From Frictional to Viscous Behavior: Three Dimensional Imaging and Rheology of Gravitational Suspensions

TL;DR

This study investigates the flow behavior and rheology of gravitational suspensions using 3D imaging, revealing a transition from granular-like to viscous-like behavior depending on the flow rate, and confirming theoretical models.

Contribution

It provides experimental validation of rheological models for gravitational suspensions across different flow regimes using advanced 3D imaging techniques.

Findings

Slow flows mimic dry granular behavior

Faster flows align with inertial number rheology

Experimental data supports recent theoretical models

Abstract

We probe the three dimensional flow structure and rheology of gravitational (non-density matched) suspensions for a range of driving rates in a split-bottom geometry. We establish that for sufficiently slow flows, the suspension flows as if it were a dry granular medium, and confirm recent theoretical modeling on the rheology of split-bottom flows. For faster driving, the flow behavior is shown to be consistent with the rheological behavior predicted by the recently developed "inertial number approaches for suspension flows.