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 -
It was observed that each member gave presentation with confidence coming from mature experience and abundant database, which reflects the status of KCFP.
-
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.
-
Research themes and achievements -
-
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 -
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 -
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 -
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 ***** -
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.
-
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.
-
-
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.
-
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**** -
-
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
-
combustion. Turbo-charger needs validation and supplementary operation on the model.
-
Systematic parametric study was proved to be achievable through the simulation, which could make synergetic role.
-
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 *** -
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** -
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*** -
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**** -
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***** -
-
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*** -
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 -
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*** -
Presenter’s appearance is appreciated even after he got enrolled in the industry after graduation
-
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
-
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**** -
Modelling and numerical simulation were carried out and validated with Sandia data, which is fulfilling the need for spray-lead combustion analyses.
-
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*** -
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*** -
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*** -
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*** -
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 :
[email protected]/
[email protected]
