三峡水轮机全流道三维流动数值模拟研究

Three-dimension numerical simulation of flow movement in integral flow path of hydraulic turbine of the Three Gorges Project

本文使用商业CFD软件FLUENT,开发了部分接口程序,进行了全流道原型水轮机三维湍流数值模拟研究,计算对象是中国水利水电科学研究院机电研究所为三峡右岸开发的水轮机模型,该水力模型有完整的模型试验资料,可用于检验计算结果。水轮机全流道三维湍流数值模拟,计算区域为包括蜗壳、固定导叶、活动导叶、转轮和尾水管的全部流道。模拟中控制方程采用了三维时均N-S方程、湍流模型采用两方程RNGk-ε模型,数值方法采用贴体坐标的有限体积法。共进行了3个开度条件下的计算,每个开度各进行4个典型工况的三维湍流流场模拟,通过数值方法求解控制方程,获得了全流道的流速和压力分布。计算结果表明流速和压力分布合理,数值计算得到的效率与试验得到的效率进行比较,结果吻合良好。

In this paper, 3-D numerical calculations are performed for flow within the integral flow path of the prototype hydraulic turbine of the Three Gorges Project. Commercial software of CFD-Fluent is applied and some interface codes have been developed. A physical model for the hydraulic turbine at the Three Gorges hydropower station fight bank is developed in the department, of Hydraulic Machinery, China Institute of Water Resources and Hydropower Research. The detailed data set of model tests can be used to check the calculation results. The computational domain of the integral flow path includes spiral case, stay vanes, guide vanes, runner and draft tube. The numerical method is proposed by basing on Reynolds-averaged Navier-Stokes equations. The RNG k-ε turbulence model in curvilinear body-fitted coordinate systems with finite volume algorithm is adopted. Numerical calculations are conducted under the conditions of 3 different guide vane openings, with 4 operating regimes for each open.ing. Pressure distribution and velocity distribution within the integral flow path are obtained. Based on the calculation, the performance of the turbine corresponding to these operation regimes is evaluated l which shows good agreement with model test.