Abstract: In this paper, the numerical simulation of solid-liquid two-phase flow in a volute centrifugal pump was studied. Using CFD method, the entire flow passage of the pump was established. The unsteady calculation of varying flow rates, particle sizes and concentrations were carried out. Combined with traditional flow field analysis and vortex dynamics method, the internal flow field under different calculation conditions was analyzed and compared. The results showed that the increase of solid particle size and concentration will lead to the decrease of pump head, but under the design flow rate, the decrease proportion of pump head is smaller than that under the off-design conditions. Under the condition of certain concentration and flow rate, increasing or decreasing the particle size will reduce the pressure pulsation. When the particle size is constant, increasing the solid concentration will reduce the amplitude of the pressure pulsation of the unsteady flow in the volute. There is a high Q-value at the diaphragm tongue in the volute chamber, so the pressure pulsation amplitude at the diaphragm tongue is the largest under all working conditions. And there is a large range of vortex band around the volute chamber, which causes the uneven pressure pulsation in the volute chamber.

Key words: centrifugal pumplsolid-liquid two-phase flowlpressure pulsationlQ criterion