MD Shattuck, C Bizon, PB Umbanhowar, JB Swift, HL Swinney, 2d Vertically Vibrated Granular Media: Experiment and Simulation, Powders & Grains 97, ed. RP Behringer, JT Jenkins, Powders & Grains 97:429(3) 1997. [Citations: 2]. [pdf]
We report on laboratory experiments and numerical simulations of a two-dimensional (2D) vertically oscillated granular medium. The experiment consists of a thin evacuated cell filled with 0.46 +/- 0.03 mm lead particles vibrated sinusoidally (A sin(2 pi ft)) in the vertical direction. The frequency, f, and the peak acceleration are the experimental control parameters. The event-driven simulation  reproduces all of the qualitative features the experimental observations. Specifically, as The peak acceleration is increased slightly above 1g, the layer of particles leaves the bottom of the cell for part of the cycle, but the surface remains flat. When the peak acceleration reaches a critical value of approximately 2.5g, the hat layer loses stability to a sub-harmonic standing wave. The wavelength and shape of the standing wave are similar in both the experiment and simulation. As the frequency is lowered, at constant peak acceleration, the amplitude of the standing wave becomes greater and its wavelength becomes longer.