弯肘型尾水管非定常涡旋流动数值模拟

Numerical simulation of the unsteady swirl flow in an elbow draft tube

本文采用有限体积法求解用代数雷诺应力模型封闭的雷诺平均N S方程组 ,对湖北清江隔河岩水电站 1号发电机组的尾水管 ,在部分负荷工况运行时的非定常涡旋流动进行了数值分析。结果表明 ,在水轮机部分负荷运行 ,特别是负荷为 40 %左右时 ,尾水管内形成了明显的旋转涡带。数值模拟得到的尾水管中压力脉动的频率 。

The unsteady swirl flow in the elbow draft tube of a Francis turbine under part load condition is investigated numerically. The method is to solve the incompressible Reynolds-averaged Navier-Stokes equations by a Finite Volume Method. Turbulence is modeled by an Algebraic Reynolds Stress model. The simulation results show that a rotating vortex rope appears when the turbine is working under part load condition especially under 40% load condition. The pressure fluctuation in the draft tube is obtained. The calculated pressure fluctuation frequency agrees with the test data.