Three fundamental granular flow experiments and CPFD predictions

Granular flow of three granular flow experiments is predicted by a computational particle fluid dynamic CPFD numerical scheme in three dimension using the true particle size distribution. The experiments are simple which show the characteristics of particle flow which differs from fluid flow. The experiments are flow of particles in sedimentation, a U-tube and from a hopper. The CPFD method models the fluid as a fluid and models the particles as discrete particles (material description). The CPFD method is a form of discrete element method, where each particle has three-dimensional forces from fluid drag, gravity, static–dynamic friction, particle collision and possibly other forces. However, unlike DEM models which calculate particle-to-particle force by a spring–damper model and direct particle contact, the CPFD method models collision force on each particle as a spatial gradient. The CPFD numerical method predictions compare well with all three experiments with no adjustment of parameters or empirical correlations between calculations.