Fig. 4: Onset of periodic motion in a two-core emulsion.
From: The vortex-driven dynamics of droplets within droplets
In a–c \({\rm{Re}}\simeq 3\) and Ca ≃ 0.52, while in b–d \({\rm{Re}}\simeq 1.2\) and Ca ≃ 0.2. Red arrows indicate the direction of the fluid flow in the lab frame (a and b), and in the external droplet frame (c and d). Green arrows in a and b denote the direction, perpendicular to the flow, along which the droplet 1 starts its motion, while white arrows in c and d bespeak the direction of the fluid recirculations.
