Report on the meeting of an ISAB (Internat’l Scientific Advisory Board) Member
BIANCA Maria Vaglieco-Istituto Motori-CNR
Centre of Competence Combustion Processes
September 6-7th, 2011- LUND
I have been at the Centre of Competence Combustion Processes (KCFP) on 6-7th September 2011 and attended the presentation of all the activities. It is always a great pleasure to attend at the meeting for the presence of the academia, the industry people and the students together with the members of international advisory board for the intensive discussions during the presentations and the break time.
The meeting has been very productive. KCFP has achieved outstanding results from enormous research efforts.
The progress of each project was relevant and the presentations have been enhanced compared to 2010, even if some students are changed.
The main objective of this centre is to improve in internal combustion engines the combustion processes and to reduce the formation of NOx and PM (soot) by the knowledge of the complex thermo-fluid dynamic phenomena involved, the control of processes and advanced diagnostics based on numerical and optical diagnostics.
Three main projects can be identified: partially premixed combustion for light and heavy engine, generic diesel combustion and highly dilute spark ignition gas engine.
A large part of the work has been devoted to Partially Premixed Combustion. The activity carried out in Lund Lab is a combustion process between Homogeneous Charge Compression Ignition and the classical diffusion controlled diesel combustion. This combustion process allows to moderating the charge
This center is the best for its research activities and education in Europe in the sectors of propulsion for light and heavy duty engines. Its advanced research is clearly distinguished among three competence research and development centers in Sweden related to internal combustion engines: CERC-Chalmers, CCGeX-KTH and KCFP-Lund. The center shows an outstanding consistency of activities performed with the project objectives.
Scientific results obtained have allowed the realization and the implementation of advanced scientific methods of new scientific instruments and advanced devices. The methods implemented have been refined in order to raise the level of innovation recognized in the project evaluation stage and affect the quality of science developed. In terms of the products, the dissertations, articles, papers and patents are carried out. In particular, the results of the research activities carried out are well reported in international journals and presented at international conferences.
The centre promotes excellent opportunities for interactions with Research Organizations, Universities and Industries in the USA, in Europe and in Japan. The collaborations are continuous with other research centers in the world and the presence of wide and stable network partnerships with domestic and international industry such as Scania, Volvo and Toyota and Chevron is recognized.
The KCFP leader Professor Bengt Johansson has long-term objective and a good capability in the organization. He is able to provide motivation to his co-workers, junior researchers and technicians, who collaborate with strong commitment Towards High Efficiency of engine in terms of high level of research and technology development. The research topics of center must be considered an outstanding objective to short and long term both for engine manufactures and small and large enterprises of engine components and material producers.
Detailed comments on each project, based on the presentation in KCFP 2011 Meeting on 6-7th, September 2011
All presentations were comprehensible and reported well the progresses, contribution and ideas of each research activity.
1. KCFP introduction
Director, Bengt Johansson
The history and background of KCFP that has carried out to PPC and THE concept was described. The leadership of this centre in the field of innovative combustion processes is widely reported.
The research activity that carried out from HCCI to PPC in the two decades (1990-2010) is point out with detailed data. The roadmaps of engine manufactures for LD and HD engines.
The projects are well focused by gasoline PPC such as THE Combustion, THE Cycle, THE Gas Exchange et etc. The concurrent systems (Diesel and SI) and theme of PPC can be the good combination for fuel efficiency improvement.
The three main areas and the six subprojects (Diesel: Gendies, SI:Gas engine, PPC: Optical diagnostics, Fuel effects, Model and Control) allow to executing THE concept, thanks to the potential Lund personnel (professors, researchers and PhD students) and cooperation with industry staff.
THE concept of phase 6 is the core business of KCFP leadership. It is well organized by Prof. B. Johansson his capability is worldwide recognized by industry organization and specialists of relevant laboratories such as Sandia and university of Wisconsin (USA).
The activities carried out and the results reached in Phase 6 (2010-2013) allow believing that THE theme is reasonable and promising. In order to reach this objective is necessary a continuous cooperation with engine industries for constant and innovative hardware. This could allow to reaching more of 57% indicated efficiency at maximum for gasoline engine both single and multi-cylinder engine of Scania and Volvo. This result is good agreement with engine producer roadmaps.
