieh and Tomas Gustavsson “LaserDiagnostics of Dense Sprays”, EdinburghConference, 2000.

48. Michael Försth, “Turbulence and Fractal Analysisusing Wavelets”, Project work.

49. Michael Försth and Hui Lui, “Wavelet MultiresolutionAnalysis of Spray Images from a Diesel Injector”, 3rdPacific Symposium on Flow Visualization and ImageProcessing, March 2001.

50. Pär Bergstrand and Michael Försth and IngemarDenbratt “Investigation of Diesel spray injection intohigh pressure conditions with reduced nozzle orificediameter”, 2001 JSAE Spring Convention inYokohama, Japan, May 2001.

51. G. Hanehöj, “Laser measurements on a directinjection two stroke Husqvarna engine”.

52. Golovitchev, V.I., and Chomiak, J., ComprehensiveChemical Mechanism of Soot Formation for DieselSpray Combustion Modeling, XXII Event of the ItalianSection of the Combustion Institute, Lacco Ameno,Ischia, May 22-25 (2000).


53. Golovitchev, V.I., Nordin, N., Jarnicki, R., andChomiak, J., 3-D Diesel Spray Simulations Using aNew Detailed Chemistry Turbulent Combustion Model,SAE Paper 200-01-1891 (2000).

54. Tao, F., Some Physical and Chemical Aspects of SootFormation and Oxidationin Spray CombustionModeling, Thesis for the degree of Licentiate ofEngineering, Chalmers University of Technology (2000).

55. Tao, F., Golovitchev, V.I., and Chomiak, J., Self-Ignition and Early Combustion Process of n-HeptaneSprays Under Diluted Air Conditions: NumericalStudiesBased on Detailed Che-mistry, SAE Paper2000-01-2931 (2000).

56. Nordin, N., Complex Chemistry Modeling of DieselSpray Combustion, Thesis for the degree of Doctor ofEngineering, Chalmers University of Technology (2000).

57. Jarnicki, A. Teodorczyk, V. Golovitchev, and J.Chomiak, Numerical Simulation of Spray Formation,ignition and Combustion in a Diesel Engine, UsingComplex Chemistry Approach, The 26th InternationalConference on Internal Combustion Engines ”KONES2000”, September 10-13, 2000, Naleczow, Poland.

58. Golovitchev, V.I., and Chomiak, J., Simple DetailedChemistry Approach for Turbulent Spray CombustionModeling, 28th (International) Symposium onCombustion, The Combustion Institute, Pittsburgh,Abstracts 5-B14 of W-in-P session, p. 450 (2000).

59. Golovitchev, V.I., Revising ”Old” Good Models:Magnussen Turbulent Eddy Dissipation ConceptFormal Substantiation, Interpretation and Applicationto Detailed Chemistry Spray Combustion in ICE.Topical Meeting ”On Modeling of Combustion andCombustion Processes”, Abo/Turky, Finland, 15- 16November, (2000).

60. Lipatnikov, A.N. and Chomiak, J. “A Self-SimilarRegime of Premixed Turbulent Flame Development,”submitted to the 28th Symposium (International) onCombustion.

61. Lipatnikov, A.N. and Chomiak, J. “Dependence ofHeat Release on Progress Variable in PremixedTurbulent Combustion,” Proceedings of theCombustion Institute, 28, in press.

62. Lipatnikov, A.N. and Chomiak, J. “Modeling ofPressure and Non-Stationary Ef fects in Spark IgnitionEngine Combustion: A Comparison of DifferentApproaches”, SAE Paper 2000-01-2034.

63. Lipatnikov, A.N. and Chomiak, J. “Transient andGeometrical Effects in Expanding Turbulent Flames”,Combustion Science and Technology, in press.

64. Lipatnikov, A.N. and Chomiak, J. “A Numerical Studyof the Turbulent Flame Speed Development AfterIgnition,” Joint Meeting of the British, German andFrench Sections of the Combustion Institute.Abstracts. 18-21 May 1999, Nancy, France, pp. 65-67, 1999.

65. Lipatnikov, A.N. and Chomiak, J. “Burning Velocity atStrong Turbulence: Role of Flame Geometry andTransient Effects”, Proceedings of the MediterraneanCombustion Symposium - 99, Eds. by F. Beretta. pp.1038-1049, 1999.

