变逆压梯度湍流边界层条纹结构的流动显示  

THE VISUAL DISPLAY OF COHERENT STRUCTURE IN THE TURBULENCE WITH VARIATIONAL ADVERSE PRESSURE GRADIENTS

作　　者：李兆瑞[1] 叶剑[1] 陆利蓬[1] 

机构地区：[1]北京航空航天大学动力系,北京100083

出　　处：《工程热物理学报》2001年第5期563-565,共3页Journal of Engineering Thermophysics

基　　金：国家重点基础研究发展规划项目(No.G1999022305);航空科学基金资助项目(No.99C51075)

摘　　要：采用氢气泡技术对凸壁扩张和凹壁扩张所形成的两种常见的变压力梯度边界层进行了流动显示研究．通过在低速下对这两种通道在上游和中间相同扩张角处条纹结构的的横向对比和对同一通道不同流向位置处的条纹结构的纵向对比，以及对较高流速下下游流动的对比，得到凹壁流动最不稳定，且其活跃程度会沿流向下放大．而凸壁的结构要稳定的多，其活跃程度沿流向增加不大．通过近似估算得出这两种流动尽管差别很大，但条纹结构的展向距距均在９０个粘性长度左右。The hydrogen bubble technique is adopted for investigating the effect of varied pressure gradient on the coherent structures in the turbulent boundary layer. The coherent structures in concave wall and protruding wall, the two more common kinds of divergent passages, are studied and the follow results are obtained. In contrast with the coherent structures in the case of protruding wall, the coherent structures are more active and much more streamwise vortices and spanwise vortices are found in concave wall. Even this activity will be enhanced along with the flow in cancave wall. Although there are some obvious differences on coherent structures, the spanwise spacing of the low- speed streaks all cluster with λ+z= 100 in the both cases.

关 键 词：变逆压梯度 显示 边界层条纹结构 旋涡结构 湍流 

分 类 号：O357[理学—流体力学]