3-D numerical simulation of curved open channel confluence flow with partially non-submerged rigid vegetation  

作　　者：Zheng-rui Shi Cong-fang Ai Sheng Jin 

机构地区：[1]School of Civil and Hydraulic Engineering,Dalian University of Technology,Dalian 116024,China

出　　处：《Journal of Hydrodynamics》2021年第5期992-1006,共15页水动力学研究与进展B辑（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.51739011);the National Key Research and Development Program of China(Grant No.2016YFC0402707-03).

摘　　要：For the study of the effects of partially non-submerged rigid vegetation on the free-surface confluence flow in a curved open channel,a numerical simulation is carried out by using the Volume of Fluid model combined with the porous media model with the software OpenFOAM.The model is first validated by using available experimental measurement data with a good agreement.Then,the characteristics of the separation zone generated by the centrifugal forces and the confluence flow are analyzed.Due to the resistance created by the vegetation,the velocities in the separation zone are more chaotic and the separation zone becomes smaller and more irregular.The reduction of the separation zone area of the vegetated flow in the convex bank is more significant than that in the concave bank.The velocities in the vegetated region become much smaller and remains so in the downstream flow after the vegetation region.Meanwhile,the vegetation compresses and divides the circulations in the flow area,rebuilding a structure with smaller circulations in the main flow and unclear circulations in the vegetation region.In addition,the bed wall shear stresses are significantly smaller in the vegetation region and the separation zone compared to the non-vegetated flow.This implies that the vegetation can have the effect of protecting the river bed from erosion.

关 键 词：Curved open channel confluence flow porous media model non-submerged rigid vegetation separation zone 

分 类 号：TV13[水利工程—水力学及河流动力学]