Experimental study on the unsteady evolution mechanism of centrifugal pump impeller wake under solid–liquid two-phase conditions: Impact of particle concentration

To study the spatiotemporal evolution process of particle wakes behind the impeller in the centrifugal pump, this paper utilized high-speed photography to capture the particle motion characteristics under different solid-phase particle concentrations (1%, 1.5%, and 2%). First, this paper studies the changes in hydraulic performance of the centrifugal pump under solid–liquid two-phase flow conditions. It then introduces the evolution process of the impeller particle wake, comparing the differences in particle wake evolution under varying solid-phase concentrations. Finally, the impact of the solid-phase concentration on the wear of the volute's partitions is investigated. This study found that as the solid-phase particle concentration increases, the hydraulic performance of the pump gradually declines. Under the design conditions, when the solid-phase concentration increases by 0.5%, the efficiency of the centrifugal pump decreases by 0.56% and 0.35%. There is mutual transport of particles between adjacent wakes, and the movement of particle wakes within the volute passage is not equidistant over time. As the solid-phase particle concentration increases, wake cutting occurs at the volute partitions, and there is a significant solid–liquid separation between the particle wakes. The spatial evolution of the particle wakes is significantly influenced by the solid-phase concentration. Wear at the volute partitions intensifies with increasing solid-phase concentration and is also affected by changes in the particle wakes. The research results provide a basis for further exploration of the solid–liquid two-phase flow dynamics within centrifugal pumps.