采用修正的二维浅水模型模拟连续弯道流场

Bend-flow simulation using modified 2D shallow water depth-averaged model

计入深度平均流速与真实流流速分布的差值所引起的扩散效应,建立了正交曲线坐标系下的平面二维浅水模型.紊动应力项采用以标准k-ε模型为基础的曲率效应修正紊流模型模拟,在一定程度上计及流线弯曲水流紊动应力各向异性.采用控制体积法、交错网格和SIMPLEC算法离散求解水流方程.采用修正后的模型对连续弯道水流进行了数值模拟,并与实测资料进行了比较,结果表明该模型能够有效地模拟流线弯曲的水流水力特性.

The purpose of this paper is to present a 2D depth-averaged model for simulating and examining flow patterns in channel bends.In particular,this paper proposes a 2D shallow water depth-averaged model that takes into account the influence of the secondary flow phenomenon through the calculation of the dispersion stresses arisen from the integration of the products of the discrepancy between the mean and the true velocity distributions.The proposed model uses an orthogonal curvilinear coordinate system to efficiently and accurately simulate the flow field with irregular boundaries.The curvature correction turbulence model with effects of streamline curvature based on the standard k-ε turbulence model is used to compute turbulence stresses.As for the numerical solution procedure,the finite volume method with the staggered grid and the SIMPLEC solution method are used to numerically solve the flow governing equations.By using the modified shallow water mathematical model,the behaviors of the flows through a meandering channel have been computed;and the computational results coincide well with the measured data.