Modeling Stratified Segregation in Periodically Driven Granular Heap Flow
Abstract
We present a continuum approach to model segregation of size-bidisperse granular materials in unsteady bounded heap flow as a prototype for modeling segregation in other time varying flows. In experiments, a periodically modulated feed rate produces stratified segregation like that which occurs due to intermittent avalanching, except with greater layer-uniformity and higher average feed rates. Using an advection-diffusion-segregation equation and characterizing transient changes in deposition and erosion after a feed rate change, we model stratification for varying feed rates and periods. Feed rate modulation in heap flows can create well-segregated layers, which effectively mix the deposited material normal to the free surface at lengths greater than the combined layer-thickness. This mitigates the strong streamwise segregation that would otherwise occur at larger particle-size ratios and equivalent steady feed rates and can significantly reduce concentration variation during hopper discharge. Coupling segregation, deposition and erosion is challenging but has many potential applications.
Cite
@article{arxiv.2208.00245,
title = {Modeling Stratified Segregation in Periodically Driven Granular Heap Flow},
author = {Hongyi Xiao and Zhekai Deng and Julio M. Ottino and Paul B. Umbanhowar and Richard M. Lueptow},
journal= {arXiv preprint arXiv:2208.00245},
year = {2022}
}