Direct Numerical Simulation of Droplets Interacting with Free Surface

Droplet interaction with free surfaces is extensively studied due to its relevance in understanding phenomena such as ocean surface salinity distributions, liquid aeration, and capillary waves. Capturing the hydrodynamics associated with multiple droplets poses challenges due to the stochastic nature of droplets. This study addresses these challenges through numerical investigation, focusing on how the vertical and horizontal distances between water droplets affect their interaction with a free surface immediately after impact. We conduct direct numerical simulations using the volume-of-fluid method to characterize the shape and position of fluid interfaces. Adaptive mesh refinement is used to reduce the computational cost needed for resolving detailed flow field dynamics. Our result is validated against previous experimental and numerical studies of droplet impact on liquid pools. In our simulations, droplets are placed close to the free surface, each initially set with a terminal velocity. We gather and visualize data from various combinations of horizontal and vertical distances between the droplets to elucidate post-impact droplet dynamics, including cavity propagation and crown development.