充气式返回舱化学非平衡仿真分析

Chemical nonequilibrium simulation analysis of inflatable reentry decelerator

采用空气五组分模型对充气式返回舱的气动特性进行了化学非平衡数值模拟研究,考察了返回舱外形变化对流场温度和压力的分布以及壁面热流密度和压强的影响,分析了流场中组分分布情况。研究结果表明,外形变化在总体上对返回舱流场特性影响较小,会使舱体壁面处的热流密度有所增加;对流场组分分布的研究发现,由于N 2比O 2更难解离,在整个流场中N的摩尔分数远低于O的摩尔分数;在目前的计算条件下,沿轴线和壁面的氮氧比与来流基本保持一致。仿真结果在总体上与实验结果符合较好,验证了仿真模型的可靠性。

The aerodynamic characteristics of the inflatable reentry decelerator were studied with chemical nonequilibrium numerical simulation using five-species air model.The effects of reentry decelerator′s shape deformation on distributions of flow temperature and pressure,heat flux and pressure along the wall were investigated,and the mole fractions of each species in the flow filed were presented.The modeling results show that the shape deformation of inflatable reentry decelerator has little influence on flow characteristic,and leads an increase of heat flux on the capsule surface.The study of species distribution shows that since N 2 is more difficult to dissociate than O 2,the mole fraction of N is much lower than the mole fraction of O in the flow filed.Under the current calculation conditions,the ration of nitrogen and oxygen along the wall and axis is almost consistent with the incoming flow.The modeling study results are in good agreement with the experiment results,which verify the reliability of the model.