Implementation, validation and application of a lubrication force model in CFD-DEM simulations

Numerical simulations using CFD-DEM (Computational Fluid Dynamics-Discrete Elements Method) are used to investigate the hydrodynamic behavior of the phases in solid-liquid fluidized beds. However, some challenges are posed to the prediction of energy dissipation and bed expansion on these systems-little knowledge on the collision effects on the solid phase and the high computational cost of assessing the dissipative effects of the lubrication force resulting from the liquid phase. In this context, the present study assessed the collision effects based on the coefficient of restitution, the main parameter of contact between the particles, and the influence of the lubrication force on the dynamics of a fluidized bed. For this, a lubrication force model was implemented in an open-source software CFDEM (R) project. The model was tested for collisions with fluids of different viscosities and showed good agreement with experimental data. Furthermore, the model was applied to the simulation of a fluidized bed using a high viscosity liquid and dense particles and the results indicated that the lubrication force had a significant impact on the bed dynamics, influencing the fraction of voids, porosity and particle velocity. [GRAPHICS]