Numerical Performance Prediction for a Francis Turbine Based on Computational Fluid Dynamics Stage Simulation

Based on Reynolds equations closed by k-e 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.