立楔诱导的高超声速流动分离数值分析

摘要

高超声速飞行器进气道等关键部件引起的激波与边界层相互作用将导致流动分离,从而改变当地压力分布与局部受热情况,影响飞行稳定性与飞行安全,因此需要对高超声速流动的分离现象进行细致研究.采用高精度5阶特征型WENO格式与3阶TVD型Runge-Kutta方法,求解三维Navier- Stokes方程,对立楔诱导的高超声速激波与边界层相互作用引起的分离流动流场结构进行了细致的数值模拟与分析.结果表明,5阶特征型WENO格式分辨率远高于类TVD格式；Ma =6时得到清晰的激波结构、分离涡结构及其演化过程和壁面极限流线的拓扑结构,证明了WENO格式应用于高超声速分离流动的可行性与高分辨率；对不同来流Mach数的对比证明Mach数的增大抑制流动分离,导致分离涡减小.%Separated flow caused by shock wave/boundary layer interaction will affect the local pressure distribution and heating environment which could compromise the stability and safety of the vehicles,so it' s necessary and important to investigate the detail of separated flow structures lo help finding efficient control methods. In this paper, fifth- order characteristic- wise WENO scheme and third- order TVD Runge- Kutta method were applied to solve the three-dimensional Navier-Stokes equations,to understand the flow pattern caused by shock wave/boundary layer interaction induced by a fin. The results showed that fifth- order characteristic- wise WENO scheme was more accurate than TVD schemes and applicable to hypersonic separated flow simulation; the structures of the separated and attached flows were obtained by studying the streamlines on the solid surfaces,analysis of ihe topological pattern of streamlines on the cross- section planes gave the evolution process of the separated vortex; flow separation could be reduced when the Mach number of inflow increased.