Verification and Validation of Spatially Averaged Models for Fluidized Gas-Particle Suspensions

Abstract

Two different methods for closure modeling of the unresolved terms appearing in the filtered two-fluid model are discussed and compared. The spatially averaged two-fluid model is based on generalizing the concepts of large eddy simulation to gas-particle flows. In the approximate deconvolution method-two-fluid model approach, the unresolved terms are modeled by an approximate deconvolution method, where an approximation of the unfiltered solution is obtained by repeated filtering. Finally, these models are applied to a lab-scale and a pilot-scale fluidized bed. Both approaches yield fairly good agreement with a highly resolved reference simulation as well as with experimental data. Additionally, both methods deliver reasonable grid-independent solutions up to a grid resolution of 2 cm in the case of Geldart type A particles.