2. PPC-Light Duty
2.1 Gasoline PPC Combustion Chamber Comparison at Low Load Operating Conditions with Negative Valve Overlap
Patrick Borgqvist
· The work of this PHD student is wide and interesting and of high level.
· He uses the fully variable actuators (VVA) that allows a wide investigation on gasoline PPC at negative valve overlap (NVO) timing with unique the piston top benchmarking Toyota made by Lund research group.
· The aim is to improve the stability at low load and to operate at very low load with very high gasoline octane number.
· The interest of low load condition of 800 rpm-2 bar IMEP is good start point for the study on cold start and idle condition for LD engine. The extension to the low load side in terms of its stable operation for various fuels must be considered. The choice of injection pressure in order to reach lowest HC and COVimep and intake/exhaust conditions should be identified for best database accumulation, which will serve for final optimization and mapping strategy in PPC-LD.
2.2 Effects of glow plug and NVO-pilot with high octane gasoline at low load
Hjalmar Arvidson:
· The PPC was tested to run at low MEP condition with high octane fuels. The effects of glow plug (with/without) and of NVO-main/pilot injection ratio is a relevant research. The glow lug must consider as a good improvement because it increases stability at low load, the effects have not a linear trend. In particular, minor effect is observed at 3.5 bar on meanwhile it is bigger at 2.5 bar. Moreover, shorter ignition delay results in higher NOx, soot, but lower HC and CO.
· The engine condition of 4.5 bar BMEP was previously reported (sept. 2010). A comparison could be interesting.
· The crevice trap of charge and the in-cylinder wall wetting to investigate the combustion process of gasoline PPC at NVO condition must be evaluated. The use of optical diagnostics can be considered.
· The results reported on pressure measurements give some problems. Next presentation must report some comments.
· The choice of injection strategy at different IMEP (in glow plug experiment) is not clarify.
2.3 Effects of NVO using different high octane fuels at low load
Olivian Marku:
· The data reported give interesting results on soot reduction, even if HC/CO remains high. This will require the use of an efficient after-treatment device. The market after-treatment devices could not work well in time.
2.4 PPC LD future plans
Patrick Borgqvist:
· The comparison between real (single cylinder) and optical engine is considered in order to evaluate better PPC combustion processes.
· Several engine parameters investigation to complete the database of gasoline PPC and correlate with numerical code data.
3. Partially Premixed Combustion, PPC in Heavy duty engine, PPC-HD
3.1 Update and preparations for the next campaign
Mengqin Shen
· No relevant results: the student has started recently.
· The approach and planning could allow good results for the experiment.
· It could better to be connected with the earlier activity presented september 2010.
3.2 Diesel-PPC engine: Predictive full cycle modeling with reduced and detailed chemistry
Martin Tunér
There is a transition of student.
· Set-up of a predictive model was presented.
· 1-D SRM PPC model was based on the GT-Power and DARS-ESM combination.
· It is relevant to predict PPC-HD diesel experiment. The problem remains the choice of fuel between n-heptane and n-decane, because each fuel contributes to reach not completely the best results. This occurs for everyone simulates the diesel fuel.
· Good agreements on mass flows, HR, efficiencies and gaseous emissions. The soot needs more work yet.
4. PPC–Optical Diagnostics
4.1 Spray penetration: the first application of the new high-speed imaging system
Rikard Wellander
· The use of kHz laser imaging technique applied to Volvo D5 with quartz liner with metal piston allows a better investigation of injection strategies for different fuels.
· The results are a good start.
· This technique can allow more results on engine cycle dispersion.
4.2 Introduction of optical engines
Director: Bengt Johansson
· The KCFP optical engines are shown, the different capability allows to being the distinctive center to cover the most range of experiments, from innovative (optical) to conventional measurements.
5. Partially Premixed Combustion modeling, PPC-model
5.1 CFD modeling of PPC using Large Eddy Simulation (LES)
Rickard Solsjö, Mehdi Jangi, Xue-Song Bai
· Good achievements are reported. The LPT/LES modeling allows good results in fuel injection with CCM in ignition chemistry and enabled faster calculation at faster speed (1/4).
· The comparison between in-house code and Open FOAM is process very valuable information for simulation people all over the world.
· It will be assured next year on its wide applicability for complex conditions
5.2 Development of chemistry coordinate mapping (CCM) approach for combustion modeling with finite rate chemistry
Mehdi Jangi, Xue-Song Bai
· DNS-CCM and full DNS calculation reach the same results at faster speed (1/4).
