Numerical Model of Sedimentation/Thickening with Inertial Effects

Abstract

A numerical model of gravity sedimentation and thickening was developed from the governing two-phase flow equations for the liquid and solid phases. The inertial and gravity terms in the solid and liquid momentum equations were retained in the gravity sedimentation and thickening model. An implicit, space-staggered finite-difference algorithm was developed for the resulting coupled partial differential equations. Constitutive relationships describing the physical properties of the slurry were required to solve the numerical model. These constitutive properties describing the relationship between effective stress and porosity and between permeability and porosity were determined experimentally and by model calibration. The model was calibrated and verified using the data of dynamic porosity profiles of gravity sedimentation and thickening of kaolin suspensions in distilled water.