66. Lipatnikov, A.N. and Chomiak, J. “A Numerical Studyof Turbulent Flame Speed Development in theSpherical Case,” 17th International Colloquium onthe Dynamics of Explosion and Reactive Systems,July 25-30, 1999, Heidelberg, Germany. CD ISBN 3-932217-01-2. Paper 026.

67. Chomiak, J. and Lipatnikov, A.N. “On MechanismsContributing to the Bending of Turbulent BurningVelocity Curve,” Joint Meeting of the British, Germanand French Sections of the Combustion Institute.Abstracts. 18-21 May 1999, Nancy, France, pp. 9-11,1999.

68. Lipatnikov, A.N. and Chomiak, J. “Effects ofTurbulence Length Scale on Flame Speed: aModelling Study,” Engineering Turbulence Modellingand Measurements 4, Eds. by W. Rodi and D.Laurence, Elsevier, Amsterdam, pp.841-850, 1999.

69. Wallesten, J. “Modeling of Flame Propagation inSpark Ignited Engines”. Licentiate thesis. 1999.

70. Sandquist, H. and Denbratt, I. “Comparison ofHomogeneous and Stratified Charge Operation in aDirect Injection Spark Ignition Engine”, presented atThe 15th Internal Combustion Engine Symposium,Seoul, Korea, 13-16 July, 1999.

71. Sandquist, H. and Denbratt, I. “Influence of FuelVolatility on Cycle-Resolved Hydrocarbon Emissionsfrom a Direct Injection Spark Ignition Engine”,presented at the Gasoline Direct Injection EngineCongress, Munich, Germany, 16-17 November, 1999.CERC – Annual Report 2000 22.

72. Sandquist, H. and Denbratt, I., “Sources ofHydrocarbon Emissions from a Direct InjectionStratified Charge Spark Ignition Engine”, SAE SpecialPublications, vol. 1547, pp. 101 - 111, SAE Paper2000-01-1906, 2000.

73. Andreas Matsson, Lisa Jacobsson, Sven Andersson,”The Effect of Elliptical Nozzle Holes on Combustionand Emission Formation in a Heavy Duty DieselEngine ”, SAE 2000, Detroit, Paper 2000-01-1251.

74. Moh’d Abu-Qudais, Andreas Matsson, DavidKittelson, ”Combination of Methods forCharacterisation Diesel Engine Exhaust ParticulateEmissions”, accepted for publication in JSME journal.

75. R. Abu-Gharbieh, J. L. Persson, M. Försth, A. Rosén,A. Karlström, T. Gustavsson, “A CompensationMethod for Attenuated Planar Laser Images ofOptically Dense Sprays, ”Applied Optics (2000), in press.

76. M. Försth, “Laser Diagnostics and Modeling of theCoupling between Heterogeneous Catalytic and Gas-Phase Oxidation of Hydrogen”, Licentiate thesis (1998).

77. Abu-Gharbieh R. “Laser Sheet Imaging and ImageAnalysis Applied to Spray Diagnostics”, Lic. Thesis,Technical Report No. 317L, Chalmers University ofTechnology, (1999).

78. M. Försth, P. C. Hinze, P. Miles, ”One dimensionaltemperature measurements in an IC engine usingspontaneous Raman scattering”, Article inpreparation.

79. Golovitchev, V.I., Nordin, N., Chomiak, J., andNishida, K., Evaluation of ignition quality of neat DMEat Diesel-like conditions. Paper published in theProceedings of the International Conference ICE99:Internal Combustion Engines: Experiments andModeling, Capri- Naples, September 12-16 (1999).

80. Tao, F., Golovitchev, V.I., and Chomiak, J., NumericalModeling of Auto-Ignition, Combustion, and SootFormation in n-Heptane Sprays in a High PressureConstant-Volume Chamber. Paper published in theProceedings of the International Conference ICE99:Internal Combustion Engines: Experiments andModeling, Capri- Naples, September 12-16 (1999).

81. Golovitchev, V.I., Tao, F., and Chomiak, J., NumericalEvaluation of Soot Formation Control at Diesel-LikeConditions by Reducing Fuel Injection Timing, SAEPaper 99FL-388 (1999).

