临近空间高超声速稀薄流中梯形缝隙绕流分析

Analysis of Hypersonic Rarefied Flow around Trapezoidal Gap in Near Space

针对高超声速飞行器表面不规则缝隙的构型特征,将其简化为梯形缝隙模型;采用直接模拟蒙特卡洛(DSMC)方法对高超声速稀薄流中的缝隙绕流问题进行数值模拟;研究了不同的缝隙壁面倾角对流场结构以及壁面参数的影响,为航天器结构设计以及热防护设计提供了数值支持。结果表明:改变倾角会改变流场结构,当倾角减小时,外部流场会更深入缝隙内部,使得缝隙内流场和表面的气动参数增强,且倾角越小,影响的程度越深。同时,倾角减小也会减小缝隙内的旋涡强度,当倾角小于30°时,缝隙内的旋涡区域完全消失。

Aiming at the configuration characteristics of irregular gaps on the surface of hypersonic vehicle,it is simplified into a trapezoidal gap model.The direct simulation Monte Carlo(DSMC)method is used to simulate the flow around gaps in the hypersonic rarefied flow.The influence of different gaps wall angles on the flow field structure and wall parameters is studied,which provides numerical support for spacecraft structural design and thermal protection design.The results show that changing the wall angle will change the structure of the flow field.When the wall angle decreases,the external flow will penetrate deeper into the gap,which enhances the aerodynamic parameters of the flow field and surface in the gap,and the smaller the angle,the deeper the influence.When the angle is less than 30°,the vortex region in the gap completely disappears.