基于雷诺时均N—S方程和标准κ-ε双方程湍流模型,对混流式水轮机全流道的三维定常湍流的48个工况点进行了计算。捕捉到了水轮机各过流部件内及动静部件间的流动细节和旋涡的结构与演化特征等重要流动信息。在全流道三维定常湍流计算的基础上,建立了基于N-S方程的混流式水轮机性能预估方法。预估的能量性能与试验结果相符。结果表明所提出的混流式水轮机性能预估方法应用于水轮机的水力设计和改造中,可以减少模型试验次数和缩短产品开发周期。而且此种性能预估方法不但可预估水轮机的性能,同时还可获得水轮机各过流部件内的流场信息,能从定量和定性两个方面评价水轮机的性能。
Based on Reynolds equations closed by κ-ε turbulence model with general coordinates,numerical simulation of three-dimensional turbulent flow through a Francis turbine was conducted for 48 different operation points. The flow field structures and the characteristics of swirling flow and its developing process in the Francis turbine were gained by the CFD full stage simulation. In the same time, a performance prediction method based on CFD full stage simulation was put forward and an efficiency hill chart was gained numerically by using of the performance prediction method. Numerical results were compared to experimental results from a model test and all important performance features were in good agreement with the simulations. It can be concluded that the presented performance prediction method is very important and available for decreasing the model runner test times and shortening product development period. Furthermore the performance of the Francis turbine could be analyzed quantitatively and qualitatively based on the presented performance prediction method.