title: Role of density in granular lubrication.
abstract: We investigate the dynamics of a disk shaped intruder sliding on a granular monolayer. The monolayer is on an inclined transparent plane, tilted at an angle much smaller than the angle of avalanche. A high speed camera allows us to measure the dynamics of both, the intruder (filming from top) and the grains (filming from below). We find a frictional force with a dependence on the speed of the intruder. Moreover, calculating a Reynolds-like number, it is possible to highlight the influence of the density of the beads that form the monolayer on the dynamics of the disk. We also find that the fluidization produced by the intruder's action reduces substantially the effective friction coefficient.
authors.affiliation: CINVESTAV-Monterrey, Autopista Nueva al Aeropuerto Km. 9.5, Apodaca, Nuevo León 66600, México. alfobatista@yahoo.com
authors.forename: A J
authors.initials: AJ
authors.lastname: Batista-Leyva
authors.forename: F
authors.initials: F
authors.lastname: Pacheco-Vázquez
authors.forename: J C
authors.initials: JC
authors.lastname: Ruiz-Suárez