再入飞行仿真的几个力学问题

本文针对航天器再入飞行仿真的研究。就仿真中的几个力学问题，讨论了如何建立合理的物理模型和数学模型。再入飞行仿真主要涉及刚体运动的飞行轨迹计算模型，涉及激波，表面压力。摩擦阻力。粘性干扰等因素的气动力计算模型；涉及边界层厚度，转捩，传热和物面粗糙度，辐射传热等因素的气动热计算模型；涉及结构强度，动态特性，稳定性，热应力等因素的有限元计算模型；涉及硅基和碳基防热材料，防热层温度分布等因素的热化学烧蚀模型；涉及天气严重环境指数，粒子与激波层干扰，粒子运动特性等因素的粒子侵蚀模型。涉及瞬时外形变化。气动特性变化。累积质量损失等因素的总体参数计算模型；其中要特别注意把握好对绕流流场计算，转捩准则选择，结构响应跟踪，瞬时外形圆整等问题的处理。才能使再入飞行仿真顺利进行到再入落地，而且仿真结果具有很好的可信度。

Several Mechanics Problems in Computer Simulation of Reentry Flight

According to the computer virtual simulation of reentry flight of spacecraft, several mechanics problems of the simulation were discussed. It mainly includes a few of simulating models for the simula-toin of reentry flight of spacecraft. There are flight orbit calculating models relating to motion of rigid body. There are calculating models of aerodynamics relating to shock layer form, pressure distribution on surface, friction resistance, viscous interaction and etc. There are calculating models of aerodynamic heating relating to thickness of boundary layer, transition of boundary layer, heat transfer of boundary, roughness of body surface, radiating heat of body surface and etc. There are calculating models using finite element methods relating to analysis of structural strength, analysis of dynamic characteristic, analysis of structural stability, analysis of thermal stress and etc. There are calculating models of thermochemistry ablation relating to heat-proof materials with silicon-matrix, heat-proof materials with carbide-matrix, temperature distribution of heat-proof layer and etc. There are calculating models of particle erosion relating to weather environmental severity index, interaction between particle and shock, motion characteristic of particles and etc. There are calculating models of general parameter relating to change of instantaneous contour, change of aerodynamics characteristics, lose of general mass and etc. Among them, the calculating flow fields around the spacecraft, selecting criterion of transition in boundary layers, knowing structural response of the reentry body, reorganizing instantaneous configuratoin of the spacecraft must be specially grasped. Deal with these problems excellently, not only the simulatoin of reentry flight can be done well until the earth, but also the result of the simulation has a good reliability.