布设丁坝对60°弯道水流特性影响的数值模拟研究

Numerical simulation study of influence on water flow characteristics from designing a groin at a 60°bend

分别采用RNG k-ε模型和大涡模型结合气液两相流模型对60°弯道内布设丁坝前后的水流特性进行了数值模拟研究,采用VOF法捕捉自由水面,采用隐式算法SIMPLE(Semi-Implicit Method for Pressure-Linked Equations)求解速度与压力耦合方程组,有限体积法用来离散控制方程。对弯道内的水位、流速、弯道横比降的模拟值与实验值进行了比较分析,得出:大涡模型对弯道内水流流态的模拟精度较低,与之相比,采用RNG k-ε模型能更好地模拟出弯道内布设丁坝前后的流场特性。

With RNG k-εmodel and large eddy model, combining with gas-liquid two-phase flow model, numerical simulation was conducted to study the flow characteristics of a 60°bend before and after designing a groin. Free water surface was captured by VOF method. Coupled equations of velocity and pressure were solved by SIMPLE, i.e. the semi-implicit method for pressure-linked equations. The finite volume method is used to discrete governing equations. The simulation results and testing results of water level, flow velocity and bend transverse gradient were compared, based on which it is concluded that for simulation of bend flow pattern, the accuracy of large eddy model is relatively low while that of RNG k-ε model is better.