DEM-CFD Simulation and Experiments on the Flow Characteristics of Particles in Vortex Pumps

Abstract

Due to their outstanding anti-clogging ability, vortex pumps have been gradually promoted and applied in recent years. However, when transporting sewage containing solids, they will still encounter problems such as partial clogging, overwork wear, etc., therefore, it is particularly important to master the flow characteristics of solid particles in the vortex pump. In this paper, the Discrete Element Model-Computational Fluid Dynamics (DEM-CFD) coupled calculation method is introduced into the numerical simulation of vortex pumps and particles with diameters of 1, 2 and 3 mm and concentrations of 1% and 5%, were subjected to numerical simulation and study of the flow characteristics of the particles, then rapeseed was used to represent solid particles in tests. It was obvious that the CFD results were in good agreement with the experimental results, whereby the high speed photography experimental results of the pump inlet section show that the experimental results are consistent with the numerical simulation results. The results show that there are three typical movement tracks of solid particles in the vortex pump: in Track A particles flow through the impeller and enter the volute by the through flow, in Track B particles go directly into the volute through the lateral cavity under the influence of circulation flow and in Track C the particles enter the impeller from the front cover end area of the impeller blade inlet and then into the volute through the back half area of blade. It can be found that the particles are mainly distributed at the back of the volute.

Comparative Investigation on Hydrodynamic Performance of Pump-Jet Propulsion Designed by Direct and Inverse Design Methods

“…To exclude the effect of the number of grid cells on the simulation accuracy, meanwhile avoiding using too many computing resources caused by the excessive grids, it was necessary to conduct the grid-independence analysis of the computational domain [38][39][40]. Table 5 shows the comparison of different grid cell numbers for grid independence analysis, in which J represents advance coefficient, K T represents thrust coefficient, K Q represents torque coefficient, and η is propulsion efficiency.…”

Effect of the Volume Concentration of Binary Mixed Particles on the Flow and Wear Characteristics of Centrifugal Pumps

“…Li et al [8] used numerical simulation and experiments to verify the influence of particle concentration and particle size on the performance of a centrifugal pump and found that the influence of particle concentration on the centrifugal pump was greater than that of particle size. Gao et al [9] used the CFD-DEM coupling model to study the movement of particles in a swirl pump, and the results show that there was a rotating region of particles at the inlet of the pump. Additionally, the accuracy of the CFD-DEM coupling model was proved by comparing the experimental results with the simulation results.…”

Asymmetric Solid–Liquid Two-Phase Flow around a NACA0012 Cascade in Sediment-Laden Flow

“…To quantitatively predict the wear degree of a hydraulic turbine and pump, numerical simulation combined with a physical test has become a common research method. Based on the wear mathematical model established by the test, CFD calculation, such as solving the combined solid-liquid turbulence equation (K-ε-A P model) or directly tracking the movement of solid-phase particles by the Euler-Lagrange method, can predict the location and amount of abrasion [18][19][20][21][22][23][24][25]. However, due to the limitation of the test's accuracy or the numerical simulation model, the results obtained by these methods have some deviation from the actual motion of the solid phase.…”