Water droplet impacting on overheated random Si nanowires

Micro and nanostructured surfaces can significantly improve the heat transfer capability and shift the Leidenfrost temperature of impacting droplets. In this study, the effect of overheated random Si Nanowires on impacting water droplets is presented. The cooling performance was studied in term of droplet evaporation time and surface temperature while the boiling dynamics was observed through high-speed visualization. The Si Nanowires can increase almost twice the Leidenfrost temperature compare to the similar case of plain Si surface. At the same time, the heat transfer is enhanced by widening the transition boiling region about 150 K. In this regime, the film liquid lift-off behavior is observed in the range of the We numbers studied.