摘要
绕植物群流动通常被简化为绕柱群流动问题,而多孔介质模型可用于概化植被对水流的影响。该文基于自主开发的自由表面水流计算模型HydroFlow■,建立了多孔介质水流模型。该模型采用坐标变换捕捉自由表面,湍流模型选用SST k-ω两方程模型。开展了不同植被密度(Φ=0.03,0.1,0.22,0.38)及植被相对水深高度(h_(v)/H=0.25,0.5,0.75,1)条件下的数值模拟研究。通过对比已有的物理模型实验测量数据,验证了数值模型的模拟精度和可靠性。基于设计工况的计算结果分析,提炼得到综合考虑了植被相对水深高度和植被密度影响的特征变量(h_(v)/H)/C_(D)aD。研究结果表明,植物群落后的溢出流速Ue和尾流区剪切层发展长度L1均与该特征量满足对数增长规律。分析尾流场的流动特征,在植被尾流流动的自由恢复阶段,横断面内流速分布均具有相似性,满足平面尾流方程,且该相似性与植被密度和植被淹没深度相关性较弱。
The vegetated flow is often simplified as the flow around a cirlular patch of cylinders,and the porous media model can be used to characterize the influence of vegetation on the flow.In the paper,the simulations with different vegetation density(=0.03,0.1,0.22,0.38)and vegetation height relative water depth(h_(v)/H=0.25,0.5,0.75,1)are performed using an in-house hydrodynamic software coupled with porous media model called HydroFlow■.In the CFD model,coordinate transformation is used to capture the free surface and the SST k-ω turbulence model is adopted for turbulence.The accuracy and reliability of the numerical model are verified by comparing with experimental data.Based on the data analysis,a characteristic variable(h_(v)/H)/C_(D)aD that comprehensively considered the effects of vegetation density and vegetation height relative water depth is proposed.Both the bleeding velocity Ue and the development length L1 of the shear layer in the wake are found to satisfy the logarithmic growth law with it.In addition,the mean velocity profiles in lateral direction are similar in the free recovery stage of the vegetation wake,which satisfied the plane wake equation and the similarity has weak relationship on the vegetation density and vegetation submergence.
作者
江雅赛
张景新
JIANG Ya-sai;ZHANG Jing-xin(School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;MOE Key Laboratory of Hydrodynamics,Shanghai Jiao Tong University,Shanghai 200240,China)
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2021年第3期429-438,共10页
Chinese Journal of Hydrodynamics
关键词
多孔介质模型
植被水流
淹没度
尾流
剪切层
porous medium model
vegetated flow
submergence
wake
shear layer
作者简介
江雅赛(1996-),女,浙江丽水人,硕士研究生;张景新,E-mail:zhangjingxin@sjtu.edu.cn。
