VOF-DEM simulation of single bubble behavior in gas–liquid–solid mini-fluidized bed

[Display omitted] •Formation and rise of single bubble in mini-fluidized was simulated.•Simulations were validated by experiments with good agreements.•Interactions between bubble and particles were explored.•Bubble wake size reduced with the increase of solid holdup in the simulation. The single bubble behavior in a 3 mm rectangular gas–liquid–solid mini-fluidized bed with 90 μm particles was simulated using the combination of VOF and DEM, and the results were validated by experiments. The simulation on the expansion of liquid–solid mini-fluidized shows that the profiles of liquid and particle velocities are consistent, and both become more concentrated as the expansion ratio decreases. The bubble formation size does not change with the increase of the solid holdup from 0.25 to 0.45, while the bubble rise velocity becomes lower. The upward liquid velocity in the bubble wake exceeds 50% of the instantaneous bubble velocity. The size of the low particle concentration bubble wake reducing with the increase of solid holdup can be attributed to the decrease in the bubble rise velocity and the enhancement in the inertia effect of the liquid–solid flow.