Numerical Simulation of Cavitation Flow in a Low Specific-Speed Centrifugal Pump with Different Diameters of Balance Holes

Abstract

In order to study the influence of a balance hole’s diameter on the cavitation performance of low specific-speed centrifugal pumps, a centrifugal pump with a specific speed of 0.301 was selected as the research object. The pump’s cavitation performance, distribution of cavitation vapor in the impeller, and axial force on the impeller were studied with the change in diameters of balance holes. The results show that with the increase in the diameter of balance holes, the cavitation number σ3% of the low specific-speed centrifugal pump became small, the pressure in the mechanical seal cavity dropped gradually, and the flow velocity in balance holes was reduced. As cavitation occurred in the impeller, the diameter of balance holes not only affected the absolute value of the axial force but also affected the direction of the axial force.