Reduction of combustion-induced noise in IDI diesel engine (2nd report, low-noise combustion system)

摘要

In order to reduce noise, fuel consumption, and smoke emission of an indirect injection (IDI) diesel engine, a combustion system that restrains pre-mixed combustion and promotes diffused combustion was investigated in a four-cylinder diesel engine with a 98mm bore and 98mm stroke. Using a combustion system which consists of a new combustion chamber with a high compression ratio and a refined jet passage whose angle inside the main chamber is smaller than that inside the prechamber, the enlargement of the jet passage area, the control of fuel injection direction, and the optimization of swirl radius in the prechamber were proven to restrain pre-mixed combustion and promote diffused combustion, as well as to reduce combustion-induced noise over a wide range from no load to full load, fuel consumption, and smoke emission.