Simulation of laser-induced equilibrium drop evaporation*

In a maritime environment high energy lasers frequently interact with liquid water in the form of fog, rain, or sea spray. From these interactions the laser propagation is disturbed, but at high powers the medium is also disturbed due to laser heating and liquid vaporization. Using COMSOL Multiphysics, high energy laser interaction with a single large water drop is explored in a regime where the heat rate from evaporation is in equilibrium with the energy absorption rate from the laser. Peak liquid temperatures from the drop interior are assessed and are compared with saturation temperatures to predict the onset of nucleate boiling. Simulated surface temperatures and evaporation rates are validated against experimental data from laser interactions with single acoustically levitated water drops.