A Numerical Study on the Effect of the Backflow Hole Position on the Performances of a Self-Priming Pump

Abstract

A self-priming pump is a centrifugal pump that has the ability to prime itself. Typically, its performance depends on the configuration of its reflux hole. In this study, the ANSYS FLUENT software is used to investigate the effects of three different radial positions of the reflux hole on gas-liquid two-phase distribution, pressure pulsation, and imp during self-priming. The research results indicate that: (1) The effective channel size for the reflux liquid to enter the volute varies depending on the location of the reflux hole. The effect of the impeller rotation on the reflux liquid becomes more obvious as the setting distance of the reflux aperture decreases. (2) The position of the reflux hole significantly affects the gas phase mass fraction inside the impeller, resulting in a significant reduction in the time it takes for the mass fraction to exceed 80%. (3) The position of the reflux hole significantly affects the average pressure on each monitoring surface. (4) Placing the reflux hole at a excessively distant radial distance can result in an excessive vertical component. (5) The self-priming performance of the pump can be improved to some extent by placing the return hole at a small radial distance.