针对高超声速飞行器气动热环境的化学非平衡效应进行数值模拟.首先以二维圆柱钝体为模型,采用三种气体模型比较和分析化学非平衡效应对气动特性和气动加热特性的影响;接着以三维球头钝体为模型,进一步分析化学非平衡效应及壁面催化特性对气动加热特性的影响.分析表明,化学非平衡效应对压力分布的影响不大;但它能显著缩短激波脱体距离,更重要的是,能大幅降低波后温度,对飞行器气动热环境产生深远影响.另外,壁面催化特性对传热也有较大的影响,对壁面材料催化进程的有效控制可以大幅降低壁面传热.
Chemical nonequilibrium effect on aeroheating environment of hypersonic vehicles is numerically investigated. First, three gas models are considered for comparing chemical nonequilibrium effect on aerodynamic and aeroheating characteristics over a 2D cylinder-blunt body. Then, a 3D sphere-blunt body is taken to further investigate chemical nonequilibrium effect, especially wall catalysis effect on aeroheating environment. It indicates that chemical nonequilibrium effect does not affect pressure significantly, but reduces shock-standoff distance remarkably and, more importantly, post-shock temperature, and hence affects aeroheating environment significantly. Moreover, wall catalysis effect affects aeroheating environment significantly, and thus effective control of this process reduces wall heat transfer considerably. It is concluded that understanding and accurate prediction of chemical nonequilibrium effect are of decisive importance for the design of thermal protection systems (TPS) of hypersonic vehicles.