Fig. 4: Side-view snapshots of cavity collapse during bubble bursting.
From: Compound jetting from bubble bursting at an air-oil-water interface
The water surfaces shown here are (a) clean, or covered by a layer of (b) 100 cSt silicone oil, h/R = 0.8, (c) 1000 cSt silicone oil, h/R = 0.8, and (d) 1000 cSt silicone oil, h/R = 1.2. The equivalent bubble radius R = 1.67 mm in the experiments. Scale bars represent 1 mm. The capillary waves during cavity collapse are progressively damped in the oily cases compared with those in the pure water case (column 4 as the zoom-in images of the blue square zones in column 2), which results in a sharper tip at the cavity nadir in the oily cases (column 3), indicating the additional damping effect from the oil layer.
