Bifurcations of a Driven Granular System under Gravity

Abstract

Molecular dynamics study on the granular bifurcation in a simple model is presented. The model consists of hard disks, which undergo inelastic collisions; the system is under the uniform external gravity and is driven by the heat bath. The competition between the two effects, namely, the gravitational force and the heat bath, is carefully studied. We found that the system shows three phases, namely, the condensed phase, locally fluidized phase, and granular turbulent phase, upon increasing the external control parameter. We conclude that the transition from the condensed phase to the locally fluidized phase is distinguished by the existence of fluidized holes, and the transition from the locally fluidized phase to the granular turbulent phase is understood by the destabilization transition of the fluidized holes due to mutual interference.

Statistical properties of granular gas under microgravity one-dimensional inelastic hard rod system

“…These facts showed that if ðN; r c Þ and G are fixed, the macroscopic properties are determined as a certain fixed value for any ðg; v; A 0 Þ. Actually, many previous studies (including the works of authors in microgravity [5,6]) have been performed by using CRC for its simplicity. However, in experimental and theoretical works, it is generally known that the restitution coefficient strongly depends on the impact velocity v imp (e.g.…”