Phase change and droplet dynamics for a free falling water droplet

This paper numerically examines phase change of free falling droplets in a sub-zero environment. The model is based on the solution of the Navier-Stokes equations coupled with the Volume of Fluid (VOF) methodology for tracking the droplet-air interface. A 2D axisymmetric model is adopted to implement the influential numerical parameters. The phase change phenomenon of fresh and salt water droplets with constant and variable properties are considered in this model. Current results reveal that the internal circulation enhances heat transfer to the surrounding air and increases the nucleation phenomenon. Furthermore, larger sized droplets have a higher nucleation temperature than the smaller sized droplets. The computational results are compared to previously published experimental data for nucleation and droplet dynamics. The results of this paper provide new insights on phase change and droplet dynamics and contribute to the understanding of mechanisms involved with spray freezing applications.