“…Several approaches to such problems based on the representation of the interfaces by hypersurfaces (here called sharp interface models) are available, among which we mention interface tracking methods [44,47,53,58,59,75], volume-of-fluid methods [5,42,45,61], and ALE methods [10,32,80], see also the books [14,38]. In general, the fluid-fluid interfaces undergo changes of topology, which may manifest as the breakup of droplets, pinching, coalescence, or cusp formation or tip-streaming driven by Marangoni forces.…”