Creeping Avalanches of Brownian Granular Suspensions

Antoine Bérut (1, 2) , Olivier Pouliquen (1, 2) , Yoel Forterre (1, 2)

1 IUSTI - Institut universitaire des systèmes thermiques industriels
2 CNRS - Centre National de la Recherche Scientifique

We study the avalanche dynamics of a pile of micron-sized silica grains in miniaturized rotating drums filled with water. Contrary to what is expected for classical granular materials, the avalanches do not stop at a finite angle of repose. Below an angle θ_c, we observe a creep regime where the piles slowly flow until they become flat. In this regime, the relaxation is logarithmic in time and is slower when the ratio between the weight of the grains and the thermal agitation is increased. We propose a simple 1D model based on Kramer's escape rate to describe this flow.

Mots clés: dense suspensions; granular materials; brownian motion; avalanche dynamics; creep flow; rotating drum experiments

Domaines: Matière Molle [cond-mat.soft]

Antoine Bérut, Olivier Pouliquen, Yoel Forterre. Creeping Avalanches of Brownian Granular Suspensions. 2017. ⟨hal-01622814v1⟩