Issue
EPL
Volume 84, Number 4, November 2008
Article Number 44001
Number of page(s) 5
Section Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
DOI http://dx.doi.org/10.1209/0295-5075/84/44001
Published online 11 November 2008
EPL, 84 (2008) 44001
DOI: 10.1209/0295-5075/84/44001

Energetic approach for the characterization of taps in granular compaction

F. Ludewig, S. Dorbolo, T. Gilet and N. Vandewalle

GRASP, Physics Department B5, University of Liège - B-4000 Liège, Belgium, EU

f.ludewig@ulg.ac.be

received 27 June 2008; accepted in final form 7 October 2008; published November 2008
published online 11 November 2008

Abstract
We report numerical investigations for the compaction dynamics of dense granular assemblies. The studies are based on the non-smooth contact dynamics model. Our work suggests that the dimensionless acceleration parameter $\Gamma $, used by a large majority of authors, is not appropriate for rescaling the data. We prove that the dimensionless energy $\Xi $, injected in the granular system at lift-off, is more appropriate and leads to robust interpretations of the compaction dynamics. Indeed, the injected energy allows to pass energy barriers that separate local equilibrium states. Using the Eyring picture of relaxation dynamics, we show that the consideration of $\Xi $ leads to a new law for compaction.

PACS
45.70.-n - Granular systems.
45.70.Cc - Static sandpiles; granular compaction.
75.40.Mg - Numerical simulation studies.

© EPLA 2008