Condensate droplet size distribution and heat transfer on hierarchical slippery lubricant infused porous surfaces
Condensate droplet size distribution and heat transfer on hierarchical slippery lubricant infused porous surfaces
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DOI：
10.1016/j.applthermaleng.2020.115386
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发表时间：
2020-07
影响因子：
6.4
通讯作者：
Yota Maeda;F. Lv;Peng Zhang;Y. Takata;D. Orejón
中科院分区：
文献类型：
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作者：
Yota Maeda;F. Lv;Peng Zhang;Y. Takata;D. Orejón
近年来，光滑的注入润滑剂的多孔表面（SLIPS）由于其在诸如冷凝、低摩擦、自清洁和防冰的应用中的优异性能而受到重要关注，这归因于注入的润滑剂或油的存在有效地减少了液体-固体相互作用并且当与疏水和/或超疏水表面相比时增强了液滴流动性。在这项工作中，我们制造和利用分级微/纳米结构和纳米结构的SLIPS冷凝相变。光学显微镜和宏观实验观察耦合提取液滴尺寸分布在不同的冷凝时间。通过单独的冷凝液滴的传热阻力模型在这里进一步扩展到帐户的存在下的微米和纳米结构。然后，通过单个液滴的传热耦合到液滴数密度，以估计在不同的冷凝时间和它们的整体性能的传热。据报道，与分级微米/纳米结构SLIPS相比，纳米结构SLIPS的传热性能提高了100%，这是由于微米结构和结构内存在的润滑剂所施加的更大热阻。我们的结论是，虽然微结构的存在下的液滴数密度朝着更大的人口较小尺寸的液滴，这种效果是不够的，以克服更大的传热预测上单独的纳米结构SLIPS。本文的研究结果补充了SLIPS和冷凝相变传热的现有研究，对有效设计具有强化冷凝传热性能的SLIPS具有重要意义。
In recent years, slippery lubricant infused porous surfaces (SLIPSs) have received important attention due to their excellent performance in applications such as condensation, low friction, self-cleaning and anti-icing, which is owed to the presence of an infused lubricant or oil effectively decreasing the liquid-solid interactions and enhancing droplet mobility when compared to hydrophobic and/or to superhydrophobic surfaces. In this work, we fabricate and make use of hierarchical micro-/nano-structured and nano-structured SLIPSs for condensation phase-change. Optical microscopy and macroscopic experimental observations are coupled to extract the droplet size distribution at different condensation times. Heat transfer resistance model through individual condensing droplets is further extended here to account for the presence of both micro- and nano-structures. Then, heat transfer through individual droplets is coupled to the droplet number density to estimate the heat transfer at different condensation times and their overall performance. A 100% greater heat transfer performance is reported on nano-structured SLIPSs when compared to hierarchical micro-/nano-structure SLIPSs due to the greater thermal resistance imposed by the micro-structures and the lubricant present within the structures. We conclude that although the presence of micro-structures shifts the droplet number density towards greater population of smaller sized droplets, this effect is not enough to overcome the greater heat transfer predicted on solely nano-structured SLIPSs. Findings presented here complement current research on SLIPSs and condensation phase-change heat transfer and are of great importance for the effective design of SLIPSs with enhanced condensation heat transfer performance.