Only under certain conditions does a drop falling onto a bath entrap an air bubble. We propose a phenomenological law that describes these bubbling conditions in terms of Froude, Weber, and capillary numbers.
Figure. Superimposed images of a drop and the cavity it forms on impact with a bath. Depending on the experimental conditions, a bubble may or may not form.
Reference
Bubble entrapment by drop impact: combined effect of surface tension and viscosity
PHYSICAL REVIEW FLUIDS 9, 094002 (2024)