Computational and experimental analysis of pinch-off and scaling

Pinch-off and scaling during drop formation are studied using high-accuracy computation and ultrafast, high-resolution imaging. The interface of a water drop (viscosity mu is approximately 1 cP) is shown to overturn prior to breakup for the first time in experiments, well before the dynamics transitions from the potential flow (PF) to the inertial-viscous (IV) regime. A drop of 83% glycerol-water solution (mu is approximately 85 cP) is shown to exhibit a transition from the PF to the IV regime both computationally and experimentally. The computed value of the minimum neck radius in the latter case follows Eggers's universal solution until it becomes unstable.