PRESSURE FLUCTUATION ANALYSIS OF INTERNAL FLOW FIELD OF AXIAL-FLOW PUMP BASED ON BOUNDARY DATA IMMERSION METHOD

Axial-flow pump is a widely used fluid machinery, and the pressure fluctuation in the flow field is the key factor affecting its stable operation. The pressure fluctuation can cause the vibration and noise of the pipe and accessories. The purpose of this paper is to reveal the pressure pulsation characteristics of the unsteady flow field in axial-flow pumps. The relationship between the flow and pressure pulsation of the axial-flow pump was analyzed by the numerical approach with Immersed Boundary Data Method. For the turbulence closure mode, Large-eddy simulation (LES) is employed to the numerical simulation of the unsteady flow field of the axial-flow pump. Due to suction, there is a significant low pressure near the shroud at the impeller inlet. In the low-pressure part of the impeller outlet, a significant low pressure occurs in the middle of the blade. The pressure fluctuation amplitude of the impeller inlet section is larger than that of the impeller outlet. At the impeller outlet, the middle of the blade occurs back-flow phenomenon because of the differences in pressure distribution. The distribution of pressure is more disordered at span 50% of the impeller outlet, resulting in an obvious variation in the pressure pulsation amplitude.