Validation Study on Spatially Averaged Two-Fluid Model for Gas-Solid Flows: II. Application to Risers and Fluidized Beds

In our prior study (Schneiderbauer, AIChE J. 2017;63(8):3544-3562), a spatially averaged two-fluid model (SA-TFM) was presented, where closure models for the unresolved terms were derived. These closures require constitutive relations for the turbulent kinetic energies of the gas and solids phase as well as for the subfilter variance of the solids volume fraction. We had ascertained that the filtered model do yield nearly the same time-averaged macroscale flow behavior in bubbling fluidized beds as the underlying kinetic-theory-based two-fluid model, thus verifying the SA-TFM model approach. In the present study, a set of 3D computational simulations for validation of the SA-TFM against the experimental data on riser flow and bubbling fluidized beds is performed. Finally, the SA-TFM predictions are in fairly good agreement with experimental data in the case of Geldart A and B particles even though using very coarse grids. (C) 2018 The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers