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冲击射流广泛应用于短距起飞垂直降落飞行器(SVTOL)等航空航天领域。本文采用大涡模拟方法对高度欠膨胀的超声速冲击射流的流场进行了数值模拟。本文数值模拟得到了高度欠膨胀冲击射流流场中的激波结构和内外剪切层中不同尺度的涡结构。数值结果观察到了马赫盘的振荡,以及在斜激波、马赫盘及大尺度涡结构的共同作用下,射流内外剪切层之间的环形激波的生成与消失的周期过程。并对流场内剪切层的涡结构的演化进行了研究,数值结果显示内剪切层的大尺度涡结构的形成与马赫盘的振荡相关,在内外剪切层的作用下形成了壁射流区内外交错的涡结构。
Impact jet is widely used in aerospace fields such as short take-off vertical landing vehicles (SVTOL). In this paper, the large eddy simulation method is used to simulate the flow field of supersonic jet impinging highly swell. In this paper, the numerical simulation results show that the shock structures in the flow field of highly under-expanded impact jet and the different scales of vortex structures in the inner and outer shear layers. The numerical results show the Mach-plate oscillation and the periodic process of the formation and disappearance of the ring-shaped shock between the shear layers inside and outside the jet under the combined action of oblique shock, Mach plate and large-scale vortex structure. The evolution of the vortex structure in the shear field in the flow field is studied. The numerical results show that the formation of the large-scale vortex structure of the inner shear layer is related to the oscillation of the Mach disk. The wall jet is formed by the shear layers inside and outside Inter-regional alternating staggered vortex structure.