电离对高超声速稀薄流飞行器气动热影响

将电离反应模型扩展到（direct simulation Monte Carlo，DSMC）方法中，研究了电离反应效应对高超声速稀薄流飞行器气动热的影响特性.针对稀薄流场中电子出现带来的实际困难，引入“捆绑法”思想处理电子在流场中的运动，并给出了电离反应模型及电离反应处理方法.在以RAM-C Ⅱ飞行器外形为例对增加了电离反应的DSMC代码进行验证的基础上，以“星尘号”探测器外形为研究对象，针对不同飞行高度下5组元混合气体模型（无电离）和11组元混合气体模型（含电离）的化学非平衡流动开展了数值模拟，细致分析和对比了电离反应效应对探测器气动热的影响规律.研究结果表明:采用的电离反应处理方案能够模拟带电离反应的高超声速化学非平衡稀薄流动.在飞行高度为60km时电离反应对探测器气动热的影响最为强烈，使探测器的驻点热流密度降低了5.12%，电离反应对探测器气动热的影响随气体稀薄程度增加而减弱. 

Ionization effects on aerodynamic heat for vehicle in hypersonic rarefied flow

Effect of ionization reaction on aerodynamic heat characteristics for vehicle in hypersonic rarefied flow was studied by using direct simulation Monte Carlo (DSMC) method in which ionization reaction model was added. For the actual difficulties added by electron in rarefied flow, a bundling method was used to deal with electron motion. The ionization reaction model and the processing method of ionization reaction were presented. Firstly, taking the example of shape of RAM-C Ⅱ vehicle, DSMC code with addition of ionization reaction was validated. Then, a numerical experiment was made to investigate the effects of ionization reaction on aerodynamic heat characteristics of the Stardust blunt body at different altitudes by use of 5 species gas model(without ionization) and 11 species gas model(with ionization) in chemical non-equilibrium flow. The results show that the treatment scheme proposed can simulate ionization reaction for hypersonic rarefied flow. At 60km altitude, ionization reaction effect on the aerodynamic heat characteristics becomes the strongest, reducing heat flux at stagnation point by 5.12%,and the effect decreases with the increase of the rarefied content of gas.