横流中有限宽窄缝射流的旋涡结构  

Vortex structure of slot turbulent jets in cross-flow

作　　者：姜国强[1] 李炜[2] 

机构地区：[1]天津大学机械工程学院,天津300072 [2]武汉大学水利水电学院,湖北武汉430072

出　　处：《水利学报》2004年第5期52-57,63,共7页Journal of Hydraulic Engineering

基　　金：国家自然科学基金项目(59979022)

摘　　要：本文应用PIV流动显示技术详细测量了有限宽度窄缝射流从底部射入横流的流场结构。在此基础上采用湍流数学模型及相应的混合有限分析方法,得到横流中有限宽窄缝射流的时均及瞬态流场、涡量场,以此来分析流场、涡量场特性,揭示各种具有拟序结构性质的复杂涡系的产生、发展及演化过程。实验观察到射流迎、背流剪切涡层卷起形成类开尔文涡列。本文还探讨了横流绕流分离旋涡的生成机理及其转向。另外,观测到射流喷口上游的马蹄涡系以及射流逆流区下游尾迹区旋涡的层状结构形式。通过拓扑分析的方法,给出了横流中有限宽窄缝射流旋涡近区流场的拓扑性质。The PIV technique is applied to visually measure the flow field in the vicinity of the exit of slot turbulent jet with limited width discharged into cross-flow from bottom. On this basis, mathematical model for turbulent flow and hybrid finite analytic method are adopted to derive the time averaged and instantaneous flow field and vorticity field. The generation, development and evolution of the coherent vortexes are revealed. A kind of Kelvin type vortex formed by the roll up of the jet shear layer is observed in the experiment. Furthermore, the horseshoe shape vortex system occurred to the upstream of the jet exit and the layer structure of vortexes occurred to the wake of the reverse flow region downstream of the jet are also investigated. The topological characteristics graph of flow is derived by means of topological analysis method.

关 键 词：湍流 窄缝射流 横流 旋涡结构 拓扑分析 

分 类 号：O358[理学—流体力学]