Eulerian-Eulerian Simulations of Segregating Binary Gas-Solid Fluidized Beds

This work is aimed at investigating a bidisperse gas-solid fluidized bed by Computational Fluid Dynamics simulations. The selected simulation approach is based on the Eulerian unsteady equations of motion for each phase coupled with a model based on the granular kinetic theory. The effect of grid size and time step on axial segregation of two different binary solid mixtures is investigated. The analysis of the simulation results, which strengthen previous findings with new data, confirms that firm conclusions on the capacity of the CFD model to predict the segregation dynamics in fluidized beds can be drawn only after careful verification of numerical uncertainties at the operating conditions under investigation. The relationship between the average absolute error, which is evaluated by comparison of the simulation results with literature experimental data, and a global parameter, which takes into account both the operating conditions and the spatial and temporal resolutions, is shown.