12th European Conference on Turbomachinery Fluid dynamics & Thermodynamics
Transient flow in pump turbines appears because the hydropower storage plant needs to experience variable operation modes to make a balance between the electricity production and consumption, thus causing high-pressure fluctuations and shortening life expectancy. In this paper, three-dimensional numerical simulation, based on Detached Eddy Simulation (DES) turbulent model, was carried out to investigate the flow characteristics in a high head pump turbine in pump mode during rapid closure of wicket gates. The dynamic mesh technique was applied to simulate the rotation of the guide vane. In this work, the influence of water compressibility on pressure fluctuations was considered. The transient flow characteristics during load reduction were investigated by time-frequency analysis methods of the numerical data.