A FRACTAL ANALYSIS OF SOLIDS MIXING IN 2-DIMENSIONAL VIBRATING PARTICLE BEDS

Using flow visualization and digital image processing we have shown ex perimentally that convective motions and mixing of particles within ve rtically vibrating two-dimensional particle beds are amenable to chara cterization by fractal properties. The time profile of a fractal dimen sion presents quantitative information on the rate and degree of mixin g. Thus, the fractal dimension has been used to show the variation in the rate of mixing along the bed height. Numerical studies based on mo lecular dynamics simulations confirmed the fractal properties of the s ystem. The effect of bed height on the regional variations in the rate of mixing is explained in terms of kinetic energy per particle. (C) 1 998 Elsevier Science S.A. All rights reserved.