应用于DSMC方法的直角网格技术  

Cartesian grid technology applied in DSMC method

作　　者：侯凤龙[1] 蔡国飙[1] 

机构地区：[1]北京航空航天大学宇航学院,北京100191

出　　处：《北京航空航天大学学报》2010年第6期694-699,共6页Journal of Beijing University of Aeronautics and Astronautics

摘　　要：研究了应用于直接模拟蒙特卡洛DSMC(Direct Simulation Monte Carlo)方法的直角网格技术.通过对边界三角形表面微元进行统计,建立直角网格缺陷单元与表面微元之间的映射关系,并进一步将缺陷单元区分为一级缺陷单元以及二级缺陷单元,同时结合可变时间步长技术,从根本上解决了在DSMC方法中利用直角网格技术贴体光滑地匹配复杂几何型面的问题.给出了相应的自适应网格调整方法.基于以上策略,编制了通用DSMC计算程序RGD-Tool(Rarefied Gas Dynamic Tool).利用RGD-Tool程序对典型的圆球绕流以及无限薄斜挡板绕流两个算例进行了验证计算,结果表明所讨论直角网格技术是有效的.The Cartesian grid technology applied in DSMC（direct simulation Monte Carlo） method was studied.A strategy of counting the boundary triangle surface elements in each Cartesian grid cell for establishing the mapping relationship from bug cells to surface elements was adopted.Further more,the bug cells were distinguished as level one bug cells and level two bug cells.In addition,a variable time step technology was used.With these skills,the Cartesian grid can match complex geometric surfaces smoothly in DSMC calculations.The self-adaptive method of this Cartesian grid was presented.A general DSMC procedure,rarefied gas dynamic tool（RGD-Tool） was developed.The classical DSMC simulations of flows passing around a sphere and an inclined baffle were carried out respectively by using RGD-Tool procedure.The results show that the discussed Cartesian grid technology work well.

关 键 词：直接模拟蒙特卡罗方法 直角网格 边界 映射 

分 类 号：V439.7[航空宇航科学与技术—航空宇航推进理论与工程]