小攻角高超声速钝锥边界层内扰动演化的数值模拟

Numerical simulation of disturbance evolution in the boundary layer of a hypersonic blunt cone at low incidence

首先从有限差分格式出发,给出了基本无振荡的高阶激波捕捉格式,然后,采用数值模拟方法对马赫数为6的2°攻角高超声速钝锥边界层的稳定性进行了研究。计算发现,由于攻角的存在,钝锥的稳定性特征与零攻角时有本质的差别,比如背风面的扰动比迎风面增长更快,但扰动增长最慢的地方并不是迎风面,而是侧面的某个位置;又比如背风面主要是长波起作用,迎风面和侧面主要是短波起作用;斜模式不稳定在整个钝锥边界层中起最主要作用。

A nonoscillatory high-order shock-capturing finite difference scheme is employed as a numerical tool to study the instabilities of hypersonic boundary layers. The boundary instabilities of a Mach 6 blunt cone at 2 degree angle of attack （AOA） are studied by numerical simulations. The results show that the stability characters are quite different from the cases without AOA. The leeward boundary is more unstable than the windward boundary. The most stable position is not in the windward, but in the sideward. The unstable waves in the leeward are mainly long waves, while the unstable waves in the windward and sideward are shorter ones. The main instability mechanisms are oblique models.