Numerical Study on the Effect of Blade Trailing Edge Filing on Performance and Unsteady Pressure Pulsation in Low Specific Speed Centrifugal Pump

Purpose The change of blade trailing edge shape will affect the wake structure of impeller outflow, which has a significant impact on pressure pulsation in the pump. To study the influence of blade trailing edge shape on performance and pressure pulsation in centrifugal pump, the blade trailing edges are filed and studied with different shapes, including original trailing edge (OTE), arc-shaped pressure side filing (APS), arc-shaped suction side filing (ASS), linear pressure side filing (LPS), and linear suction side filing (LSS). Method In the present study, each scheme is established with SST k - ω turbulence model, 25 monitor points are arranged in the circumferential direction of the impeller outlet, and CFD is conducted to analyze the effect of the blade trailing edge filing on the performance and unsteady pressure pulsations of low specific speed centrifugal pump. Results Results show that the suction side filing of the blade trailing edge, especially for the ASS scheme, can significantly improve the head of the model pump. All filing schemes can reduce pressure pulsation, and the contribution of linear filing on the blade trailing edge is better than that of arc-shaped filing. By comparing the mean pressure fluctuation amplitude of the five schemes, the LPS scheme contributes obviously to pressure pulsations reduction. The axial vortex distribution shows that the filing schemes have a positive impact on reducing vortex intensity at the blade trailing edge. Conclusions The rotor–stator interaction may be reduced after filing the blade trailing edge, which will result in a lower pressure pulsation amplitude, and it is thought to be the primary cause of the pressure pulsation reduction. These findings will help to further optimize the shape of blade trailing edge.