Intermittent granular flow and clogging with internal avalanches

Intermittent Granular Flow and Clogging with Internal Avalanches

The dynamics of intermittent granular flow through an orifice in a granular bin and the associated clogging due to formation of arches blocking the outlet, is studied numerically in two-dimensions. Our numerical results indicate that for small hole sizes, the system self-organizes to a steady state and the distribution of the grain displacements decays as power laws. On the other hand, for larg...

Internal Avalanches in Models of Granular Media

We study the phenomenon of internal avalanching within the context of recently introduced lattice models of granular media. The avalanche is produced by pulling out a grain at the base of the packing and then studying the number of grains to be rearranged before the packing is stable again. We find that the avalanches are long-ranged, decaying as a power law. We study the distribution of avalan...

Stability, Avalanches, and Flow in Dry and Wet Granular Materials

Granular avalanches in fluids.

Three regimes of granular avalanches in fluids are put in light depending on the Stokes number St which prescribes the relative importance of grain inertia and fluid viscous effects and on the grain/fluid density ratio r. In gas (r>>1 and St>1, e.g., the dry case), the amplitude and time duration of avalanches do not depend on any fluid effect. In liquids (r approximately 1), for decreasing St,...

Rapid Granular Avalanches

Granular avalanches are one of the fundamental grain transport mechanisms in our natural environment and in many industrial grain-processing flows. In recent years significant progress has been made in describing the flow of granular avalanches over complex rigid topography. Often the fluid-like granular avalanches flow over a region of solid-like grains at which there may be erosion or deposit...