Comparative analysis of subgrid drag modifications for dense gas‐particle flows in bubbling fluidized beds. Issue 11 (19th July 2013)

• Record Type: Journal Article
• Authors: Schneiderbauer, Simon; Puttinger, Stefan; Pirker, Stefan
• Is Part Of: AIChE journal. Volume 59:Issue 11(2013:Nov.)
• Page Start: 4077
• Page End: 4099
• Publication Date: 2013-07-19
• Subjects: Chemical engineering -- Periodicals; Génie chimique -- Périodiques; 660.28
• DOI: 10.1002/aic.14155
• Languages: English
• ISSNs: 0001-1541

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Many subgrid drag modifications have been put forth to account for the effect of small unresolved scales on the resolved mesoscales in dense gas‐particle flows. These subgrid drag modifications significantly differ in terms of their dependencies on the void fraction and the particle slip velocity. We, therefore, compare the hydrodynamics of a three‐dimensional bubbling fluidized bed computed on a coarse grid using the drag correlations of the groups of (i) EMMS, (ii) Kuipers, (iii) Sundaresan, (iv) Simonin, and the homogenous drag law of (v) Wen and Yu with fine grid simulations for two different superficial gas velocities. Furthermore, we present an (vi) alternative approach, which distinguishes between resolved and unresolved particle clusters revealing a grid and slip velocity dependent heterogeneity index. Numerical results are analyzed with respect to the time‐averaged solids volume fraction and its standard deviation, gas and solid flow patterns, bubble size, number density, and rise velocities. © 2013 American Institute of Chemical Engineers <italic>AIChE J</italic>, 59: 4077–4099, 2013</p> </abstract>