NND格式在航天飞机头部段N-S方程求解中的应用

APLICATIONS OF THE NND-SCHEME TO THE SOLVING OFNAVIER-STOKES EQUATIONS ON THE FORE-HEAD OFSPACE-SHUTTLE-LIKE BODY

本文采用实质上为二阶精度的无波动、无自由参数的耗散差分格式(NND格式)求解了非定常的二维和三维完全N-S方程,对类似于航天飞机头部外形的超声速粘性气体绕流流场进行了模拟。在计算中,使用了代数网格生成技术,对脱体激波采用了装配法。作为验证算例的二维圆柱绕流计算结果同文献[4]的数据进行了比较。二维凹陷外形绕流的计算结果同无粘流结果进行了对比,由于粘性流动出现了分离,二者的壁面压力是有差异的。最后,对三维外形的绕流也进行了模拟,计算结果提供了流场的细节。

A non-oscillatory and non-free-parameter dissipation difference scheme (or NND-scheme) has been used to solve the Navier-Stokes equations. The hypersonic viscous flows over two-or three-di-mensional bodies are simulated. The numerical result of a cylinder has been compared with that of reference [4]. The numerical result of a two-dimensional indented-body has been compared with the inviscid one. The comparision shows that the surface pressure distributions of the two results are different as a result of the existence of a separation region in the flow field. It can be said that it is not suitable to simu-late a flow field containing separation region with Euler equations. A numerical simulation to the fore-head of a space-shuttle-like body has also been made in this paper.