Effect of Drag Models on the Numerical Simulations of Bubbling and Turbulent Fluidized Beds

Granular option enabled two-fluid model coupled with different homogeneous and heterogeneous drag correlations, i.e., Gidaspow, Syamlal and O'Brien, Beetstra, Brucato, Gibilaro, energy minimization multiscale method (EMMS), and Tenneti, are employed for the prediction of bubbling and turbulent fluidized-bed characteristics. Numerically predicted results are validated against the literature data in terms of bubble shape and diameter, axial and radial variation of time-averaged void fraction, pressure drop, and bed expansion. The Gidaspow, Syamlal and O'Brien drag model-predicted mean void fraction and bubble shapes are close to the experiments in bubbling and turbulent fluidized beds with both the 2D and 3D geometries. All drag models overpredicted the pressure drop at low superficial gas velocities in a turbulent fluidized bed.

Automated summary

Different drag models were used to predict bubbling and turbulent fluidized-bed characteristics, showing close agreement with experimental results in terms of bubble shape and pressure drop, but overestimating pressure drop at low gas velocities.