Leidenfrost Granular Flows

Nicolas Taberlet (1, 2) , Patrick Richard (1, 3) , Renaud Delannay (1)

1 IPR - Institut de Physique de Rennes
2 DAMTP - Department of Applied Mathematics and Theoretical Physics
3 IFSTTAR - Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux

This paper presents numerical findings on rapid 2D and 3D granular flows on a bumpy base. In the supported regime studied here, a strongly sheared, dilute and agitated layer spontaneously appears at the base of the flow and supports a compact packing of grains moving as a whole. In this regime, the flow behaves like a sliding block on the bumpy base. In particular, for flows on a horizontal base, the average velocity decreases linearly in time and the average kinetic energy decreases linearly with the travelled distance, those features being characteristic of solid-like friction. This allows us to define and measure an effective friction coefficient, which is independent of the mass and velocity of the flow. This coefficient only loosely depends on the value of the micromechanical friction coefficient whereas the influence of the bumpiness of the base is strong. We give evidence that this dilute and agitated layer does not result in significantly less friction. Finally, we show that a steady regime of supported flows can exist on inclines whose angle is carefully chosen.

Domaines: Autre [cond-mat.other]

Nicolas Taberlet, Patrick Richard, Renaud Delannay. Leidenfrost Granular Flows. Traffic and Granular Flow '07, 2007, Paris, France. pp.565-576, ⟨10.1007/978-3-540-77074-9_61⟩. ⟨hal-00994713⟩