Merger of a bubble and a soap film

Abstract

The coalescence of a drop into a fluid bath is a subject of continuing interest in fluid dynamics, owing to its dynamical complexity, its accessibility in the laboratory, and its aesthetic appeal. It has been known for some time that a drop gently placed on a static bath of the same fluid may initially combine only partially with the underlying bath, resulting in a daughter droplet of approximately half the diameter of the parent droplet. This process can then repeat, giving rise to the so-called “coalescence cascade” until the final droplet is small enough to be completely absorbed.