Effect of a wall boundary on the dynamics of high-Bond bubbles rising in a still liquid at different regimes
Please login to view abstract download link
We present an experimental study on bubbles rising into still liquids in the vicinity of a rigid vertical wall at high Bond numbers. In particular, three different path regimes are explored, namely rectilinear, zigzag and spiral. Experiments were conducted by recording the bubble's rising motion with two synchronized high-speed cameras. The effect of the dimensionless initial distance from the surface to the bubble, L, is investigated for each regime. The results show an increasing stabilizing effect of the surface as L decreases. This effect is most evident in the spiral regime, which even becomes a zigzag regime when the wall is close enough. Moreover, an overall migration effect from the wall is observed and characterized. Finally, in the zigzagging regimes, the bubble oscillates in a plane perpendicular to the wall when it is close enough.