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

Abstract

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 NO_x 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 NO_x. Under two situations of different wall temperature distributions, the soot in cylinder is different by 1.3% when exhaust valves are open.

Keywords

heat transfer / space non-uniformity / soot emission / in-cylinder / diesel