Numerical simulation of solid suspension via mechanical agitation: effect of the modelling approach, turbulence model and hindered settling drag law

Abstract

This study uses the commercial CFD code ANSYS CFX to explore two different modelling approaches, Eulerian–Eulerian (E–E) and algebraic slip modelling (ASM), for the simulation of the suspension of moderately concentrated slurries (10% by volume of solids). It is shown that the ASM provides a computationally efficient model that performs very similarly to the E–E model. The influence of the choice of turbulence model (phasic or homogeneous) and the role of turbulent dispersion forces are also investigated. In addition, the importance of interfacial drag modelling and other non-drag forces are examined. During this study, the existence of inherent hindered settling in the momentum equation formulation is noted and it is shown how it can be accounted for in hindered drag law implementation.

Keywords:

• solids suspension
• hindered settling
• algebraic slip model
• Eulerian multiphase model
• drag law