Leidenfrost Point Reduction on Micropatterned Metallic Surfaces
Leidenfrost Point Reduction on Micropatterned Metallic Surfaces
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DOI：
10.1021/la302181f
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发表时间：
2012-10-23
期刊：
影响因子：
3.9
通讯作者：
in't Veld, Albertus J. Huis
中科院分区：
文献类型：
--
作者：
del Cerro, Daniel Arnaldo;Marin, Alvaro G.;in't Veld, Albertus J. Huis
当液滴沉积在超过临界温度的高温表面上时，液滴能够漂浮起来。这就是众所周知的莱登弗罗斯特效应。当表面被加热到所谓的莱登弗罗斯特点(LFP)以上时，就会发生这种现象。在莱登弗罗斯特点以上，液滴和热表面之间的蒸汽膜能够使液滴悬浮。这样的临界温度取决于几个因素。表面粗糙度是研究最多的参数之一。几乎所有文献中的实验研究都得出结论：LFP随着粗糙度的增加而增加。根据这些结果，粗糙度似乎不利于汽膜的稳定性。与这些结果形成对比的是，我们在这里展示的微图案化表面显著降低了LFP。达到LFP所需的相对于沸点的温度升高比在平坦表面上低70%。用一个简单的半经验模型定性和定量地讨论了产生这种效应的原因。这一结果可能与利用莱登弗罗斯特效应控制跌落或减少阻力的应用程序中的节能相关。
Droplets are able to levitate when deposited over a hot surface exceeding a critical temperature. This is known as the Leidenfrost effect. This phenomenon occurs when the surface is heated above the so-called Leidenfrost point (LFP), above which the vapor film between the droplet and hot surface is able to levitate the droplet. Such a critical temperature depends on several factors. One of the most studied parameters has been the surface roughness. Almost all of the experimental studies in the literature have concluded that the LFP increases with the roughness. According to these results, it seems that the roughness is detrimental for the stability of the vapor film. In contrast with these results, we present here a micropatterned surface that significantly reduces the LFP. The temperature increase, relative to the boiling point, required to reach the LFP is 70% lower than that on the flat surface. The reasons for such an effect are qualitatively and quantitatively discussed with a simple semiempirical model. This result can be relevant to save energy in applications that take advantage of the Leidenfrost effect for drop control or drag reduction.