应用于DSMC方法的二维Voronoi网格技术

研究了Voronoi网格技术并将其应用于直接模拟蒙特卡洛DSMC(Direct Simulation Monte Carlo)计算.基于Dirichlet镶嵌与Voronoi图理论,Voronoi网格利用特征点表征网格单元,具有建立粒子与网格单元之间映射关系的独特算法,适合于DSMC方法的统计特点.在剔除过于靠近边界的特征点以及必要情况下边界细化的基础上,通过区分由边界节点表征的非完整Voronoi网格单元以及由计算区域内镶嵌点表征的完整Voronoi网格单元,解决了Voronoi网格的二维边界匹配问题.Voronoi网格技术支持自适应DSMC计算.映射效率对比表明,Voronoi网格的DSMC计算效率高于三角形网格,低于多级直角网格.通过MEMS微喷管流动数值模拟,验证了Voronoi网格技术在DSMC方法中的有效性. 

Two dimensional Voronoi grid technology applied in the DSMC method

The Voronoi grid technology applied in the direct simulation Monte Carlo(DSMC) method was researched.Basing on the Dirichlet tessellation and Voronoi diagram theory,the Voronoi cells were defined by thier tessellated points and the peculiar arithmetic mapping particles to cells satisfied the statistical requirements of DSMC method.By filtering out the tessellated points too closed to the boundaries,dividing the boundaries if necessary and distinguishing the incomplete Voronoi cells defined by boundary points from the complete Voronoi cells defined by inner tessellated points,the two dimensional Voronoi grid boundary conforming problem was resolved.The Voronoi grid technology supported self-adaptive DSMC calculations.Mapping efficiency contrasts showed that efficiency of Voronoi grid was higher than triangle grid and lower than multi-level rectangular grid in the DSMC method.The validity of Voronoi grid technology in the DSMC method was confirmed by the simulation results of MEMS-based micro nozzle flow.