Numerical investigation of velocity distribution of turbulent flow through vertically double-layered vegetation

作     者：Naveed Anjum Norio Tanaka 

作者机构：Graduate School of Science and EngineeringSaitama UniversitySaitama 338-8570Japan International Institute for Resilient SocietySaitama UniversitySaitama 338-8570Japan 

出 版 物：《Water Science and Engineering》 (水科学与水工程（英文版）)

年 卷 期：2019年第12卷第4期

页      面：319-329页

核心收录：

学科分类：07[理学] 0707[理学-海洋科学] 0713[理学-生态学] 

主　　题：Vertically double-layered vegetation Single-layered rigid vegetation Numerical modeling FLUENT Velocity distribution Turbulent flow 

摘      要：The velocity structures of flow through vertically double-layered vegetation(VDLV)as well as single-layered rigid vegetation(SLV)were investigated computationally with a three-dimensional(3D)Reynolds stress turbulence model,using the computational fluid dynamics(CFD)code *** detailed velocity distribution was explored with a varying initial Froude number(Fr),with consideration of the steady subcritical flow conditions of an inland *** VDLV flows,the numerical model successfully captured the inflection point in the profiles of mean streamwise velocities in the mixing-layer region around the top of short submerged *** upward and downward movement of flow occurred at the positions located just behind the tall and short vegetation,***,higher streamwise velocities were observed in the upper vegetation layer due to high porosity,with Pr=98%(sparse vegetation,where Pr is the porosity),as compared to those in the lower vegetation layer,which had comparatively low porosity,with Pr=91%(dense vegetation).A rising trend of velocities was found as the flow passed through the vegetation region,followed by a clear sawtooth distribution,as compared to the regions just upstream and downstream of vegetation where the flow was almost *** VDLV flows,a rising trend in the flow resistance was observed with the increase in the initial Froude number,i.e.,Fr?0.67,0.70,and ***,the flow resistance in the case of SLV was relatively very *** numerical results also show the flow structures within the vicinity of short and tall vegetation,which are difficult to attain through experimental measurements.