Investigation of Simultaneous Effects of the Fuel Spray Angle and the Pilot Injection Timing on the Engine Performance and the Pollutant Emission in a High Speed Direct Injection (HSDI) Diesel Engine

In this research, the simultaneous effects of the fuel injection angle and the pilot injection timing on the engine performance and the pollutant emission has been studied in a High Speed Direct Injection (HSDI) Diesel Engine. For this purpose, the simulated results have been firstly compared to the experimental data and a suitable agreement has been achived for simulating the in-cylinder pressure, the heat release rate and the amount of NOx and Soot emissions. Then, the effects of fuel spray angle has been studied at the various pilot injection timing in 16 different strategies. The results show, in the case that the fuel injection angle is 120 degree and the pilot injection starts at 20o CA BTDC, the amount of in-cylinder pressure has been increased, and the amount of soot emission and the Indicated Specific Fuel Consumption (ISFC) has been decreased compared to the other cases. However the increase of NOx emission shuld be considered as a negative parameter.