阿波罗指令舱稀薄气体动力学特征的蒙特卡罗数值模拟

本文对阿波罗指令舱稀薄气体动力学特征进行了蒙特卡罗直接模拟（ＤＳＭＣ）。采用中点数值逼近法确定模拟分子与物面碰撞点，利用网格编号将三维计算问题一维化，把流场入口处的分子补充与分子排序有效结合，利用分子横穿流场次数确定流场稳定前的时间步长计算次数。简化了计算过程，大大节约了计算机时和内存。给出了指令舱从自由分子流到过渡区不同Ｋｎｕｄｓｅｎ数、各攻角下的气动特征。模拟结果与有关理论、实验数据相比，证实

DSMC Simulation of Hypersonic Rarefied Flow past Apollo-CM

The three-dimensional hypersollic rarefied flow about Apollo command module is simulated for monatomic gas by the direct simulation Monte Carlo (DSMC) method. The method of middle point numerical approximation is applied to determine the collision point between molecule and body surface. Cell order is used in the molecular indexing so that three dimensional problem is treated as one dimensional problem. The molecular supplement of the flowfield entrance is effectively incorporated into the molecular indexing. The computing times of time step before the stability of the flowfield is determined by the times which the molecules run across the flowfield. As a consequence, not only is the computation simplified, but also are the computation time and storage largely reduced. This paper can simulate the flow from the free molecular flow to the transition regime with all kinds of Knudsen number and angle of attack. The simulation results show the consistency with relevant experiments or theoretical results.