Effect of Combustion Process on DI Diesel Engine Combustion Noise

The sources of the combustion noise of DI (direct injection) diesel engine were investigated in this paper. The maximum combustion pressure, maximum pressure rise rate, high frequency pressure oscillation in combustion process and their effects on diesel engine combustion noise were discussed. Fuel pilot injection technology was applied, the effects of fuel pilot injection timing, fuel pilot injection quantity, were analyzed. Main factors affecting the combustion noise were analyzed specially. The results show that pilot injection strategy should consider the pilot injection quantity and the interval time between the pilot injection and main injection under different conditions to optimize the target.