Understanding the dynamics of segregation bands of simulated granular material in a rotating drum

TL;DR

This study uses Molecular Dynamics simulations to explore how granular materials segregate into bands in a rotating drum, revealing the effects of grain size, friction, and band merging mechanisms.

Contribution

It introduces a force scheme with a constant restitution coefficient and provides new insights into oscillatory band motion and merging processes in granular segregation.

Findings

Axial segregation occurs between grains of identical material but different sizes.

Frictional properties influence the oscillatory behavior of segregation bands.

Direct imaging reveals the mechanism behind band merging.

Abstract

Axial segregation of a binary mixture of grains in a rotating drum is studied using Molecular Dynamics (MD) simulations. A force scheme leading to a constant restitution coefficient is used and shows that axial segregation is possible between two species of grains made of identical material differing by size. Oscillatory motion of bands is investigated and the influence of the frictional properties elucidated. The mechanism of bands merging is explained using direct imaging of individual grains.