Intrinsic convection in a settling suspension

Abstract

The intrinsic convection in a settling suspension is shown to have its origins in the buoyancy of the particle-depleted layer next to the side walls. The convection is calculated using a simple model in which the particles are represented by an excluded volume and by point forces at their centres. A boundary layer approximation is developed for vessels which are much wider than the particle diameter. It is shown that the direction of the convection depends critically on assumptions about the formation of the particle-depleted layer during the placement of the suspension into the vessel.