Numerical Simulation of Particle Sedimentation in Liquid and Experimental Verification

Fluid and unequally-sized particle (Dp=4μm and 8μm) motions in a sedimentation vessel are numerically simulated. The three-dimensional Navier-Stokes equations and the Lagrangian equations of particle motions were simultaneously solved, where the mutual interaction between fluid and particles due to drag forces, the collision among particles and the effects of cohesive forces acting on particle contact points were taken into account. The corresponding experiments were also performed. The calculated layer of sedimental particles at the bottom of vessel agreed with the experimental results when the cohesive conditions which corresponded to those of real particles were used. The calculated results of particle settling velocities are also in fairly good agreement with the experimental data. The results of this study show that our numerical simulation model makes it possible to describe the sedimentation of unequally-sized particles in liquid.