Numerical study on the performance characteristics of a high-head pump turbine based on the GEKO model

Abstract

As the most mature large-scale energy storage facility in the world, the core equipment of pumped storage power stations, the pump-turbine, is currently developing towards high head and large capacity. And the computational fluid dynamics method (CFD) is one of the most important means to research the internal flow mechanism of pump turbines and optimize the hydraulic performance. Turbulence models play an important role in the study of the flow field. Many high-performance RANS turbulence models (such as SST) cleverly combine the advantages of various models to achieve high precision, but they are not universal and their applicability and accuracy for complex flows are still limited. The Generalized k-ω (GEKO) model model may be a good choice among eddy viscosity models as users can adjust the free parameters according to their specific applications. In this study, the internal flow field of pump turbine is numerically simulated by GEKO model with various values of the separation parameter C SEP and the curvature correction parameter C CURV compared with experimental results. The calculation results show that the parameter settings of C SEP and CCURV in GEKO model have a direct impact on the numerical calculation results. The parameter modification of GEKO model has the potential to improve the adaptability and accuracy of turbulence model, and is useful for improving the engineering application of turbulence model.