Photonic acceleration and coalescence dynamics of microdroplets

Droplet coalescence plays a vital role in processes ranging from rainfall formation to fuel combustion. Understanding and controlling collision-induced coalescence in sprays presents an opportunity to manipulate spray dynamics effectively. This talk explores the feasibility of using photon flux to accelerate microdroplets, induce collisions, and enhance coalescence, with the overarching goal of influencing spray behavior in cloud systems through photonic forces.

By leveraging the momentum transfer from light to droplets, this study investigates a novel approach to droplet manipulation. Key experimental stages include acoustic levitation of microdroplets (5–150 µm) to assess photonic acceleration limits, photonically driven collision and coalescence at low Weber numbers (We < 0.01), and laser-induced modifications to spray dynamics in a controlled cloud chamber. Additionally, impinging spray jets were examined to assess droplet growth mechanisms near stagnation environment (i.e., at low velocity environment).

This research provides experimental validation of photon flux-driven droplet coalescence and offers insights into its governing mechanisms. The findings suggest potential applications in atmospheric science, spray control, and artificial rain generation, highlighting the broader impact of photonic forces in modifying droplet interactions.