Optimal selection of blade number of hydraulic turbine based on Computational Fluid Dynamics

To select the optimal blade number of Francis turbine in small hydropower station, four typical conditions are chosen to computed for full flow of turbine based on Computational Fluid Dynamics (CFD). The 3-D flow field and stresses of a Francis turbine and the fluid-structure interaction are studied by model analysis. The results demonstrate that when the blades of the runner increases to 15 or decreases to 12, comprehensive performances of the turbine deteriorated. When the blades number reduces to 13, power of the turbine increased in main operating conditions. Its comprehensive performances are better than the original one, which demonstrates that properly reducing blades number based on comprehensive analysis can reach the effect of capacity increase.