Characteristics and dynamics of levitating millimetre-sized drops on surfaces maintained above the Leidenfrost temperature

Evaporation of liquids plays a decisive role in many engineering and industrial applications, such as spray cooling, microfluidics, and coatings. Particularly when a liquid drop is dispensed over a surface above the Leidenfrost temperature T_LF, it exhibits a vigorous phase-change behaviour coupled with deteriorating heat transfer from the surface to the drop due to the formation of a thin-isolating vapour layer. We present a numerical study of the evaporation of a millimetric drop surrounded by dry air at a temperature above T_LF. The dynamics and characteristics of the Leidenfrost drop and the interfacial heat transfer are investigated under various flow and thermal properties. A high-fidelity solver is used for a fully-resolved direct numerical simulation, employing the Level Contour Reconstruction Method to accurately capture the highly deforming liquid-gas interface. The model's capability for simulating evaporation is validated against several classical evaporation models, including the Stefan-Maxwell model.