[Paper in Press] Comparison of different drag models in CFD-DEM simulations of spouted beds

This is a paper published in Powder Technology with a short term visitor Filippo Marchelli from Italy.

https://doi.org/10.1016/j.powtec.2019.10.058

Comparison of different drag models in CFD-DEM simulations of spouted beds

Filippo Marchelli,^1,2 Qinfu Hou,²* Barbara Bosio,³ Elisabetta Arato³ and Aibing Yu^2,4

¹Faculty of Science and Technology, Free University of Bozen-Bolzano, 39100 Bolzano, Italy

²ARC Research Hub for Computational Particle Technology, Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia

³Process Engineering Research Team, Department of Civil, Chemical and Environmental Engineering, University of Genova, 16145 Genova, Italy

⁴Center for Simulation and Modelling of Particulate Systems, Southeast University - Monash University Joint Research Institute, Suzhou 215123, PR China

*Corresponding author. Email: Qinfu.Hou@monash.edu

Abstract

Spouted beds are commonly simulated through the Computational Fluid Dynamics – Discrete Element Method approach. The choice of the drag model is still a matter of debate, as they feature peculiar operative conditions. In this work, we simulated two spouted beds containing Geldart-D particles. We tested seven drag models: three are classic models, while four are developed through advanced computational techniques. The results indicate that the key variable is the ratio between the operative and the minimum spouting gas velocity (u/u_ms). At u=u_ms only the Gidaspow model can always predict fluidisation, but at low u/u_ms values the Beetstra model is the best compromise. For higher values, the Rong and Di Felice models behave better, while the others overestimate the particles’ velocity. These results can be useful to identify the best performing model and show there is a need for more appropriate models for spouted beds.

Keywords: Eulerian-Lagrangian approach, fluidisation, gas-solid exchange coefficient, spouted bed, user-defined function.