CFD-BASED MODELLING OF BUBBLE-PARTICLE COLLISION EFFICIENCY WITH MOBILE BUBBLE SURFACE IN A TURBULENT ENVIRONMENT

Flotation modelling to date appears to have concentrated either on macroscale processes or on ideal microscale processes – there has been no attempt to integrate detailed models at different scales. In this paper, bubble-particle collision efficiency with mobile bubble surfaces in a turbulent flow is investigated from a multiscale modelling viewpoint and a general methodology for modelling of turbulent bubble-particle collision efficiency with mobile surfaces is presented. An integrated CFD-based scheme is developed. The method can also be applied to non-Newtonian slurries. Example simulations and comparisons are carried out to illustrate the method. Turbulence effects on particle-bubble collision efficiency are systematically studied using a 3D ε−k turbulence model. NOMENCLATURE E collision efficiency if hydrodynamic resistance function F total force AF added mass force BF buoyancy force mod DF modified drag force P turbulence kinetic energy F pressure gradient force k pm particle mass t iN total number of particles iN number of particles hitting the bubble r radial component bR bubble radius L iR outer radius of an annulu