Theoretical studies of solid particles in laminar and turbulent flows

The effect of particle concentration profiles in vertical two-phase tube flows was investigated. A two-fluid model and a difference method were used. It is shown that radial particle migration velocities can cause radial pressure gradients. Comparison between calculated and measured pressure profiles shows that the gravitational effect of the disperse phase can be correctly calculated. Analytical calculations and experiments on the effect of a given particle concentration distribution in laminar flow show good agreement. Calculations and experiments in turbulent flows show that concentration profile dominates fluid flow. Migration forces and phenomena leading to the establishment of radial concentration profiles are calculated with a model.