非对称喷嘴喷雾模拟网格适用性研究  

Study of Grid Dependency of Spray Simulation on an Asymmetric-nozzle

作　　者：杨小龙[1] 张泽坪 陈征[1] 徐光辉[2] 

机构地区：[1]湖南大学机械与运载工程学院,湖南长沙410082 [2]中国北方发动机研究所,天津300380

出　　处：《湖南大学学报（自然科学版）》2016年第8期8-15,共8页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(10502029);湖南省自然科学基金资助项目(10JJ3018)~~

摘　　要：离散油滴模型(DDM)和拉格朗日油滴-欧拉气体(LDEF)算法的喷雾数值模拟对网格具有很强的依赖性.对某非对称三喷孔喷嘴的喷雾过程进行了网格参数适用性研究,分析了网格依赖性的来源,探讨了网格形式以及径向、轴向、周向网格尺寸变化对喷雾的影响,与实验数据对比了喷雾形态和贯穿距离,并研究了对索特直径的影响.分析了不同网格长宽比的影响.结果表明,非对称三喷孔喷嘴的喷雾数值仿真中,极坐标类型的网格具有更好的适用性.随着网格尺寸减小,贯穿距离和索特直径基本都呈现增大的趋势,但径向尺寸对贯穿距离的影响稍大于轴向尺寸.网格尺寸和长宽比存在一个最优值使得模拟的贯穿距离与实验值拟合得最好.Spray simulation using Lagrangian-Droplet and Eulerian-Fluid （LDEF） method and the Discrete Droplet Model （DDM） has been proved to be of grid dependency. The grid effects on the spray simulation of an asymmetric three-hole nozzle were studied. First, the sources of grid-dependency were analyzed. The effects of grid types and different grid sizes of radial, azimuthal and axial directions on the spray process were investigated by comparing the spray shape and liquid penetration distance with experiment data. And the grid effect on the Sauter Mean Diameter （SMD） was studied. Finally, the aspect ratio between the radial and the axial directions of the grid was optimized. The result has shown that, for the asymmetric three-hole nozzle spray simulation, the polar mesh has better performance among the different mesh forms. With the decrease of the grid size on three directions, the spray tip penetration and SMD basically present the tendency of increase, while the radial grid size shows greater influence than the axial size. The spray tip penetration fits best with experimental data when the grid size and the aspect ratio are optimized.

关 键 词：喷雾特性 网格适用性 数值模拟 离散油滴模型 拉格朗日油滴-欧拉气体算法 

分 类 号：TK427[动力工程及工程热物理—动力机械及工程]