Comparative analysis of numerically derived drag models for development of bed expansion ratio correlation in a bubbling fluidized bed.

• A bed expansion ratio correlation is proposed based on extensive numerical simulations. • Effect of various numerically derived drag models on gas-solid flow dynamics is quantitatively assessed. • Simulation results agree with experimental data reasonably well. • The corrected correlation improves the prediction by the empirical equation. For designing and operating fluidized bed reactors, bed expansion ratio is one of the most important parameters. In this research, a bubbling fluidized bed is simulated using three-dimensional Eulerian-Eulerian method that is incorporated with kinetic theory of granular flow (KTGF) to calculate the pressure drop, gas volume fraction (GVF) and bed expansion ratio. Grid optimization is firstly conducted to achieve suitable solution for further simulations. Subsequently, different numerically derived drag models are employed to investigate the effect of these models on gas-solid flow dynamics. Afterwards, the fluidized bed is simulated at different gas superficial velocities employing two different drag models respectively. Simulation results have been comprehensively validated against experimental data. Finally, an expression for bed expansion ratio has been formulated and compared with the empirical correlation. The proposed correlation holds reasonably well with various experimental values. This work provides a scalable way to aid in designing and operating process reactors. [ABSTRACT FROM AUTHOR]