Heterarchical Granular Dynamics

TL;DR

This paper presents a novel heterarchical stochastic model for granular media that captures phenomena like segregation and flow, validated through simulations of column collapse and silo discharge.

Contribution

It introduces an alternative heterarchical model describing stochastic void dynamics in granular flows, incorporating key phenomena like segregation and flow behavior.

Findings

Model captures both stable and flowing states of granular media.

Particle size influences flow, segregation, and mixing.

Validated with simulations of column collapse and silo discharge.

Abstract

The two most commonly used methods to model the behaviour of granular flows are discrete element and continuum mechanics simulations. These approaches concentrate on the deterministic description of particle or bulk material motion. Unlike these approaches, this paper introduces an alternative model that describes the stochastic dynamics of the void spaces under the action of gravity. The model includes several key phenomena which are observed in deforming granular media, such as segregation, mixing, and an angle of repose. These mechanisms are modelled heterarchically using both spatial and microstructural internal coordinates. Key aspects of the model include its ability to describe both stable and flowing states of granular media based on a solid fraction cut-off, and the influence of particle size on flow, segregation, and mixing. The model is validated with simulations of column collapse and silo discharge.