液滴在倾斜表面上的固化特征研究

采用平滑铝表面为基底,以去离子水为介质,对低温条件下倾斜表面上运动液滴的固化特征进行了研究,分析了液滴的固化时间特征,并探讨了基底倾斜角、液滴体积以及基底表面浸润性对液滴固化时间的影响。结果表明：当基底倾斜角小于液滴在铝表面上的临界滑动角时,液滴固化时间保持不变;当基底倾斜角大于临界滑动角时,随着倾斜角增大,液滴固化时间变短。随着液滴体积增大,虽然湿接触面积增大,但是液滴高度也增大,液滴固化时间随之延长。基底表面的疏水性越好,液滴与固体表面的湿接触面积越少,液滴高度越高,因此液滴固化时间越长。基于传热学理论建立了双圆法模型,利用其预测运动液滴的固化时间,并将计算值与实验值进行了比较,发现两者吻合良好。

Freezing characteristics of a moving droplet on the tilted surface

The freezing behavior of a moving droplet on tilted substrates under low-temperature condition was investigated in this work. The effects of the tilted angle, drop volume, and surface wettability on the freezing time were discussed. Experimental results show that the freezing time of a droplet remained constant when the tilted angle was smaller than its critical sliding angle. When the tilted angle was greater than its critical sliding angle, the freezing time got shorter as the tilted angle became larger. In addition, the freezing time prolonged with the increase of the droplet size. Not only the wet contact area increased, but also the droplet height increased, leading to an increase in freezing time. Furthermore, it showed that the wet contact area between the droplet and the substrate decreased as the hydrophobicity of the substrate got strong. At the same time, the increased droplet height resulted in long freezing time. Based on the heat transfer, a theoretical model was proposed via a bicircular method to predict the freezing time of a droplet on the tilted substrates, which was in good agreement with the experimental results.