二维喷管的初始流动

基于可压缩Navier-Stokes方程,采用大涡模拟方法与高精度混合WENO/TCD格式,对Ma=1.4的超声速平面射流初始流场进行了数值研究.数值结果清晰地描述了超声速平面射流初始流场的结构特征,包括主涡环与激波结构以及它们演变过程.因主涡环内存在涡导激波对,激波与涡相互作用加速射流剪切层失稳,使剪切层首次卷起形成小涡的位置出现在涡导激波对后,此与亚声速射流情况不同.小涡串卷起成后,相继与涡导激波对相互作用,使激波出现明显的变形并加速主涡环失稳. 

Initial flow of 2-D planer nozzle

Based on the compressible Navier-Stokes equation, the initial flow structures of a supersonic planar jet at Ma=1.4 were investigated numerically with use of large eddy simulation (LES) and combination of the high-order hybrid WENO/TCD schemes. The numerical results illustrate clearly the initial flow characteristics of a supersonic planar jet, such as the generation and evolution of the main vortex ring and shock structures. Since the vortex-induced shock pair appears in the main vortex ring, the interaction of shock with vortex can accelerate the instability of jet shear layer, making the first roll up location differ from the subsonic case of just downstream the vortex-induced shock pair. After the vortexlets formation, the subsequent interactions with the vortex-induced shock pair would lead to a significant shape deformation of shock and accelerate the instability of main vortex ring.