复式断面明渠紊流三维直接数值模拟  

Three-dimensional Direct Numerical Simulation of Compound Open Channel Flows

作　　者：陈勇[1] 及春宁[1] 许栋[1] Chen Yong Ji Chunning Xu Dong(State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300072, Chin)

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300072

出　　处：《港工技术》2017年第2期1-5,共5页Port Engineering Technology

基　　金：国家自然科学基金项目(51579175)

摘　　要：应用直接数值模拟,研究了中等雷诺数条件下复式断面明渠的二次流和紊流特性,并与矩形断面明渠紊流的结果进行了对比。研究发现:与矩形断面明渠紊流相比,复式断面明渠紊流的顺流向最大流速较大,单位面积流量增大了10%;在漫滩和深槽结合处,二次流强度较大;漫滩底面附近出现高速流体,导致漫滩处的壁面剪切应力增大;顺流向紊动速度和竖向紊动速度的相关性较低,漫滩底面紊流拟序结构较弱,没有形成尺度较大的准顺流向"发卡"涡。The turbulence characteristics and secondary flows in a compound open channel were investigated by using the direct numerical simulation. For comparison, the simulation of turbulent flow in a corresponding rectangular open channel was carried out. It was found that, compare to those of rectangular open channel flow, the maximum stream wise velocity, averaged over time and stream wise direction, was larger and the stream wise flux per unit area was 10 percent larger. At the junction of flood plain and trench, a strong s-condary flow could be observed. The high-momentum flow, carried down by the secondary flow, near the bottom of flood plain led to the large wall shear stress. It was also found that the correlation between the fluctuating velocities in the stream wise and vertical directions was low and thus the turbulent coherent structures were weak due to the absent of large-scale quasi-stream wise hairpin vortices

关 键 词：复式断面明渠 直接数值模拟 二次流 

分 类 号：TV142.1[水利工程—水力学及河流动力学]