82. Golovitchev, V.I., Nordin, N., Detailed Chemistry Sub-Grid Scale Model of Turbulent Spray Combustion forthe KIVA code, Paper published in the Proceedings ofthe ASME 1999 Fall Technical Conference. Session”In-cylinder Flow Combustion Measurements andModel-ing”, October 16-20, Ann Arbor, Michigan, USA(1999).

83. Golovitchev, V.I., Nordin, N., KIVA 3-D SimulationsUsing a New Detailed Chemistry Diesel SprayCombustion Model, Paper published in theProceedings of the Workshop ”Combustion Modelingin I.C.E.”, December 14-15, Cassino, Italy (1999).

84. B. van Norel, R. I. le Grand, ”How to measure the airentrainment in diesel sprays”, Internal report 99/10,Department of Thermo and Fluid Dynamics, ChalmersUniversity of Technology, 1999.

85. Lionel C. Ganippa, S. Andersson, J. Chomiak,”Transient Measurements of Discharge Coefficientsof Diesel Nozzles”, SAE paper 2000-01-2788.

86. S. Gjirja, “Engine Design Optimization, a PracticalTechnology for Optimum Per formance and Emissionsof an Ethanol Fueled Engine”, Paper No 97EL008,International Conference Proceedings, 30th ISATA,Florence, Italy,1997.

87. S. Gjirja, E. Olsson, “Ether as Ignition Improver andIts Application on Ethanol Fueled Engine”, InternskriftNr 97/15, Thermo & Fluid Dynamics, ChalmersUniversity of Technology, 1997. Also published asKFB-Meddelande 1997:38.

88. S. Gjirja, E. Olsson, A. Karlström, “Ether Fumigation,a New Alternative for the Neat Ethanol Diesel Engine”, Paper No 98EL008, International ConferenceProceedings, 31st ISATA, Clean Power Sources &Fuels. Special Innovative Conference: IntelligentTransportation Systems, Düsseldor f, Germany, 1998.

89. S. Gjirja, E. Olsson, A. Karlström, “Investigations onMethanol Engine with DME Fumigation”, Paper99CPE007, 32 nd ISATA, June 14-17, Vienna, Austria,1999.

90. H. Armbruster, J. Van Gunsteren, S. Stucki, E. Olsson,S. Gjirja, “On-board conversion of alcohols to ethersfor fumigation in diesel engine s”, Paper atInternational Symposium on Alcohol Fuels, ISAF XIII,in Stockholm 3-6 July 2000.

91. Lipatnikov, A.N., J. Wallesten, J. Chomiak, and J.Nisbet, “Computations of Combustion in Bombs andan SI-Engine Using a Turbulent Flame Speed ClosureModel and Modified FIRE Code”. ComputationalTechnologies for Fluid/Thermal/Chemical Systemswith Industrial Applications, Vol. II, ASME, New York,pp. 199-206, 1998.

92. Lipatnikov, A.N., Wallesten, J., and Nisbet J.,“Testing of a Model for Multi-DimensionalComputations of Turbulent Combustion in SparkIgnition Engines”, COMODIA 98 - The FourthInternational Symposium on Diagnostics andModeling of Combustion in Internal CombustionEngines}, JSME, Kyoto, pp. 239-244, 1998.

93. Wallesten, J., Lipatnikov, A.N., and Nisbet J.,“Turbulent Flame Speed Closure Model: FurtherDevelopment and Implementation for 3-D Simulationof Combustion in SI Engine”, SAE Paper 982613,1998.

94. Wallesten, J., Lipatnikov, A.N., Chomiak, J., andNisbet J., “3D Simulation of Combustion in SI EngineUsing a Turbulent Flame Speed Closure Model”.Expose över förbränningsforskningen i Sverige,Chalmers Institute of Technology, Gothenburg, 21-22October 1998, p.62.

95. Lipatnikov, A.N. and Chomiak, J., “Effects ofTurbulence Length Scale on Flame Speed: AModelling Study”, submitted to 4th InternationalSymposium on Engineering Turbulence Modelling AndMeasurements, Corsica, France, May 24-26, 1999.

96. Lipatnikov, A.N. and Chomiak, J., “Randomness ofFlame Kernel Development in Turbulent GasMixture”, SAE Paper, 1998.

97. Lipatnikov, A.N. and Chomiak, J., “Lewis NumberEffects in Premixed Turbulent Combustion and HighlyPerturbed Laminar Flames”, Combustion Scienceand Technology, 1998, in press.

