Study of unsteady cavitation flow of a pump-turbine at pump mode

Three dimensional, unsteady, cavitating flows in a pump-turbine at pump mode were numerically studied using SST k-ω turbulence model and the mixture model. The unsteady cavitating flow and pressure fluctuations at different positions were analysed with two openings of guide vanes. Calculation results are in good agreement with experimental data. Results show that the opening of guide vanes has great effect on the cavitation phenomenon. The cavitating region gradually decreases with the increase of the relative opening, and it locates at the inlet of the suction side. The amplitude of the pressure fluctuation reduces as the cavitating region decreases. The numerical study of unsteady cavitating flow can provide a basic understanding for the improvement of stable operation of a pump-turbine.