ABSTRACT
Air is known to strongly influence the dynamics of fine grains subject to vertical vibration. At low frequencies, the horizontal components of air flow lead to Faraday tilting and rapid granular convection (Faraday 1831). For binary mixtures of distinct ρd2, where ρ is the granular density and d is the grain diameter, excellent separation may occur due to the grain-fluid interaction (Burtally et al. 2002). Like particles are dragged equally by the forced air flow, while dissimilar grains are dragged apart. Local convection is found within each separated region. Global convection which would cause mixing is avoided due to gaps which open up between the separated regions over much of the vibration cycle. In this paper, we discuss the influence of air on the dynamics of binary granular mixtures subjected to vertical vibration in the differential gravity environment provided by an inhomogeneous magnetic field.
