Effect of heat transfer space non-uniformity of combustion chamber components on in-cylinder soot emission formation in diesel engine

摘要

Combustion chamber components(cylinder head,cylinder liner,piston assembly and oil film) are treated as a coupled body.Based on the three-dimensional numerical simulation of heat transfer of the coupled body,a coupled three-dimensional calculation model for the in-cylinder working process and the combustion chamber components was built with domain decomposition and boundary coupling method,in which the coupled three-dimensional simulation of in-cylinder working process and the combustion chamber components was adopted.The simulation was applied in the influence investigation of the space non-uniformity in heat transfer among combustion chamber components on the generation of in-cylinder emissions.The results show that the space non-uniformity in heat transfer among the combustion chamber components has great influence on the generation of in-cylinder NOx emissions.The heat transfer space non-uniformity of combustion chamber components has little effect on soot formation,and far less effect on soot formation than on NOx.Under two situations of different wall temperature distributions,the soot in cylinder is different by 1.3% when exhaust valves are open.