Transient numerical simulation for solid-liquid flow in a centrifugal pump by DEM-CFD coupling

Abstract

The two-phase solid-liquid flow in the computational fluid dynamic (CFD) method is generally analyzed by treating the solid particles as a quasi-fluid element, but this does not take into account the effects of the physical features of the solid particles and collisions among the particles. In this study, the discrete element method (DEM) was coupled with the CFD method in order to analyze the transient two-phase solid-liquid flow in a single-stage centrifugal pump with consideration for the particle-particle and particle-structure interactions. The numerical simulation process involving EDEM and FLUENT is described. Simulations were performed for the water at 25℃ at the continuous phase together with 15% of the volume as spherical solid particles (density ρ = 1500 kg/m3) with the diameter ranging from 1 to 3 mm in a random order. The results illustrate the motion of the solid particles in the pump and their effect on the flow performance of the pump in terms of time variation in the head. The velocity fields for the two-phase flow together with the volume fraction distributions and trajectories of the solid particles in the centrifugal pump are also presented.