Analysis of a Small-Scale Pulsed-Fluidized Bed

Cyclical fluidization of solid particles with a gas phase can produce structured bubbling patterns; these “pulsed-fluidized beds” have recently attracted considerable attention due to efficient mixing of particles and their tunability. Previous studies have shown that bubble patterns are controlled by factors including mean velocity at the inlet, pulsing frequency, amplitude of oscillation and bed dimensions. However, experimental investigation of the effect of bubbles on granular rheology is lacking. We present a Particle Tracking Velocimetry study of a quasi-two-dimensional pulsed-fluidized bed. Using a Proper Orthogonal Decomposition, we show that a change in bubble pattern redistributes energy among the superimposed dynamic scales of particle-phase motion. Furthermore, we explore the diffusion characteristics of particles using Lagrangian data. Finally, we highlight the predictive capability of Eulerian-Lagrangian simulations using the Discrete Element Modeling code, MFiX-DEM.