基于HLLC格式的异重流高分辨率立面二维数学模型  

A vertical 2D high-resolution numerical model for gravity current based on HLLC scheme

作　　者：卢新华[1] 秦超 张小峰[1] LU Xinhua;QIN Chao;ZHANG Xiaofeng(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072

出　　处：《人民长江》2021年第6期123-129,共7页Yangtze River

基　　金：国家重点研发计划项目(2016YFA0600901)。

摘　　要：异重流是自然界中的常见现象,异重流运动过程中交界面附近可能存在物理量的间断。为较好地捕捉这种间断,建立了异重流高分辨率立面二维数学模型,该模型基于同位网格的Godunov型有限体积法求解σ坐标下的雷诺时均Navier-Stokes方程组。模型中水平方向界面数值通量采用HLLC近似黎曼求解器计算,湍流封闭采用非线性K-ε模型。选用3个经典的开闸式平坡和反坡异重流试验对模型性能进行了检验。结果表明:该模型能较好地模拟异重流在平整或非平整床面上的运动过程,并具有较高的模拟精度。Gravity currents are common phenomenon in nature.Discontinuities may exist near the interface during the movement of gravity currents.In order to capture this discontinuity well,we develop a vertical 2D high-resolution numerical model for gravity currents.The developed model uses the Godunov-type finite-volume method based on the isometric grid to solve the Reynolds time-mean Navier Stokes equations inσcoordinates.The horizontal inter-cell numerical flux is evaluated by the HLLC approximate Riemann solver,and the MUSCL scheme is employed for horizontal interface value reconstructions.A nonlinear k-εmodel is employed for turbulence closure.Three classic lock-exchange experiments of gravity currents propagating on flat and adverseslope beds are employed to verify the performance of the model.Results show that the developed model simulates the movement of gravity currents well on flat or uneven bed with high accuracy.

关 键 词：异重流 HLLC 反坡异重流 Σ坐标 非线性K-ε模型 

分 类 号：TV131.2[水利工程—水力学及河流动力学]