Dispersion of particles by spontaneous interparticle percolation through unconsolidated porous media

Abstract

We have performed extensive experimental and numerical studies of spontaneous percolation of small beads through an unconsolidated porous media made with large glass beads. In this paper, an experimental setup and a fast "discrete element method" algorithm are presented to deal with large numbers of particles during our interparticle percolation phenomenon studies. In all the experimental and numerical analyses, the size ratio between the moving beads and the stable packing was chosen larger than the geometrical trapping threshold: xi_{c}=(2/sqrt[3]-1);{-1}=6.464... . We measure the longitudinal and transverse dispersion coefficients versus the height of the porous medium or the number of falling small beads. The influence of bead properties such as density, diameter, or restitution coefficients was investigated by using either steel or glass beads. The individual description of these effects and their explanations were made possible by confrontation and coupling between experimental and numerical results. Indeed, with our numerical model, individual analysis of the effects of these mechanical or geometrical parameters were made possible and carried out.

Influence of Rolling Friction Coefficient on Inter-Particle Percolation in a Packed Bed by Discrete Element Method

“…So the transverse dispersion coefficient stays constant when the size ratio D/d>14. The similar tendency is also observed in a previous work by Lomine and Oger [18]. Fig.…”

“…Then, the transverse and axial dispersion coefficients and D‖ can be defined from the time evolution of ( ) The diffusive motion of a blob of small particles is also confirmed by the previous work [18]. Furthermore, as expected, the packing bed height has little effect on the percolating particle position.…”

“…Richard et al [16] used Monte Carlo method to analyze various properties relevant to percolation. Lomine and Oger [17,18] performed experiments and discrete element method (DEM) simulation to analyze dispersion of particles through a porous structure. Rahman and Zhu [19,20] and Li et al [21] performed DEM to study the effect of particle properties on particle percolation behaviour in a packed bed.…”

Analysis of Cohesive Particle Percolation in a Packed Bed Using Discrete Element Method

“…Richard et al 15) used Monte Carlo method to analyse various properties relevant to percolation. Lomine and Oger 16,17) conducted experiments and discrete element method (DEM) studies to analyse dispersion of particles through a porous structure. Rahman and Zhu 18,19) and Li et al 20) studied the effect of particle properties on particle percolation behaviour in a packed bed using DEM.…”

Rheology of evolving bidisperse granular media

“…Segregation studies by Lominé and Oger [34,35] examined the percolation of smaller particles, diameter d 1 , draining through a static, dense granular bed of larger particles, diameter d 0 . If they are sufficiently small, d 1 ≤ d 0 /6.46, the small beads poured onto a granular bed percolate through the bed similar to a pachinko gaming machine.…”