title: Partition instability in water-immersed granular systems.
abstract: It is well known that a system of grains, vibrated vertically in a cell divided into linked columns, may spontaneously move into just one of the columns due to the inelastic nature of their collisions. Here we study the behavior of a water-immersed system of spherical barium titanate particles in a rectangular cell which is divided into two columns, linked by two connecting holes, one at the top and one at the bottom of the cell. Under vibration the grains spontaneously move into just one of the columns via a gradual transfer of grains through the connecting hole at the base of the cell. We have developed numerical simulations that are able to reproduce this behavior and provide detailed information on the instability mechanism. We use this knowledge to propose a simple analytical model for this fluid-driven partition instability based on two coupled granular beds vibrated within an incompressible fluid.
authors: School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
authors: C P
authors: CP
authors: Clement
authors: H A
authors: HA
authors: Pacheco-Martinez
authors: Michael R
authors: MR
authors: Swift
authors: P J
authors: PJ
authors: King