Numerical Simulation of Rotating Stall in Low Specific Speed Centrifugal Pump Impeller

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Author(s) NGUYEN Xuan-linh, LAI Huan-xin
Pages 442-447
Volume 5
Issue 9
Date September, 2016
Keywords Numerical Simulation, Centrifugal Pump Impeller, Rotating Stall, Off-Design Condition, Standard K -
Abstract

Rotating stall, a phenomenon that causes flow instabilities and pressure hysteresis, can occur in centrifugal impellers, mixed impellers, radial diffusers, or axial diffusers. Base on the steady-state numerical simulation, this article will analyze the impact of the phenomenon of rotating stall to the flow field in low specific speed centrifugal pump impeller at off-design condition (Q=0.25Qd), where unstable flow most likely occurs, coupled with the standard k-  turbulence model. Results show that the significant differences are revealed between the two adjacent impeller passages. One passage is dominated by rotational effects causing high velocities along the blade pressure side (passage A). The other passage (passage B) exhibits a highly separated flow field; the other passage exhibits a highly separated flow field; in the entry section a significant stall is observed, blocking the entry and as the through-flow consequently is minimal, a relative eddy develops in the remaining part of the passage. The flow field and urbulence behavior of steady turbulence flow in the centrifugal pump impeller can be calcutlated close for steady RANS method, standard k - model. Comparisons are made with experimental results and show good agreement.

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