明渠交汇口三维水力特性大涡模拟研究  

Study of three-dimensional characteristics of flow at open-channel junctions by large eddy simulation

作　　者：魏文礼[1] 张泽伟[1] 邵世鹏[1] 刘玉玲[1] 戎贵文[2] 

机构地区：[1]西安理工大学水利水电学院,陕西西安710048 [2]安徽理工大学地球与环境学院,安徽淮南232001

出　　处：《武汉大学学报（工学版）》2016年第2期173-179,186,共8页Engineering Journal of Wuhan University

基　　金：国家自然科学基金资助项目(编号:51578452;51178391);陕西省科学研究计划项目(编号:2014K15-03-05);陕西省西北旱区生态水利工程重点实验室开放基金项目(编号:106-221223);中央财政支持地方高校发展专项资金特色重点学科项目(编号:106-00X101)

摘　　要：为了解决明渠水流交汇口河道冲刷、泥沙沉淤、污染物滞留等问题,必须探明其水力特性的分布规律.采用气液两相流混合模型,对不同汇流比下90°明渠交汇口三维水力特性进行数值模拟研究.分别选取大涡模拟模型(LES)和RNGk-ε模型封闭两相流时均方程,速度与压力耦合方程组求解时使用半隐式SIMPLE(Semi-Implicit Method for Pressure-Linked Equations)算法,模拟自由水面采用VOF(Volume of Fluid)法.将汇流比为0.25时两种模型计算的纵向截面水面线与实验结果相比较,得出大涡模型结合VOF法能更好地捕捉交汇口水面的波动情况;将大涡模型计算的不同垂直线上的速度分布与实验结果相比较,两者吻合良好.通过比较两种模型计算的特征横断面上的流线图,得出大涡模型能更好地捕获水流瞬时流动特性,动态再现二次流动结构,且大涡模型能够更好地模拟交汇口附近水力特性分布规律.In order to solve the river erosion,sediment deposition,pollutant accumulation and other problems at open channel junctions,distribution of 3Dhydraulic characteristics must be priorly studied.The gas-liquid two-phase mixture model is used to numerically compute the hydraulic characteristics of 90°open-channel junction flows at different discharge ratios.The large eddy simulation（LES）model and the RNGk-ε model are used to close the two-phase time-averaged equations;the SIMPLE（semi-implicit method for pressure-linked equations）algorithm is used to solve velocity and pressure coupling equations;and simulation of free surface is done by the VOF（volume of fluid）method.Comparisons of computed water surface lines with the experimental data show that the large eddy model combined with the VOF method can better capture the water surface at open channel junctions.Comparisons of the computed velocity distribution along different vertical lines with the experimental data show that they are in good agreement.Comparisons of the flow patterns on characteristic cross-sections computed by the two models show that the large eddy model can better capture the flow characteristics of flow transient,and can dynamically represent secondary flow structure.The research results also show that the large eddy model can better simulate the hydraulic characteristics at open channel junctions.

关 键 词：明渠交汇口 数值模拟 大涡模拟模型 RNGk-ε模型 水力特性 

分 类 号：TV131.4[水利工程—水力学及河流动力学]