Hydrodynamic modeling of granular flows in a modified Couette cell

TL;DR

This paper uses a continuum model to simulate dense granular flows in a modified Couette cell, successfully predicting shear band positions and behaviors consistent with experimental observations.

Contribution

It introduces a continuum model based on an inertial-number-dependent friction coefficient to simulate granular flows and predict shear band dynamics.

Findings

Model accurately predicts shear band positions.

Smooth transition in velocity profiles with height.

Shear band width increases with rotation rate.

Abstract

We present simulations of granular flows in a modified Couette cell, using a continuum model recently proposed for dense granular flows. Based on a friction coefficient, which depends on an inertial number, the model captures the positions of the wide shear bands. We show that a smooth transition in velocity-profile shape occurs when increasing the height of the granular material, leading to a differential rotation of the central part close to the surface. The numerical predictions are in qualitative agreement with previous experimental results. The model provides predictions for the increase of the shear bands width when increasing the rotation rate.