Brownian granular flows down heaps
arXiv:1908.10762 · doi:10.1103/PhysRevLett.123.248005
Abstract
We study the avalanche dynamics of a pile of micrometer-sized silica grains in water-filled microfluidic drums. Contrary to what is expected for classical granular materials, avalanches do not stop at a finite angle of repose. After a first rapid phase during which the angle of the pile relaxes to an angle , a creep regime is observed where the pile slowly flows until the free surface reaches the horizontal. This relaxation is logarithmic in time and strongly depends on the ratio between the weight of the grains and the thermal agitation (gravitational Péclet number). We propose a simple one-dimensional model based on Kramer's escape rate to describe these Brownian granular avalanches, which reproduces the main observations.
arXiv commentarXiv admin note: substantial text overlap with arXiv:1710.09111
References in corpus (11)
- Compaction dynamics of a granular media under vertical tapping
- Frictionless bead packs have macroscopic friction, but no dilatancy
- Granular Avalanches in Fluids
- Jamming, Yielding and Rheology of Weakly Vibrated Granular Media
- The Statistical Physics of Athermal Materials
- Disentangling glass and jamming physics in the rheology of soft materials
- Creep motion of a granular pile induced by thermal cycling
- Extended sedimentation profiles in charged colloids: the gravitational length, entropy, and electrostatics
- Fluctuations of power injection in randomly driven granular gases
- Athermal analogue of sheared dense Brownian suspensions
- Spreading of a granular droplet