Kink-induced transport and segregation in oscillated granular layers

TL;DR

This study investigates how kinks in oscillated granular layers cause particle segregation through convection rolls, enabling controlled collection of larger particles via experimental and simulation methods.

Contribution

It introduces a novel mechanism of particle segregation driven by kink-induced convection in oscillated granular layers, combining experiments and simulations.

Findings

Kinks trap larger particles effectively.

Convection rolls are driven by avalanches at the solid-fluid interface.

Kink position can be controlled by adjusting oscillation frequency.

Abstract

We use experiments and molecular dynamics simulations of vertically oscillated granular layers to study horizontal particle segregation induced by a kink (a boundary between domains oscillating out of phase). Counter-rotating convection rolls carry the larger particles in a bidisperse layer along the granular surface to a kink, where they become trapped. The convection originates from avalanches that occur inside the layer, along the interface between solidified and fluidized grains. The position of a kink can be controlled by modulation of the container frequency, making possible systematic harvesting of the larger particles.