Instantaneous velocity profiles during granular avalanches.
We perform experimental measurements of the instantaneous velocity profile of the flowing layer during granular avalanches. In the pile depth, the velocity profile follows a pure exponential decrease in contrast with steady flows that are known to exhibit a well developed upper linear part. The velocity profile in the pile width is a plug flow with two exponential boundary layers at the walls. Even though no steady state is observed during the avalanche, these velocity profiles are self-similar and build up almost instantaneously, with time independent characteristic lengths.
du Pont
Sylvain Courrech
SC
Laboratoire Fluides, Automatique, Systémes Thermiques (UMR CNRS 7608), Bâtiment 502, Campus Universitaire, 91405 Orsay Cedex, France.
Fischer
Raphaël
R
Gondret
Philippe
P
Perrin
Bernard
B
Rabaud
Marc
M