A semi-empirical model was developed to predict the apparent velocity of particles falling through foams. Different foams were generated from liquids with different viscosities and surface tensions. Particles with different sizes and densities were dropped into the foam and average velocities were calculated. Based on the experimental work, the semi-empirical model was derived from an energy balance between buoyancy, drag and the energy needed for the particles to deform the bubbles in their path.
QC 20180816