98. Lipatnikov, A.N. and Chomiak, J., “Burning Velocityat Strong Turbulence: Role of Flame Geometry andTransient Effects”, submitted to MediterraneanCombustion Symposium, Antalya, Turkey, June 20-25, 1999.

99. Håkan Sandqvist, Ingemar Denbratt, ÅsaIngemarsson, Jim Olsson, “Influence of FuelVolatility on Emissions and combustion in a directinjection Spark Ignition Engine”. SAE-paper 982701.SAE Fall meeting San Fransisco. 1998.

100. Åsa Ingemarsson, “Emissions from combustion andpyrolysis from liquid and solid fuels investigatedusing GC/MS and GC/FTIR/FID”. Licentiate thesis1998. Institutionen för fysikalisk kemi, Chalmerstekniska Högskola.

101. Åsa Ingemarsson, Jörgen Pedersen, Jim Olsson,“Sampling from n-Heptane/air flames with on-lineGC/FID and GC/MS. Two dif ferent samplingstrategies”. Internal report 1997-03-24.

102. Åsa Ingemarsson, Jörgen Pedersen, Jim Olsson,“Emissions analysis GC/MS on an Ethanol/EtherFuelled engine”. Internal report 1997-06-23.

103. Åsa Ingemarsson, Jörgen Pedersen, Jim Olsson,“Summary of GC/MS measurements on aMethanol/DME engine”. Internal Report 1998-06-17.

104. Åsa Ingemarsson, Jörgen Pedersen, Jim Olsson,“Identification of key compounds in gasoline andoxygenate flame combustion”. Internal report 1997-04-08.

105. Åsa Ingemarsson, Jörgen Pederssen, Jim Olsson,“Emisionsanalys av oxygenatbränslen. Specielltetanol/dietyleter blandningar. Metod för snabbanalys med mikro GC”. Internal report 1996 10-25.

106. Åsa Ingemarsson, Jörgen Pederssen, Jim Olsson,“Emissionsanalys av oxygenatbränslen. Specielltetanol/ diethyleter blandningar. Metod för GC/MSanalys med GCD”. Internal report 1997-03-24.

107. Jörgen Pedersen, Åsa Ingemarsson, Jim Olsson,“Oxidation of Rapeseed Oil, Rapeseed Methyl Ester(RME) and Diesel Studied With GC/MS”.Chemosphere 1998.

108. Pär Bergstrand och Mattias Marklund, “Design andconstruction of a spray rig for investigation ofcavitation in diesel injectors”, MSc thesis,Depar tment of Thermo and Fluid Dynamics,Chalmers University of Technology, 1998.

109. Matsson, A., “Different Methods ForCharacterization of Diesel Engine ExhaustParticulate Emissions”, Presented at the CERCseminar, Chalmers, Göteborg, 1999-03-03.


Editor..............................Sivert Hiljemark

Layout......................................Hagal AB

Print...........................Litorapid Media AB

Göteborg - Sweden 2003

110. Golovitchev, V.I., Nordin, N., and Chomiak, J., “NeatDimethyl Ether: Is it Really Diesel Fuel of Promise?”.SAE Paper 982537 (1998).

111. Golovitchev, V., and Chomiak, J., “Evaluation ofIgnition Improvers for Methane Autoignition”. Journ.Combust. Sci. and Tech., vol. 135, pp. 31-47 (1998).

112. Nordin, N., Golovitchev, V.I., and Chomiak, J.,“Computer Evaluation of DI Diesel Engine Fueledwith Neat Dimethyl Ether”. Proceedings of the 22ndCIMAC, 18-21 May, Copenhagen, vol.2, pp. 408-421(1998).

113. Nordin, N., “Numerical Simulations of Non-SteadySpray Combustion Using the Detailed ChemistryApproach”. Thesis for the degree of Licentiate ofEngineering, Chalmers University of Technology(1998).

114. Gjirja, S., Olsson, E., Karlström, A., Ingemarsson, Å.,Berg, R., ”Alcohol Engines with Ether as IgnitionImprovers. Literature Review and Suggestions”.Internskrift Nr 96/27, Thermo & Fluid Dynamics,Chalmers University of Technology, 1996.

