A hybrid drag model for studying hydrodynamics in a 2D gas-solid tapered fluidized bed

The present work proposes a hybrid drag model by combining homogeneous Ergun cor-relation and heterogeneous bubble-based drag formulation. The predictions of bubble size, bubble fraction, bed expansion ratio, particulate fluidized area fraction, and solid volume fraction in a 2D gas-solid tapered fluidized bed using the hybrid, Gidaspow, and Energy Minimization Multi-Scale (EMMS) drag models have been compared with the ex-perimental results. The hybrid drag model predicts these parameters closer to the ex-perimental findings. A heterogeneous flow structure has been observed in simulations similar to experiments for the tapered fluidized bed. The bed shows larger solid volume fraction values near its periphery compared to its center. The solid particles show a central-upward and peripheral-downward flow pattern in the tapered fluidized bed.& COPY; 2023 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.