缸内直喷汽油机多孔喷雾破碎模型研究

Spray Break-up Model of Multi-hole Injector on Gasoline Direct Injection Engine

为了建立缸内直喷汽油机多孔喷油器喷雾破碎模型，对FIPA模型、HuhGosman模型和KH—RT模型进行分析评估，确定了缸内汽油直喷二次破碎模型；以喷油压力为参数，基于初始破碎粒径分布公式，建立了缸内汽油直喷喷雾破碎模型；最后通过定容喷雾实验进行汽油自由喷雾实验，验证所建模型的合理性。研究结果发现：HuhGosman模型在汽油喷雾模拟过程中，模拟结果与实际喷射过程最为接近；FIPA模型在相应模拟条件下，液滴的破碎速度过快；而KH—RT模型在该喷射条件下，液滴的破碎速度过慢。通过对HuhGosman模型进行修正，模拟计算结果与实际结果相近。最后利用该模型对不同喷油压力下的自由喷雾进行模拟，计算结果与实验结果吻合较好。

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.