Author(s): C Wang; J J Feng; X Q Luo; J L Lu; G J Zhu

Linked Author(s):

Keywords: Rotating stall; Centrifugal pump; CFD simulation; Stall cell; Blockage coefficient

Abstract: Rotating stall is a common unstable flow phenomenon in centrifugal pumps, which usually occurs in part-load conditions. Rotating stall will cause performance instability when the pump is running, and even excite the resonance of the whole pump system in some extreme cases. In this paper, the stall phenomena at part-load conditions have been investigated by CFD simulation for a centrifugal pump. The CFD results have been compared with the experiments, including characteristic curves, internal flow structures and corresponding frequency spectrum analyses. Furthermore, a parameter named the blockage coefficient for the pump impeller passage is put forward to quantitatively evaluate the magnitude of stall. The large-scale vortex in the stalled channel is defined as a stall cell. At the operation condition Q=0.35Q0, five rotating stall cells can be observed in the impeller, which propagate among different impeller channels with a rotating frequency lower than that of the impeller. From the frequency spectrum analysis, the main frequency of the stall cells is about 23.4% of the impeller rotational frequency, resulting in 4.68% for each stall cell. For the operation condition of Q=0.38Q0, a "stationary stall" phenomenon has been observed in the impeller passages.

DOI: https://doi.org/10.1088/1755-1315/163/1/012091

Year: 2017