Flow of a granular material through a forest of obstacles
Résumé
The inclined plane configuration is ideal for studying the rheology of granular materials under imposed-pressure conditions. We investigate this
situation when a forest of obstacles is present in the path of the grains and thus affects the global flow properties of the material. Our experimental
set-up consists of a plane which includes a forest of cylindrical pillars planted perpendicular to the plane and positioned at regular intervals. We
quantified the influence of the inter-pillar distance on the stationary flow rate of the grains for different layer thicknesses and different angles of
inclination. We observe that when the inter-pillar distance is reduced, the flow rate of the grains decreases and reaches a new regime where the
flow rate is practically independent of the thickness of the grain layer. In order to rationalize these observations, we develop a model that is based
on a depth-averaged approximation associated with the µ(I)-rheology and that considers the average force exerted by the pillars on the granular
layer. This approach yields an effective rheology of the system composed by grains and obstacles and that depends on the ratio between the
distance between the pillars and their diameter.
Domaines
Physique [physics]
Origine : Fichiers produits par l'(les) auteur(s)