Avalanches in cohesive granular matter
E. Freyssingeas, M.-J. Dalbe and J.-C. Géminard
We report on the intermittent dynamics of the free surface of a cohesive granular material during a silo discharge. In absence of cohesion, one observes the formation and the growth of a conical crater whose angle is well defined and constant in time. When the cohesion is involved the free surface exhibits a complex dynamics and the crater, resulting from a series of individual avalanches, is no longer axisymmetric. However, in spite of the intermittent behavior of the free surface, the flow rate is observed to remain constant throughout the discharge.
Flowers in flour: Avalanches in cohesive granular matter.
E. Freyssingeas, M.-J. Dalbe and J.-C. Géminard, Phys. Rev. E 83 (2011) 051307.