Leveraging Dual-Mode Vibration to Induce Horizontal Motion of Bubbles and Particles in Gas-Fluidized Granular Materials

Here we use computational fluid dynamics-discrete element method (CFD-DEM) simulations to impart horizontal vibration forces on gas-fluidized granular particles using a non-shift-symmetric, dual-mode sine wave. When the gas flow is pulsed and the bubbling is structured, the presence of a dual-mode horizontal vibration causes bubbles to shift horizontally with regularity every two gas oscillation cycles, which is due to a shift in the dense particle region beneath bubbles. By controlling bubble position, we mitigate the particle compartmentalization typically associated with structured bubbling, improving horizontal particle mixing. For constant gas flow, we find that the horizontal particle velocity is dependent on the fluidizing gas velocity, and deep layers of particles (H/dp > 150) can be transported if the bed is fluidized, while only a small layer on top of the bed is transported if the bed is de-fluidized.