Investigation on wear induced by solid-liquid two-phase flow in a centrifugal pump based on EDEM-Fluent coupling method

Centrifugal pump is the key equipment to conveying solid-liquid two-phase mixtures, and the abrasive wear caused by solid particles is of great importance to the structural integrity of pumps. In order to investigate effects of solid-phase properties on the internal flow characteristics of the pump, especially reveal the wear mechanism of solid particles on the wall surface, the coupling method of Fluent and EDEM was adopted to study the solid-liquid two-phase flow inside the pump, and the Euler-Lagrange model was employed for numerical simulation. Calculations clearly showcased the dynamic distribution of particles and their collision scenarios, which were then verified by the Particle Image Velocimetry (PIV) experiment. It was observed that, under high flow rate schemes, particles are prone to agglomeration in the flow channel, forming a long wear strip at the tail of pressure surface blade, while wear is barely discovered on the suction side of the blade. When large-sized particles are transported, particle concentration at the pump inlet has a significant impact on the wall abrasion, more severe wear is expected to be seen with higher particle concentration. Moreover, compared with the transmission of clean water medium, the additional particles reduce the turbulent kinetic energy within the pump, especially under low flow rate. The current results can obtain accurate wear locations and shed a light in improving hydraulic performance of centrifugal pumps.