Internal and surface waves in vibrofluidized granular materials: Role of cohesion

TL;DR

This study uses numerical simulations to explore how cohesion affects wave phenomena in vibrofluidized granular materials, revealing that cohesion suppresses surface wave formation due to reduced momentum transfer.

Contribution

It demonstrates that cohesive interactions modeled via velocity-dependent restitution suppress surface waves, aligning with experimental results and providing a quantitative understanding of impact dynamics.

Findings

Cohesion suppresses surface wave formation in granular media.

Wetting reduces momentum transfer during particle impacts.

Numerical results agree with experimental observations.

Abstract

Wave phenomena in vibrofluidized dry and partially wet granular materials confined in a quasi-two-dimensional geometry are investigated with numerical simulations considering individual particles as hard spheres. Short ranged cohesive interactions arising from the formation of liquid bridges between adjacent particles are modeled by changing the velocity dependent coefficient of restitution. Such a change effectively suppresses the formation of surface waves, in agreement with previous experimental observations. The difference in pattern creation arises from the suppressed momentum transfer due to wetting and it can be quantitatively understood from an analysis of binary impacts.