Characterizing the Rheology of Fluidized Granular Matter

TL;DR

This paper investigates the rheological behavior of fluidized granular matter under secondary oscillatory forcing, revealing linear responses and model limitations at faster forcing timescales.

Contribution

It demonstrates the applicability and limitations of the GDR-Midi rheological model for fluidized granular systems subjected to oscillatory shear.

Findings

System exhibits mostly linear response with phase lag.

GDR-Midi model fits well for slow oscillations.

Model breaks down at faster forcing timescales.

Abstract

In this study we characterize the rheology of fluidized granular matter subject to secondary forcing. Our approach consists of first fluidizing granular matter in a drum half filled with grains via simple rotation, and then superimposing oscillatory shear perpendicular to the downhill flow direction. The response of the system is mostly linear, with a phase lag between the grain motion and the oscillatory forcing. The rheology of the system can be well characterize by the GDR-Midi model if the system is forced with slow oscillations. The model breaks down when the forcing timescale becomes comparable to characteristic time for energy dissipation in the flow.