· RANS-CCM also showed unbelievable achievement.
· This is a revelant activity and it is strategic for the center. More efforts are necessary in order to have more results for next year.
6. Partially Premixed Combustion, PPC – Fuel Aspects, PPC-Fuel
6.1 Low load performance of gasoline fuels in comparison with diesel
Hadeel Solaka
· Multi-parameter study on gasoline vs. diesel PPC in Volvo D5 was made. .
· Fuels effect on combustion process and pollutants emissions were investigated widely
· Many data are necessary to realize the efficient database on fuel requirements in PPC engine operating conditions. The future work is promising. A relation with results reported in sept.2010 must be made.
7. Partially Premixed Combustion, PPC – Combustion Control, PPC-Control
7.1 Automatic calibration of diesel PPC model
Anders Widd
· Models are uncomplicated and the simplification seems work well. More tests are necessary for next presentation.
· It is useful for controlling combustion phasing and suppressing effects of changes in load, engine speed, etc.
· It can allow a simple and perfect engine control because it is very fast computation time on a standard desktop PC.
7.2 Collaboration with ACCM, Linz, in the field of combustion control
Per Tunestål
· The description of this collaboration with ACCM concerns on diesel PPC of KCFP, which can allow useful results. In particular, the knowledge gained from ACCM diesel PPC activities will be valuable also to the gasoline activities.
8. Gas engine project
8.1 Prechamber spark plug (PCSP)-Initial tests
Ashish Shah
· PC SP test are carried out in a Volvo MPI 6-cyl. engine. It contributes to the advance of combustion and the increase the lean operation limit.
· More diagnostics could improve to understand the contradictory results about high NOx at low combustion efficiency, higher HC with lower fuel consumption.
· These results can be useful for other fuels too.
Martin Turner -Swedish Energy Agency Report
· Studies on small scale gasification for gas engine CHP biofuels are reported. This can be considered a future interesting topic.
9. Generic Diesel Engine project, GenDies
9-1. Is the quasi-steady jet a useful picture for understanding soot emissions from diesel engines?
Öivind Andersson
· A detailed analysis is carried out with an accurate experiment during premixed- quasi-steady - and late - phases.
· Combination of measurements on equivalence ratio and soot provides valuable information on the mechanism at different mixing and combustion phases.
· Next results could contribute to better knowledge on soot formation process.
9.2 Influence of jet-jet interactions on the lift-off length in an optical diesel engine
Clement Chartier
· An accurate activity is reported on the relationship between lift-off length and inter-jet angle, injection pressure and gas temperatures. It is broadly studied by soot and OH measurements.
· A better interpretation of measurements could complete and will give more physical insights.
9.3 Investigating the mixing in wall-jets using Structured Laser Illumination Planar Imaging (SLIPI) Investigation of Air Entrainment in Wall-Jets using SLIPI (Ongoing activity)
Clement Chartier and Elias Kristensson
· Preliminary results on SLIPI LIF that allow handy in-cylinder measurements
· A refined specification on temporal and spatial resolutions is necessary
10.Towards Diesel Engine with 60% Fuel Efficiency, D60
10.1 D60 status (No assessment)
Martin Tunér
· This project is an attraction of Lund efforts in the future engine development even if it is not a KCFP dedicated project. It is not funded by Swedish Energy Agency.
· Its results and those of the other KCFP projects are beneficial for both sides.
10.2 Heat transfer modeling
Helgi Fridriksson
· Preliminary results are reported for new heat transfer model.
10.3 Wall temperature measurements
Martin Algotsson and Christoph Knappe
· Difficult experiment, good results a new advanced diagnostic.
· Simple model on heat transfer in optical engine was also adopted together.
10.4. Measurements of hydrogen peroxide (HCO) concentrations in an HCCI engine using photofragmentation laser-induced fluorescence
Malin Johnsson and Bo Li
· Preliminary correlation between 2D HCO measurements obtained by optical measurements using PRF50 fuel and modeling results.
10.5. PPC-HD full cycle kinetics modeling
Martin Tunér
· Start up of new activity for full cycle kinetics modeling reported in 3.2.
Other comments and conclusions
The organization and harmony of KCFP is valuable in terms of research activities, continuous collaborations between the subjects and international research centers and industries. Moreover, further developments are expected in coming years for control, model and advanced diagnostics.