Size Segregation and Convection of Granular Mixtures Almost Completely Packed in the Rotating Thin Box

TL;DR

This paper investigates size segregation and convection in densely packed granular mixtures within a 2D rotating thin box, reproducing phase inversion phenomena and revealing convection-driven axial segregation.

Contribution

It introduces a 2D simulation approach for densely packed granular mixtures that captures phase inversion and convection-driven segregation, extending understanding beyond previous 3D studies.

Findings

Qualitative reproduction of phase inversion in radial segregation

Observation of global convection leading to axial segregation

Simulation effectively models dense granular mixture behavior

Abstract

Size segregation of granular mixtures which are almost completely packed in a rotating drum is discussed with an effective simulation and a brief analysis. Instead of a 3D drum, we simulate 2D rotating thin box which is almost completely packed with granular mixtures. The phase inversion of radially segregated pattern which was found in a 3D experiment are qualitatively reproduced with this simulation, and a brief analysis is followed. Moreover in our simulation, a global convection appears after radial segregation pattern is formed, and this convection induces axially segregated pattern.