A simple and general sub-grid drag model for gas–solid fast fluidization

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 421; p. 129922
• Main Authors: Hu, Shanwei, Liu, Xinhua
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2021
• Subjects: Computational fluid dynamics; Drag coefficient; EMMS; Fluidization; Meso-scale structure; Meso-scale structure; Fluidization; Computational fluid dynamics; Drag coefficient; EMMS
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2021.129922

•A simple and general sub-grid drag model is proposed based on the EMMS model.•The simple model is Galileo-invariant and avoids rebuilding Hd correlations case by case.•The proposed Hd correlation can be adopted unalterably for a broad operation range.•Using the drag model correctly predicts bed hydrodynamics for various conditions. Great efforts have been paid to improve the Energy Minimization Multi-Scale (EMMS) model to better predict heterogeneous gas–solid flow using coarse-grid computational fluid dynamics (CFD) simulation. Nevertheless, the adopted drag correction factor (Hd) in the simulation was generally subject to macroscopic operating conditions (e.g., superficial gas and solid velocities, Ug and Gs), which called for rebuilding the Hd correlation if Ug or Gs varied. In this work we simplified the EMMS sub-grid model by replacing the stability condition with an equivalent cluster voidage correlation, thus making the model possess the Galilean invariance and avoiding the recalculation of Hd in case of varying operating conditions. The pre-constructed drag correction factor can facilitate the coarse-grid CFD simulation of gas–solid fast fluidization within a broad operation range.