Modeling multiphasic flow and bubbling nonfluidized beds in water-filled sediment

Abstract The phenomenon of ascending bubbles, frequently studied in the context of fluidized beds, was employed in this study to study submerged nonfluidized beds. An experimental study was conducted to improve the understanding of gas flow phenomena in porous sediments. Images were captured via a high-speed camera to monitor the mass flow and inlet pressure of the gas passing through the granular medium inside a Hele–Shaw-type rectangular cell. The flow parameters were experimentally measured, and their Lagrangian characteristics were determined in a visual nondestructive manner, where the tracing particles constituted a bubble flow in the circulating fluid. By applying the object-following algorithm, it was possible to determine the positions of the bubbles and follow them while in motion. We developed a model of porosity and studied its effects on bubble rise and residence time. The laminar flow in saturated and unsaturated areas was detected, and the limits of the rigorous use of Darcy’s law were determined. The proposed model was satisfactorily compared with the Kozeny–Carman model. Moreover, with the determination of tortuosity, the trapped bubble rise was shown to be mainly a function of the gas saturation in the system. Compared with experimental measurements, the developed model satisfactorily described this behavior.