No abstract

Highlights  A prismatic spouted bed was modelled using CFD.  A comparison between discrete element method (CFD-DEM) and two fluid model (CFD-TFM) was performed.  Results in terms of accuracy and computational effort were evaluated for each approach.  CFD-DEM provides a better prediction of maximum particle velocity.  CFD-TFM predicts better the height of the fountain. A spouted bed was simulated through two Computational Fluid Dynamic models: CFD-TFM and CFD-DEM. The two models were compared and validated with data from literature, showing good agreement between experimental and simulated results. Both models were able to predict the dynamics of the bed from the static situation to stable spouting conditions, even though some discrepancies in the solid volume fraction or velocity profiles were observed. Overall, CFD-DEM reproduced better the experimental measurements, and, since the computational effort was proved to be similar in both cases due to the low number of particles in the bed, it was preferred to describe the present spouted bed. In larger systems, however, CFD-DEM might not be so convenient, requiring the evaluation of the degree of accuracy and the computational costs prior to the application of this or alternative models.

No abstract

No abstract

No abstract

No abstract

No abstract

A spouted bed has been simulated through a Computational Fluid Dynamic model using the Two Fluid Method and validated against experimental data. A sensitivity analysis has assessed the influence of the characteristic parameters on the solution. Among them, the accurate selection of the drag law seems to have the strongest influence on the results. In order to extend the capabilities of Ansys Fluent, Di Felice's drag law was also considered through a User Defined Function. The assessment of the granular phase and its kinetic, collisional and frictional forces, is highly relevant to achieve a correct prediction of the particle velocity profile. The specularity coefficient appears to be more influencing than the restitution coefficient, but both parameters are useful to optimise the model. Overall, the prediction of the particle vertical velocity is accurate whereas the height of the fountain is slightly over-predicted.