Phase Change Phenomena on Hot Surfaces with a Variety of Wettability from Superhydrophilic to Superhydrophobic

研究了表面润湿性和粗糙度对水滴在热表面上蒸发的影响。对不同粗糙度的表面样品进行了水滴蒸发实验。所研制的实验装置可以独立控制水滴的直径、撞击速度和撞击频率。结果表明：（a）液固接触时间随撞击速度的减小而增大，随水滴直径的增大而增大;（B）水滴的最大铺展面积随表面粗糙度的增大而增大。

The present study aims to make clear the effect of surface wettability and roughness on evaporation of water drop on hot surfaces. Water drop evaporation experiment has been performed using surface samples with a variety of roughness. The experimental setup we have developed can control the diameter, impacting velocity and frequency of impinged water drops independently. The results show that(a) liquid-solid contact time increases with the decrease in impacting velocity and with the increase in drop diameter, and(b) maximum spread of water droplet increases with surface roughness.