115. Gjirja, S., Olsson, E.,”Ether as Ignition Improver andIts Application on Ethanol Fueled Engine”,Internskrift Nr 97/15, Thermo & Fluid Dynamics,Chalmers University of Technology, 1997. Alsopublished as KFB-Meddelande 1997:38.

116. Golovitchev, V., Nordin, N., Chomiak, J., ”Modelingof Spray Formation, Ignition and Combustion inInternal Combustion Engines”. Publication Nr 98/1,Thermo & Fluid Dynamics, Chalmers University ofTechnology, 1998.

117. Gjirja, S., Olsson, E., ”On-Board ManufacturedEthers as an Ignition Improver for Alcohol Engines.Reference Test with Poly-Ethylene-Glycol (PEG)Ignition Improver”. Internskrift Nr 98/9, Thermo &Fluid Dynamics, Chalmers University of Technology,1998.

118. Gjirja, S., Olsson, E., ”Onboard Manufactured Ethersas an Ignition Improver for Alcohol Engines. Effectsof the DME Fumigation on Methanol EnginePer formance and Emission Levels”. Internskrift Nr98/10, Thermo & Fluid Dynamics, ChalmersUniversity of Technology, 1998.Systems,Düsseldorf, Germany, 1998.

119. Gjirja, S., Olsson, E., Karlström, A., ”Considerationson Engine Design and Fuelling Technique Effects onQualitative Combustion in Alcohol Diesel Engines”.SAE International Fall Fuels and Lubricants Meeting,Paper 98FL-322, San Fransisco, USA, October 19-22, 1998.

120. CERC – Combustion Engine Research Center”Annual Report 1996”. Chalmers University ofTechnology, http://www.tfd.chalmers.se/CERC/(1996).



123. Lipatnikov, A.N. and Chomiak, J., “A Simple Model ofUnsteady Turbulent Flame Propagation”, SAE Paper972993 (1997).

124. Lipatnikov, A.N. and Chomiak, J., ”Modeling ofTurbulent Flame Development in Spark IgnitionEngines”, Proceedings of 3rd InternationalConference on Internal Combustion Engines:Experiments and Modeling, Instituto Motori, Naples,pp.75-82 (1997).

125. Lipatnikov, A.N. and Chomiak, J., ”Simulations of theEffect of Strong Perturbations on Laminar Flames”,16th International Colloquium on the Dynamics ofExplosions and Reactive Systems. August 3-8,1997. Conference Proceedings, University of Miningand Metallurgy, Cracow, pp. 406-409 (1997).

126. Lipatnikov, A.N. and Chomiak, J., ”Modeling ofTurbulent Flame Propagation”, Chalmers Universityof Technology, Göteborg (1997). 1217. Lipatnikov,A.N. and Chomiak, J. ”Lewis Number Effects inPremixed Turbulent Combustion and HighlyPer turbed Laminar Flames”, submitted to Combust.Sci. and Tech. (1997).

128. Lipatnikov, A.N. and Chomiak, J., ”Minimum IgnitionEnergy and Randomness of Flame Development inTurbulent Gas”, XVth International Symposium onCombustion Processes, Zakopane, September, 8-12, 1997. Abstracts Polish Academy of Sciences, p.20 (1997).

129. Burgdor f, K. and Karlström, A., ”Using Multi-RateFilter Banks to Detect Internal Combustion EngineKnock”. SAE Paper 971670 (1997).

130. Karlström, A., Lundström, D. and Viberg, M., ”KnockLocalization in Internal Combustion Engines UsingMultiple Pressure Sensors”. Chalmers University ofTechnology, Techn. Report-CTH-TE-66 (1997).

131. Lundström, D., Karlström, A., “Transient Identificationusing a Fractional Derivative Model”. Accepted forpublication at the European Control ConferenceECC99, August 31 – September 3, Karlsruhe (1999).

132. Andersson, S., Wallesten, J., ”Ethanol and Ether(DEE) Spray Experiments – PDA Measurements andVideo Imaging”, Report No 97/23, Dept. of Thermoand Fluid Dynamics, Chalmers University ofTechnology (1997).

133. Persson, J., Försth, M., Rosén, A., ”Spray diagnostics970401”, Report No 98/1, Dept. of Physics (theMolecular Physics Group), Chalmers University ofTechnology (1997).

