Multiscale modeling of bubbling fluidized bed reactors using a hybrid Eulerian-Lagrangian dense discrete phase approach

The fundamental problem encountered in the bubbling fluidized bed reactors is the presence of multiscale structures which cannot be resolved by the conventional drag models. In this study, a novel hybrid Eulerian-Lagrangian dense discrete phase model (DDPM) based on energy minimization and multiscale (EMMS) drag is proposed for the first time to analyze the hydrodynamics of bubbling fluidized bed reactors with Geldart A, A/B, and B particles. By comprehensive and comparative investigations of a number of key modeling parameters (grid size, drag force, particle number per parcel, turbulence, and particle-particle restitution coefficients), our proposed DDPM-EMMS model stands out of the currently-available counterparts in terms of improved grid-independency, multiscale structures resolvability with coarser grids, better parcel-independency, and better performance with laminar treatment against turbulence.