Fast spreading of liquid on Leidenfrost vapor layer surface

Abstract

Previous studies found that a surface with a Leidenfrost vapor layer can effectively decrease the drag of the flow field and even increase the slip length on the boundary flow. This study investigated this phenomenon by the experiment of impact of water droplets on surfaces both with and without Leidenfrost vapor layers in the film boiling regime. The rapid spreading behaviors are dominated by the inertia of the droplet, which mainly depends on the surface with or without Leidenfrost vapor film. In the cases with higher inertia force of critical Weber numbers, this study observed that a surface with a Leidenfrost vapor film can effectively increase the wetting velocity and induce larger maximum spreading factor, especially in the case of rough surfaces.