空间发展混合流的大涡模拟  

Large-eddy simulation of a spatially developing mixing layer

作　　者：林国华[1] 傅德薰[2] 马延文[2] 

机构地区：[1]北京航空航天大学,飞机设计研究所,北京100083 [2]中国科学院力学研究所,非线性力学国家重点实验室(LNM),北京100080

出　　处：《空气动力学学报》2001年第3期325-330,共6页Acta Aerodynamica Sinica

摘　　要：采用大涡模拟方法数值模拟了空间发展混合流 ,通过在平均流中引入小扰动 ,研究了混合流大涡结构的产生和演化过程 ,捕捉了展向涡的卷起、配对、合并 ,以及二次流向涡的出现等大尺度的三维拟序结构。与实验及直接数值模拟的结果相比 ,吻合程度较好 ,表明本文所采用的LES方法对湍流的数值模拟是切实可行的。Large eddy simulations of three dimensional spatially developing mixing layer with mixing transition are conducted to investigate the vortex structure of a mixing layer , their evolution and the budgets of momentum thickness, Reynolds shear stress and turbulent diffusion velocity. The numerical simulation is begun from a few low-wavenumber derived from linear stability theory in addition to the mean velocity. The coherent structure, such as the spanwise vortices(rollers), the pairing of the rollers(i.e. corotation and amalgamation of neighboring rollers)and the secondary streamwise vortex structure have been observed in present simulation. The physics captured in the present LES are consistent with the experiment and the DNS, but at a significant fraction of the DNS cost.

关 键 词：拟序结构 大涡模拟 空间发展混合流 展向涡 流向涡 LES 湍流 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]