Investigating the jamming of particles in a three-dimensional fluid- driven flow via coupled CFD-DEM simulations

HL Sun and SL Xu and XD Pan and L Shi and XY Geng and YQ Cai, INTERNATIONAL JOURNAL OF MULTIPHASE FLOW, 114, 140-153 (2019).

DOI: 10.1016/j.ijmultiphaseflow.2019.01.017

The clogging of a dense stream of particles when passing through an orifice occurs ubiquitously in both natural and industrial fields. Since most of the jamming phenomena lead to the negative effects, studying and preventing jamming is of great importance. There are two typical types of jamming due to different types of driving force: (a) gravity-driven jamming and (b) fluid-driven jamming. Among these two types of jamming, the fluid-driven jamming occurs in fluid-driven particle flows, and the initial solid concentration, the fluid velocity, and the orifice- particle size ratio has been demonstrated to have effects on the occurrence of this jamming. Although the individual influence of the initial solid concentration and orifice-particle size ratio on jamming has been studied, the coupled effects of these two factors on jamming are little known. In addition, the complex effects of the fluid velocity on jamming have not been fully discussed. To address these problems, this work performs a three-dimensional simulation of the fluid-driven jamming using the coupled Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) model. At first, the jamming probability under different initial conditions is studied. The jamming probability is displayed on the solid concentration-orifice size ratio plane to illustrate the coupled effects of these two factors on jamming. The simulation results show that the critical solid concentration, at which the jamming probability increases to 1, increases with the orifice- particle size ratio. This is because an orifice with a larger orifice size ratio has a greater particle discharge capacity, which allows more particles to pass through without jamming. Then, we reveal the influence of fluid velocity over a wide range on the fluid-driven jamming type, jamming probability and shape of the jamming dome. To the author's knowledge, this is the first time that the shape of the jamming dome has been related to the fluid velocity. The jamming dome formed in the higher-speed flow has a greater curvature due to the greater fluid drag acting on the particles. (C) 2019 Published by Elsevier Ltd.

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