恒定有压扩散流的大涡模拟  

Large Eddy Simulation of Steady Divergent Pressure Flows

作　　者：叶飞[1] 高学平[1] 张晨[1] 宋慧芳[1] 

机构地区：[1]天津大学建筑工程学院,天津300072

出　　处：《天津大学学报》2007年第4期392-398,共7页Journal of Tianjin University(Science and Technology)

基　　金：国家自然科学基金资助项目(50579048)

摘　　要：采用大涡模拟(LES)方法对恒定有压扩散流进行了数值模拟,对大尺度漩涡直接求解Navier-Stokes方程,小尺度漩涡采用标准Smagorinsky亚格子模型模拟.针对不同雷诺数下扩散段内的水流进行数值模拟,得到了各雷诺数流动时的时均速度场,分析了不同流态下扩散段内恒定有压扩散流时均流动特性.通过对不同流态下扩散段内连续瞬态流场的分析,探讨了不同雷诺数流动时扩散段内瞬态流场结构特点以及分离区内漩涡的变化规律,指出在恒定流状态下扩散段内存在流动的局部不稳态现象(主流的非周期性摆动),并对此现象进行分析.计算结果和试验结果吻合较好.The large eddy simulation （LES） method was used to simulate the steady divergent pressure flows. The large scale eddies were calculated by Navier-Stokes equation directly, while the small scale eddies were simulated by Smagorinsky subgrid-scale model. The time average velocity distribution of the flows under different Reynold numbers were simulated and the time average characteristics of the flows at different states in the divergent segment were analyzed. The characteristics of the instantaneous flow structure in the divergent segment and the evolvement of eddies in the separation region under different Reynold numbers were discussed. It is found that the local unsteady state phenomenon （unsteady swing of the main flow） presents in the divergent segment under steady state and this phenomenon is discussed. The results simulated are consistent with the experimental results.

关 键 词：恒定有压扩散流 大涡模拟 局部不稳态现象 流动分离 漩涡 

分 类 号：TV135[水利工程—水力学及河流动力学]