Numerical simulation of turbulent gas–solid flow using an approximate deconvolution model. (May 2019)

• Record Type: Journal Article
• Authors: Schneiderbauer, Simon; Saeedipour, Mahdi
• Is Part Of: International journal of multiphase flow. Volume 114(2019)
• Page Start: 287
• Page End: 302
• Publication Date: 2019-05
• Subjects: Multiphase turbulence -- Kinetic theory based two-fluid model (TFM) -- Sub-grid closure -- Structural turbulence model -- ADM regularization; Multiphase flow -- Periodicals; Écoulement polyphasique -- Périodiques; Multiphase flow; Periodicals; 620.1064
• DOI: 10.1016/j.ijmultiphaseflow.2019.03.017
• Languages: English
• ISSNs: 0301-9322

Abstract

Highlights: An approximate deconvolution model (ADM) is applied to gas-solid fluidized beds. ADM is able to reconstruct unresolved contributions when using coarse grids. Different regularization methods accounting for the sub-grid scales are evaluated. Results suggest that ADM is insensitive to the grid size for the present case. Results obtained by ADM show good agreement with highly resolved simulation data. Abstract: In our prior study (Schneiderbauer and Saeedipour, Phys. Fluids, 2018; 30:023301), an a-priori analysis on the spatially-filtered two-fluid model (TFM) was presented for turbulent gas–solid flows, where the unresolved terms were modeled by an approximate deconvolution model (ADM). With such an approach, an approximation of the unfiltered solution is obtained by repeated filtering allowing the determination of the RSFS (resolved sub-filter scales) contribution of unclosed terms of the filtered equations directly. In the present study, this ADM-TFM approach is implemented in an a-posteriori manner for the coarse grid simulation of a fluidized bed of Geldart type B particles and is verified against highly-resolved TFM simulations. Furthermore, different regularization methods, which account for the sub-filter scale (SFS) contribution, are presented and discussed with respect to their predictiveness and stability. It is shown that employing an appropriate rheological model for the solid phase considerably improves stability without removing too much energy from the resolved scales. Finally, the ADM-TFM predictions are in fairly good agreement with the fine grid reference case and do not show a notable grid-dependency. Compared to TFM simulations using the same grid resolution, the ADM-TFM approach does only require marginally more computational resources.