A structure-based drag model for the simulation of Geldart A and B particles in turbulent fluidized beds

To simulate the hydrodynamics of turbulent fluidized beds (TFBs), the flow structure of the TFBs was divided into quasi discrete cluster and void phases. Then, nine local structural parameters were used to describe the internal flow structure of TFBs and these structural parameters were obtained by solving momentum conservation equation, mass conservation equation and pressure balance equation. The structure-based drag model was incorporated into the two-fluid model to simulate the gas-solid flow behavior in the TFBs, considering the effect of the non-uniform flow structure. Considering different particle types and bed diameters, four cases were set to demonstrate the effectiveness and adaptability of this model. The reasonable agreement between the simulation results and the experiment data showed that the method adopted in this work could effectively predict the gas-solid flow behavior in TFBs with Geldart A and B particles. Besides, the non-uniform structures in both radial and axial directions were successfully simulated. Meanwhile, there is no obvious difference between Geldart A and B particles. The solid concentration difference between the wall and the center region decreases with the increase of the bed diameters. (C) 2015 Elsevier B.V. All rights reserved.