Dynamic Leidenfrost effect: relevant time and length scales


When a liquid droplet impacts a hot solid surface, enough vapor may be generated under it to prevent its contact with the solid. The minimum solid temperature for this so-called Leidenfrost effect to occur is termed the Leidenfrost temperature, or the dynamic Leidenfrost temperature when the droplet velocity is non-negligible. We observe the wetting or drying and the levitation dynamics of the droplet impacting on an (isothermal) smooth sapphire surface using high-speed total internal reflection imaging, which enables us to observe the droplet base up to about 100 nm above the substrate surface. By this method we are able to reveal the processes responsible for the transitional regime between the fully wetting and the fully levitated droplet as the solid temperature increases, thus shedding light on the characteristic time and length scales setting the dynamic Leidenfrost temperature for droplet impact on an isothermal substrate.



Drop & bubble phenomena, Drops, Evaporation


Copyright 2016 Physical Review Letters. Recommended citation: Shirota, Minori, Michiel AJ van Limbeek, Chao Sun, Andrea Prosperetti, and Detlef Lohse. "Dynamic Leidenfrost effect: relevant time and length scales." Physical review letters 116, no. 6 (2016): 064501. DOI: 10.1103/PhysRevLett.116.064501 URL: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.064501 Reproduced in accordance with the original publisher’s licensing terms and with permission from the author(s).