Author(s): J T Liu; M L Li; X P Li; L Chen; X R Lin

Linked Author(s):

Keywords: Pump-turbine; Vaneless space; Turbulence kinetic energy production; Misaligned guide vanes; Pressure fluctuation

Abstract: Unsteady flow in a high head pump-turbine was simulated using the Partially-Averaged Navier–Stokes (PANS) method. To study the improvement of “S” characteristics of a pump-turbine with misaligned guide vanes (MGV), turbulence kinetic energy production term and pressure fluctuations are numerically studied, comparing with results of pump-turbine with synchronized guide vane (SyV). Instability in the vaneless space of the model pump-turbine is analyzed based on turbulence kinetic energy equation. The maximum value of turbulence kinetic energy production (Pk) with MGV is doubled compared with the maximum value with SyV, which are in accordance with the increase of the amplitude of pressure fluctuation compared with SyV. The change of Pk is determined by the change of the normal stress term. The change of normal stress term will influence the amplitude of pressure fluctuation. The maximum value of 3D term with MGV increases compared with the result with SyV. It may be caused by the nonuniform flow with MGV.

DOI: https://doi.org/10.1088/1755-1315/163/1/012078

Year: 2017