Numerical Analysis of Single-Particle Motion Using CFD-DEM in Varying-Curvature Elbows

Abstract

Centrifugal pumps are the critical components in deep-sea mining. In order to investigate the particle motion in the curved channel of the impeller, three different types of curvature conform to blade profile to simplify the impeller design of pumps. A numerical study is conducted to investigate the flow field in a varying-curvature channel for solid-liquid two-phase flow. The flow of particles within the varying curvature channel is studied by combining the discrete element method (DEM) with computational fluid dynamics (CFD) and a comparison with Particle Image Velocimetry (PIV) test results. The results show that a polyhedral mesh with a small mesh number yields very accurate results, which makes it very suitable for CFD-DEM. Based on this method, the movement of a single particle is compared and analyzed, and the particle-motion law is obtained. The effects of the curvature ratio Cr and area ratio Ar on the motion law for a single particle are studied, and the simulation results are analyzed statistically. The results show that the effect of Cr on both the particle slip velocity and the turbulent kinetic energy only changes its strength, while the distribution law does not change significantly. Compared with the curvature ratio Cr, the area ratio Ar has a greater impact on the particles, and its distribution law becomes clearly different. As the area ratio Ar increases, the arc radius and length of the corresponding particle trajectory decrease.

Development of Hydraulic Lifting System of Deep-Sea Mineral Resources

“…It was found by Wang [49] et al that the particle size mainly affects the vortex strength in the pump, and has a limited impact on the hydraulic performance after the calculation and analysis of the solid-liquid two-phase unsteady flow of a single-stage deep-sea mining lifting pump based on CFD-DEM. Ning [50] analyzed and compared the CFD-DEM calculation results with the particle velocity test results (Particle Image Velocimetry (PIV)), and when the grid was dense enough, the simulation results were very close to the experiments, which fully verified that CFD-DEM was effective in simulating particles Accuracy and reliability of kinetics. Deng [27] artificial particle distribution, particle dynamics, and slurry hydraulic performance through CFD-DEM, and compared the experiment, and found that the error of CFD-DEM coupling simulation of slurry hydraulic performance can be controlled within 2%.…”