圆管中湍旋流的精细模拟与总流机械能损失  

Refined simulation of turbulent swirling pipe flow and investigation into mechanical energy loss of total flow

作　　者：高兴[1] 刘士和[1] 王之婳 

机构地区：[1]武汉大学水利水电学院,湖北武汉430072 [2]同济大学,上海200092

出　　处：《武汉大学学报（工学版）》2016年第4期487-491,共5页Engineering Journal of Wuhan University

基　　金：水利部公益性行业科技专项经费(编号:201101005)

摘　　要：湍旋流广泛存在于自然界与工程实际中,其流动特性及机械能损失的研究具有很高的理论意义与工程价值.通过开发数值旋流生成装置,采用雷诺应力模式封闭雷诺时均方程及有针对性的网格布置,实现了对圆管中湍旋流的三维精细模拟.计算成果表明:1)湍旋流的旋流数沿程呈分段指数衰减,其衰减系数有随雷诺数的增加而减小的趋势;2)湍旋流的切向时均流速沿径向的变化在旋流数较大时可近似用组合涡的速度分布来描述;3)与一般恒定均匀圆管湍流的总流机械能损失系数相比,带有旋流的圆管湍流的总流机械能损失系数要普遍大于前者,且旋流数越大,总流机械能损失系数越大.The turbulent swirling flow is common in nature and engineering practice.The investigation on the flow characteristics and mechanical energy loss of turbulent swirling flow is of great theoretical significance and engineering value.A refined three-dimensional simulation of the swirling flow in a circular tube is conducted by developing a numerical swirl generating device,using Reynolds stress model to close Reynolds equation and targeted grid layout.The calculation results show that：1）The swirl number of turbulent swirling flow which stands for the swirl intensity decreases along the pipe,which can be described by a segmented exponential formula.Besides,the decay factor decreases with the increase of Reynolds number generally.2）The radial distribution of mean tangential velocity in the swirling flow can be roughly approximated with the velocity distribution of the compound vortex when the swirl number is large.3）Compared to the steady uniform pipe flow,the mechanical energy loss coefficient of turbulent swirling flow is generally larger and even larger with the swirl number increasing.

关 键 词：湍旋流 数值模拟 机械能损失 

分 类 号：TV131.2[水利工程—水力学及河流动力学]