Comparison of Two-Fluid Model Simulations of Freely Bubbling Three-Dimensional Gas-Fluidized Beds with Magnetic Resonance Imaging Results

Abstract

Two-fluid model (TFM) simulation predictions of bubble and particle dynamics in a 3D cylindrical fluidized bed are compared with magnetic resonance imaging (MRI) measurements from a prior study across a range of gas velocities, particle sizes, and bed heights. TFM simulations generally predict the number of bubbles and bubble diameters seen as a function of vertical position of the bubbles in the bed well; however, simulations generally predict particle speeds lower than those measured experimentally. The drag model and particle stress model used in the simulations were varied and found to have an insignificant effect on predictions of bubble dynamics but a significant effect on predictions of particle velocity distribution. Overall, this study demonstrates the importance of challenging model predictions of both particle and bubble dynamics and the ability of the prior MRI results to evaluate the accuracy of submodels, such as drag and particle stress closure relationships.