Abstract:In order to establish break-up model of multi-hole injection on gasoline direct injection engine, an analysis and evaluation on FIPA model, Huh Gosman model and KH-RT model has been done. The second break-up model was built for gasoline direct injection in cylinder, and the primary break-up particle size distribution formula was also built based on injection pressure. So the break-up model of gasoline direct injection in cylinder was established. At last, by carrying out capacity spray experiments, gasoline free spray experiments were done to verify the reasonability of the established model. It was found that Huh Gosman model has the best simulation results compared with other models. The droplets break relatively too fast with FIPA model and too slowly with KH-RT under the same simulation condition. After modifying Huh Gosman model, the simulation results showed close to the practical ones. At last, free sprays under different injection pressures were simulated with the above established model. Calculation results match well with the experimental results.