Numerical investigation of pulsed fluidized bed using CFD-DEM: Insights on the dynamics
Computational Fluid Dynamics and Discrete Element Method are used to study the dynamics of a pseudo-2D pulsed fluidized bed, consisting of Geldart B particles. The focus is on the response of the system to variations in the mean gas velocity, VM, and the amplitude of oscillations, VA, at an imposed frequency of 3.5 Hz. Distinctive flow patterns are mapped out based on observation of simulations, pressure fluctuations and bubble granular temperature profiles. A regime transition is observed when VA is varied under constant VM. Such transition is underlined by: a peak in time-averaged pressure drop and coordination number; a change in the dynamics of the solid phase; an increase in velocity of the void fronts traversing the particle bed; and a decrease in minimum average height attained by the solid phase. This is related to the suppression of void layers at higher VA, occurring more easily at lower VM.
Keywords: Pulsed fluidized bed, CFD-DEM, Regime transition, Pulsation parameters, Regular bubble patterns