Avalanche Dynamics in Wet Granular Materials

TL;DR

This study investigates avalanche behaviors in wet granular materials, revealing unique flow types, viscoplastic flow characteristics, and pattern formation, advancing understanding of wet granular dynamics.

Contribution

It introduces new observations of avalanche types and flow behaviors specific to wet media, including viscoplastic flow and coherent surface patterns.

Findings

Identification of novel avalanche types in wet granular media

Observation of viscoplastic flow with lasting contacts

Discovery of velocity-independent flow depth at high rotation rates

Abstract

We have studied the dynamics of avalanching wet granular media in a rotating drum apparatus. Quantitative measurements of the flow velocity and the granular flux during avalanches allow us to characterize novel avalanche types unique to wet media. We also explore the details of viscoplastic flow (observed at the highest liquid contents) in which there are lasting contacts during flow, leading to coherence across the entire sample. This coherence leads to a velocity independent flow depth at high rotation rates and novel robust pattern formation in the granular surface.