Experimental investigation and numerical modelling of density-driven segregation in an annular shear cell
Abstract
Granular materials segregate spontaneously due to differences in particle size, shape, density and flow behaviour. In this paper we experimentally investigate density-difference-driven segregation for a range of density ratios and a range of heavy particle concentrations. The experiments are conducted in an annular shear cell with rotating bumpy bottom that yields an exponential shear profile. The cell is initially filled with a layer of light particles and an upper layer of heavier grains and, on top, a load provides confinement. The segregation process is filmed through the transparent side-wall with a camera, and the evolution of particle concentration in space and time is evaluated by means of post-processing image analysis. We also propose a continuum-approach to model density-driven segregation. We use a segregation-diffusion transport equation, constitutive relations for effective viscosity and friction coefficient, and a segregation velocity analogous to the Stokes' law. The model, which is validated by comparison with experimental findings, can successfully predict density-driven segregation at different density ratios and volumetric fraction.
Keywords
Cite
@article{arxiv.2105.01351,
title = {Experimental investigation and numerical modelling of density-driven segregation in an annular shear cell},
author = {Monica Tirapelle and Andrea Santomaso and Patrick Richard and Riccardo Artoni},
journal= {arXiv preprint arXiv:2105.01351},
year = {2021}
}