Assessment of drag models for geldart a particles in bubbling fluidized beds

In order to accurately predict the hydrodynamic behavior of gas and solid phases using an Eulerian-Eulerian approach, it is crucial to use appropriate drag models to capture the correct physics. In this study, the performance of seven drag models for fluidization of Geldart A particles of coal, poplar wood, and their mixtures was assessed. In spite of the previous findings that bode badly for using predominately Geldart B drag models for fine particles, the results of our study revealed that if static regions of mass in the fluidized beds are considered, these drag models work well with Geldart A particles. It was found that drag models derived from empirical relationships adopt better with Geldart A particles compared to drag models that were numerically developed. Overall, the Huilin-Gidaspow drag model showed the best performance for both single solid phases and binary mixtures, however, for binary mixtures, Wen-Yu model predictions were also accurate.