Parametrical and theoretical design of a Francis turbine runner with the help of computational fluid dynamics

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.A computational fluid dynamics based design system with the integration of blade modeler, mesh generator and Navier- Stokes based CFD codes makes the design optimization of turbine components quick and efficient. This design system is applied to a low head Francis turbine runner. The parameters of turbine runner affect the hydraulic performance of turbines. Its complex parameters cause direct effect on the global parameters which change the efficiency and the output power. The purpose of this study is the investigation of the effects of theoretical turbine runner parameters on the design. To determine the parameter effects on the turbine performance theoretical calculations and analyses of turbine runner were performed. A methodology was followed with the help of CFD to reach the best efficiency operating point of turbine. Starting from the preliminary design to the final design, theoretical calculations were performed and evaluated using the results of the CFD analyses. The CFD analyses were used to visualize the flow characteristics on runner blades induced by runner parameters. At the end, a new runner model is designed with a higher efficiency.