Numerical Investigation Analysis of Pressure Fluctuation Intensity of Axial Flow Pump within Stall Region

Abstract

To restrain the formation of stall, the internal flow structure of a high-specific-speed axial flow pump is predicted by transient numerical simulation. The calculated results are validated by test data. The mathematical statistical theory of standard deviation is introduced to analyze and compare the pressure fluctuation intensity (Pflu) under the design and stall operation points. The results indicate that influenced by the large-scale vortices structure within stall region, Pflu inside different flow passage components increases. In terms of the spatial distribution, the Pflu near the inflow pipe wall of the outlet increases from the enhancement of the impeller pre-rotation effect. In the impeller channel, the flow separation vortices near the leading edge of the blade and the reflux vortices at the outlet hinder the mainstream flow and cause P_flu to increase. In the guide vane channel, there are high-intensity vortices near the suction side and leading edge, resulting in an increase in P_flu.