Numerical investigation on cavitation characteristics under solid–liquid two-phase conditions in a centrifugal pump

Abstract

The objective of this paper is to investigate the cavitation characteristics under solid–liquid two-phase conditions in a centrifugal pump using numerical method. The partially-averaged Navier–Stokes (PANS) model and Zwart–Gerber–Belamari (ZGB) model are improved to better predict the cavitating flow. The velocity field, the vorticity field, and the distribution of sand particles at different cavitation stages are elaborated to discuss the effect of sand particles on cavitating flow, and the entropy generation theory is applied to analyze the irreversible flow loss caused by cavitation and particles inside the pump. The results show that compared with the clear water conditions, the energy performance and cavitation performance of the centrifugal pump decrease under solid–liquid two-phase conditions. Sand particles promote the development of cavitation, but also delay the shedding of cavity. Cavity structure influences the distribution of sand particles, and the large-scale cavity will promote the sand particles move toward the center of the flow channel. Cavitation and sand particles both create a decrease in velocity and an increase in vorticity in most areas of the flow channel, which leads to an increase in irreversible flow loss.