Dry granular avalanche impact force on a rigid wall: Analytic shock solution versus discrete element simulations

Albaba, Adel; Lambert, Stéphane; Faug, Thierry (2018). Dry granular avalanche impact force on a rigid wall: Analytic shock solution versus discrete element simulations Physical Review E, 97(5) APS 10.1103/PhysRevE.97.052903

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The present paper investigates the mean impact force exerted by a granular mass flowing down an incline and impacting a rigid wall of semi-infinite height. First, this granular flow-wall interaction problem is modeled by numerical simulations based on the discrete element method (DEM). These DEM simulations allow computing the depth-averaged quantities—thickness, velocity, and density—of the incoming flow and the resulting mean force on the rigid wall. Second, that problem is described by a simple analytic solution based on a depth-averaged approach for a traveling compressible shock wave, whose volume is assumed to shrink into a singular surface, and which coexists with a dead zone. It is shown that the dead-zone dynamics and the mean force on the wall computed from DEM can be reproduced reasonably well by the analytic solution proposed over a wide range of slope angle of the incline. These results are obtained by feeding the analytic solution with the thickness, the depth-averaged velocity, and the density averaged over a certain distance along the incline rather than flow quantities taken at a singular section before the jump, thus showing that the assumption of a shock wave volume shrinking into a singular surface is questionable. The finite length of the traveling wave upstream of the grains piling against the wall must be considered. The sensitivity of the model prediction to that sampling length remains complicated, however, which highlights the need of further investigation about the properties and the internal structure of the propagating granular wave.

Item Type:	Journal Article (Original Article)
Division/Institute:	School of Agricultural, Forest and Food Sciences HAFL > Multifunctional Forest Management
Name:	Albaba, Adel; Lambert, Stéphane and Faug, Thierry
Subjects:	G Geography. Anthropology. Recreation > GB Physical geography Q Science > Q Science (General)
ISSN:	2470-0045
Publisher:	APS
Language:	English
Submitter:	David Zimmer
Date Deposited:	12 Feb 2020 08:41
Last Modified:	22 Jun 2020 14:46
Publisher DOI:	10.1103/PhysRevE.97.052903
Uncontrolled Keywords:	Free-surface flows; Granular flows; Dry granular materials; Granular fluids; Surface gravity waves; Fluid Dynamics
ARBOR DOI:	10.24451/arbor.8175
URI:	https://arbor.bfh.ch/id/eprint/8175