超声速平面剪切层多模态混合扰动数值分析

Numerical analysis of multi-mode mixed disturbance wave in a supersonic plane shear layer

对Mac=1.2二维空间发展超声速平面自由剪切层进行扰动模态及流动结构数值分析.使用线性稳定理论和扰动直接数值模拟方法对超声速剪切层中不同流向站位的流动剖面进行扰动参数分析和局部扰动直接数值模拟,获得了剪切层不同站位处的扰动特性.通过特定单频扰动下的直接数值模拟,在剪切层的不同区域内,无相差地促发了慢模态、混合模态和快模态等多种声涡模态,得到了特定单频扰动促发的多模态无相差不稳定波.

Disturbance modes and flow structures were numerically analyzed for a two-dimensional spatial evolving supersonic plane free shear layer at Mac = 1.2.The disturbance modes and the disturbances parameters of streamwise stations were analyzed with linear stability theory（LST） method and disturbance form direct numerical simulation（DNS） method.The disturbance wave evolving of specially designed disturbance frequency was simulated with disturbance form DNS method.It is found that the multi-mode disturbance without phase difference is produced by the specially designed disturbance frequency in the shear layer.