title: Time dependence and density inversion in simulations of vertically oscillated granular layers.
abstract: We study a layer of grains atop a plate which oscillates sinusoidally in the direction of gravity, using three-dimensional, time-dependent numerical solutions of continuum equations to Navier-Stokes order as well as hard-sphere molecular dynamics simulations. For high accelerational amplitudes of the plate, the layer exhibits a steady-state "density inversion" in which a high-density portion of the layer is supported by a lower-density portion. At low accelerational amplitudes, the layer exhibits oscillatory time dependence that is strongly correlated to the motion of the plate. We show that continuum simulations yield results consistent with molecular dynamics results in both regimes.
authors.affiliation: Physics Department, Loyola University Chicago, Chicago, Illinois 60626, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Bougie
authors.forename: Veronica
authors.initials: V
authors.lastname: Policht
authors.forename: Jennifer Kreft
authors.initials: JK
authors.lastname: Pearce