Numerical simulations of single droplet impact on a hot substrate with geometric VOF and conjugate heat transfer

The impact of droplets onto a hot substrate above the Leidenfrost temperature is numerically studied and compared to experimental results. The simulations are conducted in OpenFOAM with the publicly available T woPhaseFlow library. This library contains a solver that uses the Volume of Fluid (VOF) method with advanced curvature and interface reconstruction models. Furthermore, phase change at the liquid–gas interface and Conjugate Heat Transfer (CHT) between the fluids and the hot plate are included. All cases are simulated in 2D and 3D configurations, with the latter presenting much better agreement with the experiments when analysing the droplet residence time and the spreading diameter. Finally, insights about the vapour layer thickness during the droplet spreading are provided. Such information is not straightforward to be obtained experimentally, showing the potential of the numerical simulations in helping to understand complex processes.