Hydrodynamics of macroscopic particles in slurry suspensions

Abstract

© 2016 Curtin University of Technology and John Wiley & Sons, Ltd. Slurry systems in mineral processing processes often behave as pseudo-plastic fluids, where the viscosity of the slurry changes as a function of the shear imparted. Thus, characterizing motion of macroscopic objects through such systems is a challenging task because the viscous forces on it vary rapidly. In this paper, we have studied motion of falling spherical particles in non-Newtonian fluid using a novel macroscopic particle model (MPM). The simulation results were compared with the available experimental data and analytical correlations, where MPM was found to be effective in accurately determining the forces acting on particle during fluid-particle interaction. Thus, it was concluded that MPM is a computationally viable solution for resolving hydrodynamics of macroscopic particles in slurries, especially for its ability to accurately capture the acceleration of particles, which is significantly lower when compared with that in Newtonian fluids. The validated MPM model was used to investigate the effect of particle properties on the motion of particle and yield-structure of fluid. For low Reynolds number, the well-known toroidal yielded structure of fluid was observed with particle equator as centre and v2dp diameter. Beyond the Reynolds number to Bingham number ratio of 10, a wake was formed behind the particle that increased with increasing Reynolds number.