The Leidenfrost Phenomenon on Sub-Micron Tapered Pillars

In this paper, the effect of Si sub-micron tapered pillars on the Leidenfrost point of water droplets at different impact velocities is presented. In the Leidenfrost regime, the low thermal conductivity of the vapor layer deteriorates the heat transfer performance. Micro and nanostructured surfaces can significantly shift the Leidenfrost point towards higher temperatures. To determine this point, the droplet lifetime method was employed. The cooling performance was discussed in terms of the droplet evaporation time and the Weber number. It was observed that Si sub-micron tapered pillars can shift the Leidenfrost point for all the Weber numbers investigated (1–60). The displacement of the Leidenfrost point is enhanced by increasing the droplet impact velocity.