Particle Pressures in Gas-Fluidized Beds: A Computational Fluid Element Method Study

The particle stress tensor is an indispensable part of continuum theory for gas-solid flow. In this study, computational fluid dynamics-discrete element method (CFD-DEM) simulations were performed to extract the particle stress tensor in gas-fluidized beds. It was shown that the numerically extracted particle pressures exerted on the wall are in excellent agreement with the experimental data available in the literature, thus offering a direct experimental validation of the approach that extracts the particle stress tensor using the CFD-DEM method. Furthermore, it was found that (i) bubble motion is the main source of generating particle stress, (ii) the size of the transducer has no effect on the measured particle stress on the wall, (iii) the particle pressure is approximately isotropic, and (iv) the particle stress on the wall differs significantly from that inside the bed. The present study proved that the CFD-DEM method is a powerful tool to explore the physical nature of particle phase stress