title: Granular flows on a dissipative base.
abstract: We study inclined channel flows of sand over a sensor-enabled composite geotextile fabric base that dissipates granular fluctuation energy. We record strain of the fabric along the flow direction with imbedded fiber-optic Bragg gratings, flow velocity on the surface by correlating grain position in successive images, flow thickness with the streamwise shift of an oblique laser light sheet, velocity depth profile through a transparent side wall using a high-speed camera, and overall discharge rate. These independent measurements at inclinations between 33∘ and 37∘ above the angle of repose at 32.1±0.8∘ are consistent with a mass flow rate scaling as the 3/2 power of the flow depth, which is markedly different than flows on a rigid bumpy boundary. However, this power changes to 5/2 when flows are forced on the sand bed below its angle of repose. Strain measurements imply that the mean solid volume fraction in the flowing layer above the angle of repose is 0.268±0.033, independent of discharge rate or inclination.
authors.affiliation: Cornell University, Ithaca, New York 14853, USA.
authors.forename: Michel Y
authors.initials: MY
authors.lastname: Louge
authors.affiliation: Universite de Rennes 1, 35042 Rennes Cedex, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Valance
authors.affiliation: Faculty of Aerospace Engineering Delft University of Technology 2629 HS Delft, The Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Lancelot
authors.affiliation: Universite de Rennes 1, 35042 Rennes Cedex, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Delannay
authors.affiliation: TenCate GeoSynthetics 9, rue Marcel Paul, F-95873 Bezons CEDEX, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Artières