超音速边界层中二维扰动的演化及小激波的产生

Evolution of a 2-D Disturbance in a Supersonic Boundary Layer and the Generation of Shocklets

通过直接数值模拟的方法,对二维超音速边界层中扰动的演化进行了研究。以某一剖面作为入口,加入T-S波,研究小扰动波逐渐增长的演化过程。发现了扰动非线性演化的特征。探讨了二种判断激波存在的方法,证实了超音速边界层中当扰动达到一定的幅值时会有小激波出现。为建立可压缩流稳定性非线性理论提供一定的依据。

Through direct numerical simulation, the evolution of a 2-D disturbance in a supersonic boundary layer has been investigated.At a chosen location,a small amplitude T-S wave was fed into the boundary layer to investigate its evolution. Characteristics of non-linear evolution have been found. Two methods were applied for the detection of shocklets, and it was found that when the amplitude of the disturbance reached a certain value, shocklets would be generated, which should be taken into consideration when non-linear theory of hydrodynamic stability for compressible flows is to be established.