Multi-dimensional simulation of optimization matching of intake swirl ratio and fuel injection system parameters in a DI diesel engine

Optimization matching of intake swirl ratio with fuel injection system parameters was studied by using three-dimensional CFD software, and the effect of intake swirl on fuel spray impingement was analyzed. Results show that in the case of small surface-volume ratio of the combustion chamber, the promoting effect of intake swirl on fuel-air mixing occurs mainly after the fuel spray impingement and it also influences the axial distribution of fuel vapor near combustion chamber wall surface. In order to gain ideal spatial distribution of fuel vapor, the swirl ratio should be decreased with increasing number of nozzle hole. The axial distribution of fuel vapor near combustion chamber wall surface can be improved by changing nozzle spray angle to improve engine combustion.