对LVDSMC方法的改进(英文)  

Improvements to the low-variance deviational simulation Monte Carlo method

作　　者：李军[1] 沈青[1] 樊菁[1] 

机构地区：[1]中国科学院力学研究所LHD实验室,北京100190

出　　处：《空气动力学学报》2010年第2期238-243,共6页Acta Aerodynamica Sinica

基　　金：创新研究群体科学基金(10621202);国家自然科学基金(90205024);国家杰出青年科学基金(10425211)

摘　　要：最近,Homolle和Hadjiconstantinu提出了新的粒子模拟方法———LVDSMC方法[1],该方法采用了减少方差的思想从而提高了低速流动问题中的计算效率。本文针对LVDSMC方法提出两点改进:第一,除了方法中原来已采用的偏差粒子,在计算近自由分子流问题时建议额外地采用一些辅助粒子,从而可以约束计算过程中原始算法在生成偏差粒子时计算误差的累积效应;第二,提出一个可选的用于计算潜在Maxwell Boltzmann分布函数中的速度参数的增量,从而使得表面的应力及热流的计算变得简单。Recently Homolle and Hadjiconstantinou presented a new particle simulation method, i. e. LVDSMC method which incorporates the variance reduction idea thus attaining significant computational efficiency for low speed flows. In the present paper two improvements of this LVDSMC method are proposed. Firstly, additional auxiliary particles different from deviational particles used in the original LVDSMC are suggested to be introduced and the numerical error caused by the accumulation of the net number of deviational particles created can be restrained through employing such auxiliary particles, which is especially crucial in treating problems in and near free molecular regime. Secondly, an alternative principle used to determine the increment of the velocity parameter in the increment of the underlying Maxwell Boltzmann distribution in LVDSMC collision process is proposed to make easier the calculation of the momentum and energy fluxes across the surface of the boundary.

关 键 词：DSMC LVDSMC 偏差粒子 辅助粒子 

分 类 号：V211.25[航空宇航科学与技术—航空宇航推进理论与工程]