Effect of grain shape on the jamming of two-dimensional silos

Ezequiel Goldberg,C Manuel Carlevaro,Luis A Pugnaloni,F Radjai,S Luding,S Nezamabadi,J.Y Delenne

doi:10.1051/epjconf/201714006009

Abstract

We present discrete element method simulations of the discharge of silos in two dimensions. We study the effect of the grain shape on the clogging of small apertures, considering regular polygons and disks of equal mass. In particular, we analyze the avalanche size distribution and the jamming probability for disks, triangles, squares, pentagons, hexagons and heptagons as a function of the aperture size. We show that the jamming probability presents a non-linear response as a function of the number of vertexes of the polygons.

Highlights

The clogging of the flow of grains through small apertures is usually an undesired phenomenon in different industrial processes
We study the effect of the grain shape on the clogging of small apertures, considering regular polygons and disks of equal mass
We show that the jamming probability presents a non-linear response as a function of the number of vertexes of the polygons

Summary

Introduction

The clogging (or jamming) of the flow of grains through small apertures is usually an undesired phenomenon in different industrial processes. It is generally accepted that, for spherical grains, a circular opening larger than five particle diameters will rarely clog. Whether this is a sharp transition is still under debate [1, 2]. Zuriguel et al [3] have shown that rice (elongated grains) and pasta pellets (short cylindrical grains) do present a larger tendency to jamming. Despite these initial investigations, there has not been systematic studies on the effect of particle shape on clogging. Triangular particles show a marked reduction in clogging if compared to squares, pentagons and hexagons

Simulation

Results

Conclusions