混流式水轮机内部流动的整体解析及气蚀预测

采用计算流体力学方法,将整个水轮机划分为蜗壳、固定导叶叶栅、活动导叶叶栅、转轮和尾水管等几个域,对混流式水轮机进行整体解析,并根据各个域的残差履历,以转轮残差的充分收敛作为迭代计算是否收敛的判据.最后以某水电厂的混流式水轮机作为研究对象,得到了混流式水轮机的静态压力场,并利用压力场预测了转轮叶片出口负压面气蚀的发生时刻及发生部位,所得结果与实际转轮出口负压面气蚀结果一致,表明了文中方法的有效性.

Lump-Sum Analysis of Internal Flow in Francis Turbine and Resulted Cavitation Prediction

The method of Computational Fluid Dynamics(CFD) is adopted to carry out a lump-sum analysis of Francis turbine.In the analysis,the turbine is divided into several regions including the spiral casing,the stay vane,the guide vane,the runner and the draft tube.According to the variation of the residual error for each region,the sufficient convergence of the residual error for the runner is used as the criterion for the iterative computation.Then,with the Francis turbine in a hydropower plant as the object,the dimensionless pressure of the turbine is obtained,which is then employed to predict the time and position of cavitation on the suction surface of the runner vane.The predicted results accord well with the practical ones,thus verifying the effectiveness of the proposed method.