Multiphase flow with unequal granular temperatures

Multiphase kinetic theory has been generalized to include rotation of particles with unequal masses and diameters. Inelastic binary collisions of particles with normal and tangential restitution coefficients are considered. New expressions for number of binary collisions, viscosities and conductivities were developed. Collision integrals produced new expressions for energy dissipation involving tangential and normal restitution coefficients. Computed radial profiles of granular temperatures of 530 and 156 μm glass beads flowing in a two story riser matched the experimentally measured profiles of granular temperatures using a particle image velocity technique without rotation. The measured and the computed particle concentration profiles were nearly flat in the central portion of the riser without rotation. Computations show that rotation can alter these profiles. Sufficient particle spin can drive the particles to concentrate near the center of the tube.