Superstable granular heap in a thin channel.
We observed experimentally a new regime for granular flows in an inclined channel with a flow-rate-controlled system. For high flow rates, the flow occurs atop a static granular heap whose angle is considerably higher than those usually exhibited by granular heaps. The properties of such superstable heaps (SSH) are drastically affected by a change in the channel width W. This indicates that the unusual stability of these heaps can be accounted for by the flowing layer and its friction on the sidewalls. A simple depth-averaged model, assuming Coulomb friction, shows that the SSH angle scales as h/W (W being the channel width), and that grain size plays no part.
Taberlet
Nicolas
N
GMCM, Université Rennes 1, Batiment 11A, 35042 Rennes, France.
Richard
Patrick
P
Valance
Alexandre
A
Losert
Wolfgang
W
Pasini
José Miguel
JM
Jenkins
James T
JT
Delannay
Renaud
R