再入等离子体流动及其电磁波传输效应研究

摘要

基于求解N-S方程的数值方法和求解波动方程的WKB方法,建立了高超声速再入等离子体流场及其对电磁波传输影响的计算分析手段.通过比较分析飞行条件下再入体周围等离子体分布及其对通信的影响,初步验证了计算分析方法的可行性.在对再入等离子体流场数值模拟的基础上,计算了不同频率电磁波在等离子体介质中的传输特性,分析了再入体壁面催化条件及等离子体碰撞频率等因素对不同频率电磁波传输特性的影响.研究表明:再入高度越高,壁面催化对等离子体分布及其电磁波传输的影响越大;当电磁波频率低于特征碰撞频率时,碰撞频率可对电磁波传输特性产生显著影响.%Based on the numerical method for solving Navier-Stokes equations and the Wentzel-Kramers-Brillouin (WKB) method for solving wave equations,the computational codes for simulating the reentry plasma flow and its effects on the electromagnetic wave transmission are developed.The methods are validated preliminarily by comparing the computational results with the experimental ones for flight conditions.On the basis of the numerical simulation of the plasma flow field,the transmission characteristics of the electromagnetic wave in plasma flow are computed,and the effects of the surface catalysis and the plasma collision frequencies on the electromagnetic wave transmission are analyzed.The research shows that the effects of the surface catalysis are more important with reentry height increasing,and the collision frequencies can influence severely the transmission of the electromagnetic wave when its frequencies are lower than the characteristic collision frequencies of plasma.