DIFFUSION OF 2-DIMENSIONAL PARTICLES ON AN AIR TABLE

Rapid granular flow is diffusive in character. This diffusive nature i s important in the generation of constitutive properties such as effec tive shear and bulk viscosities, effective conductivity of particle fl uctuation energy, and self-diffusion coefficients. Experiments were pe rformed in a large air-table apparatus that can sustain up to a few th ousand small, light disks just above a horizontal porous plane. Experi ments on 2D diffusion processes were performed using this apparatus. M easurements of self-diffusion coefficients and granular temperature in systems having different areal concentrations are in good agreement w ith predictions based on the kinetic theory and on numerical simulatio ns.