Large Eddy Simulation of Diesel Spray Combustion Based on a Multicomponent Vaporization Model

Large-eddy simulation(LES)of diesel spray and combustion was performed coupling with a multicomponent vaporization(MCV)model.For the LES,the dynamic structure approach was adopted to simulate the subgrid turbulence.A source term was derived by an approximate de-convolution method,which was added to the transport equation of sub-grid turbulent kinetic energy to characterize the interaction between moving droplets and ambient gas phase on the sub-grid scale.The multicomponent vaporization model applied a Gamma distribution to describe the distribution of numerous fuel components.The transport equations of distribution moments were derived within the current LES framework.This model was written into the multi-dimensional KIVA-4program.The non-evaporative fuel spray and evaporative spray combustions were simulated and compared with the corresponding experimental data.Improved agreement with the experimental data in the spray structures and soot distributions is observed,which shows that the model has great potential for improving the simulation performance of diesel spray combustion process.