Tumbling sandpiles in a fluid

Abstract

Abstract. By means of contact dynamics simulations interfaced with computational fluid dynamics, we analyze the effect of a suspending fluid on the dynamics of collapse and spread of a granular column. We find that the runout distance increases as a power law with the aspect ratio of the column and, for a given aspect ratio, it may be the same in the grain-inertial and fluid-inertial regimes but with considerably longer duration in the latter case. We show that, in both viscous and fluid-inertial regimes, this behavior results from compensation between two effects of the fluid: 1) reduction of the kinetic energy during collapse and 2) enhancement of the flow by lubrication during spread.

Rheological properties of dense granular flows

“…One strategy of ongoing researches to test further the rheology is to study the response to small perturbations of an agitated or sheared steady system [60,61]. More details on the rheological properties of slow flows will be found in [62,63].…”