134. Golovitchev, V. and Nordin, N., ”FIRE code, v6.2b:Droplet Evaporation Models”. Chalmers University ofTechnology, Dept. of Thermo and Fluid Dynamics,Technical Report 97/22 (1997).

135. Nordin, N. and Golovitchev, V., ”Numerical Evaluationof n-Heptane Spray Combustion at Diesel LikeConditions”. The 7th Internat. KIVA Users Meeting atthe SAE Congress, February 23, 1997, Detroit, Bookof Abstracts, pp.1-5 (1997).

136. Golovitchev, V. and Nordin, N., ”Numerical Evaluationof Dual Oxygenated Fuel Setup for DI DieselApplication”. SAE Paper 971596 (1997).

137. Golovitchev, V., Nordin, N. and Chomiak, J.,”Modeling of Spray Formation, Ignition andCombustion in Internal Combustion Engines”. AnnualReport (1997).

138. Golovitchev, V., “Micro-Mixing Time Definition in theEddy Dissipation Concept”, Combustion Science andTechnology, accepted for publication in 2002.

139. Lipatnikov, A.N. and Chomiak, J. “Turbulent FlameSpeed and Thickness:Phenomenology, Evaluation,and Application in Multi-Dimensional Simulations”,Progress in Energy and Combustion Science, 28, No.1, pp. 1-73, 2002.

140. Lipatnikov, A.N. and Chomiak, J. “Turbulent BurningVelocity and Speed of Developing, Curved, andStrained Flames”, Proceedings of the CombustionInstitute, 29, in press.

141. Wallesten, J., Lipatnikov, A.N., and Chomiak,J.“Modeling of stratified combustion in a DI SI engineusing detailed chemistry pre-processing”,Proceedingsof the Combustion Institute, 29, in press.

142. Golovitchev, V. and Chomiak, J. “Numerical Modelingof High-Temperature Air Flameless Combustion”,Proceeding of the 6th European Conference INFUB,Lisbon, Portugal, Eds. by Reis, Ward and Leuckel, Vol.1, pp. 325-340, 2002.

143. Golovitchev, V., “Towards Universal Model ofTurbulent Combustion”, Ninth InternationalConference on Numerical Combustion, April 7-10,2002, Sorrento, Italy. pp. 324-325.

144. Golovitchev, V. and Chomiak, J. “Analysis of MainAssumptions Underlying the Revised EDC Approachfor Combustion Modeling”, Proceeding ofScandinavian-Nordic Section of the CombustionInstitute, September 10-11, 2002, Trondheim, Norway.

145. Tao, F.,and Chomiak, J. “Numerical Investigation ofReaction Zone Structure and Flame Lift-Off of DIDiesel Sprays with Complex Chemistry”, SAE Paper2002-01-1114.

146. Lipatnikov, A.N., Chomiak, J., and Wallesten, J.“Modeling of Turbulent Flames Expanding underElevated Pressures in Combustion Bombs andInternal Combustion Engines”, Ninth InternationalConference on Numerical Combustion, April 7-10,2002, Sorrento, Italy. pp. 155-156.

147. Wallesten J., Lipatnikov, A.N., and Chomiak, J.“Simulations of Fuel/Air Mixing, Combustion, andPollutant Formation in a Direct Injection gasolineEngine”, SAE Paper 2002-01-0835.

148. Lipatnikov, A.N. and Chomiak, J. “Transient andCurvature Effects when Defining Burning Velocity andSpeed of Premixed Turbulent Flames”, EngineeringTurbulence Modelling and Measurements 5, Eds. byW. Rodi and N.Fueyo, Proceedings of the 5thInternational Symposium on Engineering TurbulenceModelling and Measurements, Mallorca, Spain, 16-18September, Elsevier, 2002, pp. 853-862.

149. Pär Bergstrand, Michael Försth and Ingemar Denbratt,“Investigation of Diesel Spray Injection into HighPressure Conditions with Reduced Nozzle OrificeDiameter”, JSAE 20015324.

150. Pär Bergstrand, Michael Försth and Ingemar Denbratt,“The Influence of Orifice Diameter on Flame Lift-OffLength”, ILASS-Europe 2002.

151. Ganipa, L, manuscript in preparation.

152. Fredrik Persson, Michael Försth, and Arne Rosén, “ASurvey of Model Fuel Mixtures Suitable for Exciplex-Spectroscopy for Liquid/Vapor Visualization”,Proceedings of the 18th Annual Conference on LiquidAtomization & Spray Systems, ILASS Europe, (2002).

