Report of
an ISAB (International Scientific Advisory Board) Member
Choongsik Bae, KAIST, Korea
26 September 2012
on the occasion of KCFP 2012 Meeting, 13-14 Sep. 2012
The KCFP center members are congratulated for having developed the relevant
engine technologies meeting future needs with well-organized research system even
under tough environment with reduced budget and having great meeting in 2012.
The meeting venue, Kulturen was an impressive site with well-concentrated
atmosphere surrounded by abundance of cultural flavor.
Overall Observation
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It was observed that each member gave presentation with confidence coming from
mature experience and abundant database, which reflects the status of KCFP.
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The center is very strong in research and social activities with two decades of
history , and its subjects are concentrated well onto PPC and other subjects such as
Gendies, gas engines and waste heat recovery.
The leadership of Professor Bengt Johansson is still manifested and strengthened
through the organizing the research themes aiming for a clear target of high
efficiency advanced combustion system.
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Research themes and achievements
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The research projects are well organized and focused. The achievement of each
project is phenomenal and more concrete than year ago.
Emphasis of PPC aiming to high efficiency is attracting industry and global interests.
This has been successful over a decade and still a role model of world-wide
research groups and their efforts.
Model, simulations are independently well developed and validated with in-house
experimental data. This reflects the synergetic collaboration between members
inside KCFP.
Globalization
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The center is very active in international collaboration with renowned research group
such as Sandia National Lab. This kind of global collaboration could be promoted
by inviting more international partners.
KCFP members have been observed to do the leading role in various international
events especially academic conferences.
Industrial Collaboration
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The center has an extensive list of industry membership with some changes this
year, but still with consistent participation and support.
Well-defined research could be developed through the proposal from industry.
Detailed comments on each project, based on the presentation in KCFP 2012
Meeting on 13-14th, September 2012.
In general, presentations were clear and well organized to show the progress, contribution
and vision of each research project.
1. KCFP introduction
Director, Bengt Johansson
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A couple of industry members, SAAB and SAGI, dropped their support, though these
were compensated by new members, Borg Warner, Loge, Dantec and Senfusion.
2. Partially Premixed Combustion, PPC in Heavy duty engine ;
PPC with Ethanol Fuel in Comparison to Conventional Fuels
Mengquin Shen *****
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This work focused on (1) understanding combustion process of PPC in a heavy
duty engine and (2) better control to achieve high efficiency with low emissions,
especially with new experimental set-up showing mature and confident organization.
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Combustion processes of PPC involve premixing of fuel and air to avoid soot
formation and the low combustion temperature to avoid NOx formation, which were
analyzed through heat-release rates
Control was conducted to the parameters such as fuel injection, inlet conditions,
lambda & EGR
Experiments were carried out logically from near-stoichiometric PPC testing the
benefit of Ethanol in comparison to conventional fuels followed by an investigation
on O2 concentration effect on PPC with high dilution
Near-stoichiometric PPC showed highest efficiency at around 11 bar IMEP condition
up to 55%, and ethanol proved soot-less combustion without substantial efficiency
loss. 120o injection (umbrella or included) angle provided the optimal configuration
for best mixing for PPC.
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Higher O2 concentration(less EGR) generally gives shorter ignition delay and less
premixed combustion, while the efficiency of gasoline operation showed decreasing
efficiency tendency and that of diesel and ethanol showed contradictory trends
depending load conditions.
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Optical engine work at the next stage is expected to give very interesting results.
3. Partially Premixed Combustion, PPC – HD, Simulations ;
Potential ESC13 Performance of a Multi-Cylinder Heavy Duty PPC Truck
Engine. System Simulations based on Single Cylinder Experiments
Martin Tunér****
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Tactical development step-by-step is quite reasonable ; Single-cylinder GT-Power
model developed and calibrated with experiment data (4 operating points)  Singlecylinder GTP model expanded to cover ESC13  Multi-cylinder GTP model based
on single-cylinder GTP model + Scania production engine data
Selection of RoHR (rate of heat release) is very reasonable in that PPC combustion
show much faster combustion than the conventional compression-ignition
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combustion.
Turbo-charger needs validation and supplementary operation on the model.
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Systematic parametric study was proved to be achievable through the simulation,
which could make synergetic role.
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Practical high-end technologies such as twin turbocharger and non-EGR are
expected to give interesting and useful results at the future work.
4. PPC light duty;
Partially Premixed Combustion - Light Duty, The Low Load Limit
Patrick Borgqvist ***
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NVO technique was re-addressed focusing on rebreathing strategy
Rebreathing is inevitable due to the collision between piston and valves, which is
compatible to late valve closing.
It is recommended to consider the modification of piston top to avoid valve collision
in realizing late valve closing. Pressure fluctuation caused by rebreathing actuation
was not observed though some literatures reported it in multi-cylinder engines.
Neverthless these must be kept in mind for practical application
Investigation of the Mixture Preparation
Combustion using kHz fuel tracer PLIF
Zheming Li**
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in
Partially
Premixed
PLIF system installed on an optical single cylinder engine was presented, though the
definitions of signal are not yet well established. It is expected that this freshman
student develop the diagnostics technique with more effort in the future.
