TY - JOUR
T1 - Numerical simulation of combustion and soot under partially premixed combustion of low-octane gasoline
AU - An, Yanzhao
AU - Jaasim, Mohammed
AU - Vallinayagam, R.
AU - Vedharaj, S.
AU - Im, Hong G.
AU - Johansson, Bengt
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was funded by competitive research funding from King Abdullah University of Science and Technology (KAUST), and by Saudi Aramco under the FUELCOM-II program. The authors would like to thank Adrian. I. Ichim and Riyad Jambi for their technical support in conducting the engine experiments, and Convergent Science for providing licenses for the CONVERGE software.
PY - 2017/9/23
Y1 - 2017/9/23
N2 - In-cylinder combustion visualization and engine-out soot particle emissions were investigated in an optical diesel engine fueled with low octane gasoline. Single injection strategy with an early injection timing (−30 CAD aTDC) was employed to achieve partially premixed combustion (PPC) condition. A high-speed color camera was used to record the combustion images for 150 cycles. The regulated emission of carbon dioxide, carbon monoxide, nitrogen oxides and soot mass concentration were measured experimentally. Full cycle engine simulations were performed using CONVERGE™ and the simulation results matched with the experimental results. The in-cylinder soot particle evolution was performed by coupling a reduced toluene reference fuel mechanism including the PAHs formation/oxidation reactions with particulate size mimic model. The results showed that PPC presents typical stratified combustion characteristics, which is significantly different from the conventional diesel spray-driven combustion. The in-cylinder temperature and equivalence ratio overlaid with soot-NO formation regime revealed that PPC operating condition under study mostly avoided the main sooting conditions throughout the entire combustion. The evaluation of temperature distribution showed formaldehyde could be regarded as an indicator for low temperature reactions, while hydroxyl group represents the high temperature reactions. Soot evolution happened during the combustion process, hydroxyl radicals promoted the soot oxidation.
AB - In-cylinder combustion visualization and engine-out soot particle emissions were investigated in an optical diesel engine fueled with low octane gasoline. Single injection strategy with an early injection timing (−30 CAD aTDC) was employed to achieve partially premixed combustion (PPC) condition. A high-speed color camera was used to record the combustion images for 150 cycles. The regulated emission of carbon dioxide, carbon monoxide, nitrogen oxides and soot mass concentration were measured experimentally. Full cycle engine simulations were performed using CONVERGE™ and the simulation results matched with the experimental results. The in-cylinder soot particle evolution was performed by coupling a reduced toluene reference fuel mechanism including the PAHs formation/oxidation reactions with particulate size mimic model. The results showed that PPC presents typical stratified combustion characteristics, which is significantly different from the conventional diesel spray-driven combustion. The in-cylinder temperature and equivalence ratio overlaid with soot-NO formation regime revealed that PPC operating condition under study mostly avoided the main sooting conditions throughout the entire combustion. The evaluation of temperature distribution showed formaldehyde could be regarded as an indicator for low temperature reactions, while hydroxyl group represents the high temperature reactions. Soot evolution happened during the combustion process, hydroxyl radicals promoted the soot oxidation.
UR - http://hdl.handle.net/10754/626018
UR - http://www.sciencedirect.com/science/article/pii/S0016236117311729
UR - http://www.scopus.com/inward/record.url?scp=85029669486&partnerID=8YFLogxK
U2 - 10.1016/j.fuel.2017.09.064
DO - 10.1016/j.fuel.2017.09.064
M3 - Article
SN - 0016-2361
VL - 211
SP - 420
EP - 431
JO - Fuel
JF - Fuel
ER -