航空学报 > 2014, Vol. 35 Issue (8): 2174-2181   doi: 10.7527/S1000-6893.2013.0536

一种DSMC分子仿真下的权因子预定义方法

黄飞, 沈清, 程晓丽, 赵波   

  1. 中国航天空气动力技术研究院, 北京 100074
  • 收稿日期:2013-11-04 修回日期:2014-02-10 出版日期:2014-08-25 发布日期:2014-03-05
  • 通讯作者: 程晓丽,Tel.:010-68742752,E-mail:Cheng_xiaoli@sina.com E-mail:Cheng_xiaoli@sina.com
  • 作者简介:黄飞男,硕士,高级工程师。主要研究方向:DSMC方法及稀薄气体效应的数值模拟。Tel:010-68742511,E-mail:huang05013@163.com;沈清男,博士,研究员,博士生导师。主要研究方向:计算流体力学、流动稳定性及湍流流动机理。Tel:010-88534489,E-mail:qshen2@gmail.com

A New Predefined Method of Particle Weight in DSMC Molecular Simulation

HUANG Fei, SHEN Qing, CHENG Xiaoli, ZHAO Bo   

  1. China Academy of Aerospace Aerodynamics, Beijing 100074, China
  • Received:2013-11-04 Revised:2014-02-10 Online:2014-08-25 Published:2014-03-05

摘要:

为提高直接模拟蒙特卡罗(DSMC)方法的计算效率,针对模拟初始DSMC方法中权因子难以确定的问题,通过分析权因子在DSMC方法模拟中的定义及求解方法,提出了一种DSMC分子仿真下权因子的预定义求解方法,采用平板、钝锥等典型算例验证了该方法的正确性。结果表明:权因子预定义方法能够在模拟初始提前对权因子的分布特征进行预定义求解;该方法能够使得DSMC仿真时全场的仿真分子数分布更为合理,在保证计算精度的前提下减少全场的仿真分子数,节省内存,提高计算效率。

关键词: DSMC, 非结构网格, 权因子, 稀薄气体, 计算效率

Abstract:

For improving computation efficiency of the direct simulation Monte Carlo (DSMC) method and overcoming the difficulty of prior knowledge about particle weight before the starting of DSMC simulation, a new predefined solution method of the particle weight is introduced, which can be obtained by analyzing its definition and solution method in DSMC. Validity about this method is investigated by analyzing both flat plate and blunt cone flow fields. The results show that present method can solve the particle weight distribution characteristics before the starting of simulation. The number of simulated particles is distributed more uniformly in the whole flow field with this method when comparing it with the constant particle weight. The number of simulated molecules can also be reduced effectively without causing any accuracy loss. The method also can save internal storage and improve computation efficiency.

Key words: DSMC, unstructured grid, particle weight, rarefied gas, computation efficiency

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