有限平板绕流Monte-Carlo方法仿真

DIRECT SIMULATION MONTE CARLO METHOD FOR RAREFIED FLOW OVER A FLAT PLATE

本文采用直接仿真Monte-Carlo方法求解有限长平板绕流等问题。本方法是通过计算机跟踪仿真分子的运动来实现数值模拟的。仿真分子间的碰撞计算由统计抽样确定。碰撞模型分别选用了硬球分子模型和负幂律分子模型。仿真分子与固壁作用采用由完全扩散反射和镜面反射按比例混合组成的模型。为了检验方法的可靠性,还计算了激波结构和Rayleigh问题等一维流动,二维计算采用同步并行程序。数值结果表明直接仿真Monte-Carlo方法能够较好地模拟稀薄气体力学中的一些问题。对于二维计算,所花费的机时和所需的内存均在国内机器所允许的范围内。

In this paper, the direct simulation Monte Carlo method is employed to solve the Rayleigh problem, shock wave structure and the flowfield along a flat plate with finite length. This method is a technique with which a rarefied gas flow is simulated by the computing model of thousands of testing molecules. Models for intermolecular collisions are assumed hard-sphere model and inverse power law model. The gas-surface interaction law used in the paper is a prescribed mixture of diffused and specular reflection. The Rayleigh problem and shock wave structure are calculated usinng general algorithm programs. The flow over a plate is calculated using a synchronized parallel algorithm program. From the results, it is concluded that the Monte Carlo direct simulation technique is a practical method for treating hypersonic flow in the entire transition regime and that domestic computers are available for treating two-dimension problems.