153. Mikael Skogsberg, manuscript in preparation.

154. Pär Bergstrand, Fredrik Persson, Michael Försth andIngemar Denbratt, ”A Study of the Influence of NozzleOrifice Geometries on Fuel Evaporation using Laser-Induced Exciplex Fluorescence”, JSAE 20030217(SAE Paper 2003-01-1836).

155. Stina Hemdal “Development of Cavity RingdownSpectroscopy for Flame Analysis: Application toCalibration of Laser-Induced Fluorescence” MasterThesis 2002.

156. Bergstrand P., “Towards th End of the DieselDilemma”, Licentiate Thesis Chalmers 2001.

157. Larsson S.: “Engine Control Using Torque Sensors”.Control Meeting, Linköping University, June 2002.

158. Larsson, S.: "A Statistical Analysis of Pressure andTorque Measurements in aSI-engine. Workingdocument. Chalmers, July 2002.

159. Larsson, S.: "SI-Engine Spark Advance Control UsingTorque Sensors". Draft submitted to SAE 2003.

160. Schagerberg, S. and T. McKelvey: "InstantaneousCrankshaft Torque Measurements - Modeling andValidation”. SAE paper, 2003. To appear.

161. Andreas Matsson, Sven Andersson ”The Effect ofNon-Circular Nozzle Holes on Combustion andEmission Formation in a Heavy-Duty Diesel Engine ”SAE 2002-01-2671.

162. Lionel Christopher Ganippa, Andreas Matsson, SvenAndersson, and Jerzy Chomiak ”Combustioncharacteristics of diesel sprays from equivalentnozzles with sharp and rounded inlet geometries”,Combustion Science and Technology, accepted forpublication.

163. Berg, E.v, Alajbegovic, A., Greif, D., Poredos, A.,Tatschl, R., Winklhofer, E., Ganippa, L.C.(2002)Primary Break-Up Model for Diesel Jets Based onLocally Resolved Flow Field in the Injection Hole,Annual Conference on Liquid Atomization & SpraySystems-Europe, Sep. 9-11 Zaragosa.

164. Berg, E.v, Edelbauer, W., Tatschl, R., Volmajer, M,Kegl, B., Alajbegovic, A. and Ganippa, L.C. (2003)Validation of a CFD Model for Coupled Simulation ofNozzle Flow, Primary Fuel JetBreak-up and SprayFormation. ASME Internal Combustion EngineConference, ICES2003-643, May 11 - 14, Salzburg.

165. Ganippa, L.C., Bark, G., Andersson, S., and Chomiak,J: (2003a) “Cavitation: a contributory factor in thetransition from symmetric to asymmetric jets in cross-flow nozzles” Experiments in Fluids. (accepted forpublication).

166. Ganippa, L.C., Matsson, A., Andersson, S. andChomiak, J. (2003b) “Combustion Characteristics ofDiesel Sprays from Equivalent Nozzles with Sharp andRounded Inlet Geometries”, Combustion Science andTechnology, (in press).

The Competence Centre in Internal Combustion Engines(Combustion Engine Research Center – CERC) was establishedat Chalmers University of Technology in co-operation withSwedish engine manufacturers and the Swedish Board ofTechnical and Industrial Development (NUTEK) in 1995.1997 the co-ordination is transferred to the Swedish NationalEnergy Administration. The aim of the centre is to strengthenthe activities concerning the relevant basic industrial researchassociated with Internal Combustion Engines.

CERC concentrates on research aiming for reductions both offuel consumption and engine exhaust emissions. The projects atthe centre include both experimental validation of models andsystems and new concepts associated with alternative fuels.Furthermore, new diagnostic tools are used in engine research.Several projects concentrate on different types of sprayformation, spray diagnostics and flame propagation. Strongcompetence in thermodynamics, mass and heat transport,kinetics and measurement techniques will be built up.

CERC

CERCChalmers University of Technology

SE-412 96 Göteborg

Sweden

Telephone +46 (0)31-772 1820

Fax +46 (0)31-18 09 76

E-mail [email protected] www.tfd.chalmers.se/CERC/

annual report 2002 - thermo · laser diagnostics of dense sprays theoretical and experimental...

Documents