speed centrifugal pump at low flow rate

 

 

LI Feng qin, LI Yi, LI Xiao jun, XIA Mi

 

(Key Laboratory of Fluid Transmission Technology of Zhejiang Province, 

Zhejiang Sci Tech University, Hangzhou 310018, China)

 

 

Abstract: Aiming at investigating flow characteristics in a low specific speed centrifugal pump at low flow rates, calculations were performed with a commercial software package, FLUENT. Turbulence was simulated with the SIMPLE algorithm based on the RNG k ε model. The grid independence was checked by applying three kinds of mesh to improve the accuracy of numerical simulation. Monitoring points were created from the impeller inlet to the suction inlet to get backflow location at different flow rates. Based on the comparative analysis of the velocity and pressure distributions, the results indicate that the streamlines of suction and impeller passages are quite smooth and the flow is stable in centrifugal pump at 0.7Qd. Vortical structures are first observed in the inlet of impeller and impeller passages at 0.6Qd. With further decreasing flow rate, the strength of backflow in impeller inlet is intensified and vortexes in impeller passages are extended to the adjacent passage. The whole flow patterns become disordered.

 

Key words: centrifugal pump; low specific speed; numerical simulation; backflow; vortex