Numerical Simulation and Experimental Study of Mixture Formation and Combustion Process in a DI Diesel Engine

In the present study, an improved multi-dimensional CFD code has been used to simulate the mixture formation and combustion process of a DI diesel engine. WAVE breakup model constants C₀ and C₁ are modified according to a linear expression, which is a function relation to the gas pressure in-cylinder. Reasonable agreements of the measured and simulated data of in-cylinder pressure, mean temperature, NOx and soot emissions were achieved for different engine operation conditions. At the same time, the effects of different spray angles on the diesel engine mixture formation and combustion have been further simulated based on the improved multi-dimensional fuel spray and combustion models. The influence of different testing conditions mentioned above on the PM and gaseous pollutant was also discussed in this paper. Predicted trends of soot and NOx formation are also presented together with the corresponding measured data. It has demonstrated that the developed multi-dimensional engine fuel spray, combustion and emission formation model has provided a good insight for a new design of different engine parameters and in-cylinder engine events.