气膜孔形状对高超声速飞行器对撞流气膜冷却效果的影响

文章通过仿真分析手段研究飞行高度50 km、飞行马赫数15的飞行条件下，不同孔型对对撞流的影响，得到不同孔型对气膜冷却效果的影响规律。采用计算流体动力学（CFD）方法，对在入口压力0.5 MPa、质量流量22.5 g/s的稳定短模态（SPM）工作模态下，气膜孔为圆柱直孔、收缩孔、连续扩张孔、分段扩张孔等工况开展对比研究，结果显示，扩张孔气膜冷却的壁面热流最大，圆柱孔的次之，收缩孔的最小。这表明，通过改变对撞流气膜孔的形状可以改变气流流动特性，进而产生不同的气膜冷却效果，在SPM工作模态下收缩孔的气膜冷却效果最好。

Influence of the shape of the film hole on the film cooling under impinging stream for hypersonic vehicles

This paper studies the influence of different hole shapes on the film cooling to determine the dependency of the film cooling on the shape of the film hole in the impinging stream under the condition of 15 km in height and 15Ma in velocity. The CFD method is used to simulate four kinds of cooling holes, namely, the cylindrical hole, the shrinkage hole, the continuous expansion hole, and the piecewise expansion hole under the working state of the stable short penetration model (SPM), where the film cooling hole inlet conditions are set to be 0.5 MPa for the inlet pressure and 22.5 g/s for the mass flow. It is shown that the heat flux on the vehicle wall with the expansion hole is the maximum among the three cases; the value is smaller for the case of the cylindrical hole, and the lowest value is found for the shrinkage hole case. So that the shape of the hole can change the flow characteristics of impinging streams, manifested as different film cooling degrees. The best effect is seen for the shrinkage hole under SPM working mode.