基于数值模拟计算的返回舱再入黑障特性分析

为了研究返回舱再入黑障区等离子鞘套的特性,利用FASTRAN软件对返回舱再入黑障段进行数值模拟计算,获得了返回舱周围流场和气体电离等参数的分布特性。结果表明:返回舱再入段由于进行高超声速飞行,气体的压缩形成强的弓体激波,激波层内气体压强增大,温度升高,气体发生电离,产生NO+离子和电子等带电体,形成了包覆在返回舱周围的等离子鞘套。通过分析不同返回舱的计算数据,得出返回舱激波层后气体温度的变化与初始速度相关,压强的变化与初始速度和初始压强相关;激波层后气体离解的程度与振动温度相关,N2较O2发生离解的振动温度高;影响等离子鞘套的主要参数是平动温度和电子数密度,其大小和分布在不同返回舱的相同归一化距离下基本一致。

Analysis of Characteristics for Reentry Capsule in Blackout Based on Numerical Simulation

In order to research the characteristics in blackout of plasma sheath for the reentry capsule, this paper simulated the reentry capsule in the blackout based on FASTRAN software, the surrounding flow field and parameters of ionized gas distribution of the reentry capsule were obtained. The results showed that the compressed gas formed strong bow shock because of supersonic flight,the pressure and temperature were both increased in the shock. The gas ionized and the NO+ and electron were generated,the plasma sheath surrounding the reentry capsule was formed. By analysing the results of different reentry capsules, they were seen that after the shock layer,the change of gas temperature was related to initial velocity, the gas pressure was related to initial velocity and initial pressure;the dissociation of gas was related to vibrational temperature,the vibrational temperature for N2 dissociated was higher than O2; the major parameters of plasma sheath were the translational temperature and the electron density, the magnitude and distribution were almost the same at the same normalized distance of different reentry capsules.