摘要
传统的直接模拟Monte Carlo(DSMC)程序以直角网格为基础,在计算复杂的流动边界时不可避免地会带来一定误差。非结构网格虽然能够贴体地适应任何复杂流动边界,但因其拓扑结构的无序性、算法复杂、效率低等缺点而较少使用。该文提出一种基于Delaunay三角形网格的粒子轨迹追踪算法。该算法用背景网格将计算域分成若干矩形区域,通过首先确定矩形区域再搜索三角形网格的方法实现粒子轨迹的追踪与定位。以该算法为核心编制了C语言版本的2维DSMC计算程序。通过与经典文献算例对比,验证了该算法的有效性。利用该DSMC程序研究了真空腔室内喷淋头(showerhead)微孔孔径变化对流场分布均匀性的影响。中性参考气体为氩气,固定入口压力200Pa、温度300K。结果表明:增加微孔孔径有利于提高径向速度和温度分布的均匀性,而减小微孔孔径有利于提高径向压力分布的均匀性。
Traditional direct simulation Monte Carlo （DSMC） models using rectangular elements inevitably have errors when dealing with complex computational domain boundaries. Unstructured grids are able to adapt to any complex geometric shape but are rarely applied because of the highly disordered topological structure, complex calculations and low execution efficiency. This paper describes a particle trajectory tracking algorithm based on an unstructured Delaunay triangle mesh. The computational domain is divided into various rectangular regions with only a small number of triangular elements with the particle trajectory tracking achieved by first searching the rectangular regions and then the triangular elements.The algorithm is used in a two-dimensional DSMC program with the results comparing well with results in the literature. The DSMC program is then used to predict the flow field in a showerhead aperture with argon as the neutral reference gas with an inlet pressure of 200 Pa and an inlet temperature of 300 K. The results show that the radial velocity and temperature distributions are less affected by the showerhead aperture than by the radial pressure distribution. Increasing the showerhead aperture improves the radial velocity and temperature distribution uniformity, while decreasing the showerhead aperture improves the radial pressure distribution uniformity.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2015年第10期1079-1086,1097,共9页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金项目(51005132)
国家科技重大专项资助项目(2011ZX02403-004)
关键词
真空腔室
喷淋头
微孔
DSMC
数值模拟
非结构网格
vacuum chamber
showerhead
millipore
direct simulation Monte Carlo （DSMC）
numerical simulation
unstructured grid
