(78a) An Analog of Rayleigh-Bénard Convection in Vibrated Gas-Fluidized Beds

Fluidized beds have been subject to vibration to suppress bubbling, overcome cohesive forces and structure bubbling. Here, we demonstrate that vibrating fluidized beds with a low gas velocity can produce a fluidized state in which particles form convection cells of opposing chirality in which the size of the cells does not change as the system width is increased. We demonstrate that two-fluid modeling can reproduce this phenomenon and show that the convection is caused by a balance between buoyant and effective viscous forces, analogous to Rayleigh-Bénard convection in conventional liquids. We show vibration conditions can be manipulated to control convection patterns.