Analysis of Pressure Fluctuations in Impeller of Guide Vane Mixed-flow Pump Based on Large Eddy Simulation

In order to investigate the phenomenon of pressure fluctuations caused by unsteady flow in impeller of guide vane mixed-flow pump, 8 pressure fluctuation test points were set on impeller inlet-plane and impeller outlet-plane respectively. LES was adopted to calculate the whole flow field which includes inlet pipe, impeller, guide vane and outlet pipe, and analyze the pressure fluctuation time domain graph and spectrum graph of 8 pressure fluctuation test points. The results shows thatdue to the stall andseparate flow of rotating impeller and interaction with static guide vane, the pressure fluctuation coefficient amplitude at outlet of impeller are greater than that at inlet of impeller, and the maximum amplitude pressure fluctuation occurs at outlet of impeller, and the impulse wave decays slowly. The main frequency of pressure fluctuations at impeller inlet-plane and outlet-plane is blade frequency and blade frequency is a multiple of impeller frequency.