网格分辨率与射流分裂雾化模型对柴油喷雾影响的仿真研究

基于数值模拟方法，研究了网格分辨率、时间步长和不同的射流分裂雾化模型对柴油喷雾的影响。研究表明：网格的尺寸对柴油喷雾贯穿距离和SMD的影响较为显著；当径向网格为喷孔直径的3倍时，其贯穿距离的变化趋势与实验数值基本接近，能较好地预测试验结果，径向网格越密，油束的贯穿距离越大，SMD也越大；随着轴向网格尺寸的变大，贯穿距离增大，SMD减小；随着时间步长的变化，贯穿距离不呈规律性的变化趋势，仿真计算的贯穿距离不断逼近于实验值；对于不同的射流分裂雾化模型，KH—RT模型考虑了液滴的二次雾化，因此其雾化液滴最小，贯穿距离也相对较小，SMD的数值也较小。

Multi-dimensional Simulation of Effects on Grid Resolution and Spray Break-up Models of Diesel Spray

In this paper, grid resolution, time step and spray break-up models are studied by using multi-dimensional simulation software. The results show that： spray tip penetration and SMD are significantly affected by cell size. When radial grid is 3 times of nozzle hole diameter, the changing trend of spray tip penetration is close to experiment data. Spray tip penetration and SMD is increased with radial grid. Spray tip penetration is increased with axial grid. Spray tip penetration don＇ t show regular changing trend with time step and simulation results of time step is approximations to experiment data. According to different spray break-up models, spray tip penetration and SMD is relatively small by using KH-RT model.