Numerical Simulation and Orthogonal Design Method Research Effect of Splitter Blade's Main Geometry Factors on the Performance of Pump as Turbine

Abstract

In order to research the effect of splitter blades main geometry factors on the performance of pump as turbine, the L9(34)orthogonal design scheme has been developed based on four factors which contain the blades circumferential biasing degrees, the outlet deflection angle, the outlet diameter and the number of blade. According to this design scheme, numerical simulation of centrifugal pump (ns48) as turbine has been done. By range analysis of computational results, the best design scheme of splitter blades and the level of each factor for the primary and secondary order of turbine efficiency (the outlet deflection angle, the outlet diameter, the number of blade, and blades circumferentially biasing degrees) are obtained. The internal characteristics analysis was done on centrifugal pump (ns48) as turbine at its optimal operating conditions. The results shows, compared with conventional impeller, that the internal velocity and pressure field distribution using the design scheme of composite impeller is more reasonable.