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

• A structure-based drag model of non-empirical drag coefficients was proposed.
• The model correctly predicted the flow behaviors in TFBs with Geldart A and B particles.
• The non-uniform structures in both the radial and axial directions were simulated.
• There is no obvious difference between Geldart A and B particles in the simulation.
• The solid distribution in radial would be more uniform with the increase of the bed diameters.

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.

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