Droplet breakup and size distribution in an airstream: Effect of inertia

Our study experimentally investigates the morphology and breakup of a droplet descending into an airstream, analyzing child droplet size distributions through high-speed shadowgraphy and in-line holography. We found that varying the droplet's release height results in different breakup modes --- from vibrational to retracting bag-stamen breakup at the same Weber number --- each with distinct size distributions. Our theoretical model, which incorporates the effective Weber number, accurately predicts these distributions, underscoring the critical impact of droplet dynamics and aerodynamic interactions on breakup behavior.