5. PPC – model ;
Numerical study of combustion and emissions in a PPC engine using
finite-rate chemistry and CCM
Mehdi Jangi***
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CCM (Chemistry Coordinate Mapping) method was developed and applied to a
single cylinder engine.
It is recommended to find a way to present the methodology, process of modeling
and results and validation, in an easy-to-understand way
Intrinsic models and OpenFOAM application is a substantial achievement for KCFP,
Lund.
LES of mixing and combustion in a light duty PPC engine
Rickard Solsjö****
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LES was utilized to see the effects of swirl and injection strategies on the fuel
distribution and subsequent combustion process.
The models were validated by KCFP and relevant third body’s results, which was
proved to be reasonable and showed future needs to develop.
6. Partially Premixed Combustion, PPC – Fuel Aspects, PPC-Fuel;
Analysis of Surrogate Fuels Effect on Ignition Delay and Low
Temperature Reaction during Partially Premixed Combustion
Hadeel Solaka*****
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Fuel effect on PPC was well built up on the initial finding of one year ago that
gasoline PPC in Volvo D5 shows lower emission characteristics than diesel
operation.
Parametric study was systematically conducted by combining some practical and
surrogate fuels, such as n-heptane, alcohol, toluene and iso-octane to cover wide
range of fuel qualities.
This gives a set of valuable findings on fuel effect on main features of PPC
operation ; relationships between RON, aromatic/alcohol content, ethanol content,
oxygen concentration and combustion phase, ignition delay, LTR
Application strategy in PPC is expected to be completed in right stage based on this
successful database set.
7. Partially Premixed Combustion, PPC – Combustion Control, PPCControl ;
Principal Component Analysis and Neural Network Modeling for
Prediction of Engine Emissions from Cylinder Pressure Data
Maria Henningsson***
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Data-mining approach was carried out to exploit the high-dimensional data provided
by cylinder-pressure sensors, through PCA and neural network modeling.
It needs more progress to be generally applicable in the future.
8. Generic Diesel Engine project, GenDies
Introduction
Öivind Andersson
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Gendies is a ten year-old project build a knowledge base for industry, mainly aiming
to investigate soot emissions
Air-Entrainment in Wall-Jets Using SLIPI in a Heavy-Duty Diesel Engine
Clement Chartier***
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Presenter’s appearance is appreciated even after he got enrolled in the industry after
graduation
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air entrainment was investigated in wall jets under engine-realistic conditions using
fuel-tracer (acetone) LIF and SLIPI close to the bowl-wall, as a function of injection
pressure and interjet angle.
Interjet angle in the literatures need to be defined and presented in easy-tounderstand way
PIV supplement is recommended to observe entrainment
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Lubricity enhancing additive was added by 0.5%, which should be clarified in its side
effects, though it is not manifested substantially so far.
LES Study of Jet-Wall Interaction in an Optical Heavy Duty Diesel
Engine
Richard Solsjö****
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Modelling and numerical simulation were carried out and validated with Sandia data,
which is fulfilling the need for spray-lead combustion analyses.
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Prediction of lift-off fits well and shows a vision for spray-led combustion simulation
in advanced engines.
Effects of Jet-Jet Interactions on the Liquid Fuel Penetration in an
Optical Heavy-Duty DI Diesel Engine (Include a few slides on the
LabView update)
Guillaume Lequien***
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Control of experimental event and visualization was done for jet-jet interaction
measurement.
Calculation or image processing technique should be improved for better resolution
of spray imaging
Development of a Laser Extinction Setup for Soot Measurements
Yann Gallo***
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Laser extinction method was applied and applied for burner system for the moment.
672nm could be applied in engine experiment. Two wavelength measurement could
provide the size of soot as well.
It needs improvement for better soot measurement.
9. Gas engine ;
Pre-chamber spark plugs – further heat release analysis and
applicability of Ionization Current Sensing technique
Ashish Shah***
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Pre-chamber spark plug is suggested as an alternative ignition techniques to extend
dilution lean limit with EGR, reduce NOx and increase the maximum operating load.
Some more explanation is needed for the interpretation of ion current intergral.
The physical meaning of cyclic variation and cylindrical variation and importance of
each need to be identified in more logical way.
10. Waste heat recovery;
Prakash Narayanan***
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PPC with more EGR(>50%) was found to give more waste heat recovery chance,
estimated by IPSEpro, a commercial package.
This needs a validation through experiment in long term
It was a great pleasure to be in the meeting and to observe the much more improved
research activity in KCFP.
Choongsik Bae
Professor,
Department of Mechanical Engineering
Director, Combustion Engineering Research Center
KAIST (Korea Advanced Institute of Science and Technology)
Chair, Combustion Implementing Agreement, IEA (International Energy Agency)
373-1 Kusong, Yusong-gu, Taejon 305-701, Korea (Rep.)
Tel : +82 42 350 3044 (office) +82 10 9095 5044 (Mobile)
Fax : +82 42 350 5044
e-mail : csbae@kaist.ac.kr/csbae@kaist.edu