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.

Graphical abstractA three-dimensional computational particle fluid dynamic (CPFD) method is used to predict three granular flow experiments which have flow dynamics different from fluid flow. The CPFD method applies fluid drag, gravity, static­dynamic friction and particle collision to discrete particles and tightly couples particle momentum into solution of the fluid Naiver­Stokes equations. The CPFD numerical method predicts all three experiments well with no adjustment of parameters or empirical correlations between calculations.Figure optionsDownload full-size imageDownload as PowerPoint slide