Particle Diffusion in Slow Granular Bulk Flows

Abstract

We probe the diffusive motion of particles in slowly sheared three dimensional granular suspensions. For sufficiently large strains, the particle dynamics exhibits diffusive Gaussian statistics, with the diffusivity proportional to the local strain rate - consistent with a local, quasi static picture. Surprisingly, the diffusivity is also inversely proportional to the depth of the particles within the flow - at the free surface, diffusivity is thus ill defined. We find that the crossover to Gaussian displacement statistics is governed by the same depth dependence, evidencing a non-trivial strain scale in three dimensional granular flows.

6 pages

References in corpus (3)

• Three-dimensional imaging of colloidal glasses under steady shear
• Microfluidic rheology of soft colloids above and below jamming
• Rate Dependence and Role of Disorder in Linearly Sheared Two-Dimensional Foams

Cited by in corpus (8)

• River-bed armoring as a granular segregation phenomenon
• Modeling size segregation of granular materials: the roles of segregation, advection and diffusion
• Vortices enhance diffusion in dense granular flows
• Modelling segregation of flowing bidisperse granular mixtures varying simultaneously in size and density
• Rheology of Weakly Vibrated Granular Media
• Insights on the local dynamics induced by thermal cycling in granular matter
• Eliminating Stripe Artifacts in Light-Sheet Fluorescence Imaging
• Relaxation dynamics and long-time tails explain shear-induced diffusion of soft athermal particles near jamming