Drop impact behaviour on alternately hydrophobic and hydrophilic layered bead packs
Drop impact behaviour on alternately hydrophobic and hydrophilic layered bead packs
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DOI：
10.1016/j.cherd.2016.02.011
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发表时间：
2016-06-01
影响因子：
3.9
通讯作者：
Newton, Michael I.
中科院分区：
文献类型：
--
作者：
Atherton, Shaun;Polak, Daniel;Newton, Michael I.
土壤的高疏水性对土壤水文、植物生长和土壤侵蚀都有影响。以前已经对模型土壤进行了研究；由紧密堆积的玻璃球层（直径140-400 μ m）组成，以模拟雨水在防水土壤上的行为。在本研究中，对多层珠包进行了测量，以评估水滴对由不同疏水层和亲水层组成的层的相互作用。利用高速摄像机记录了水滴在头包上的冲击行为，重点记录了水滴的扩散和随后的反弹行为。从液体大理石对液滴的影响的视频中观察到，疏水颗粒在液滴周围形成一层涂层，以及它如何根据珠包内疏水和亲水层的排列而不同。通过改变液滴的释放高度，建立了冲击速度与液态大理石纹形成程度之间的关系，冲击速度越快，液态大理石纹形成程度越大。还测量了三种回弹条件之间的过渡速度；反弹、钉住和破碎，随着珠粒尺寸的增加，钉住速度整体下降。(C) 2016年作者。由Elsevier B.V.代表英国化学工程师学会出版。这是一篇基于CC BY许可（http://creativecommons.org/licenses/by/4.0/）的开放获取文章。
A high level of water repellency in soils has an impact on soil hydrology, plant growth and soil erosion. Studies have been performed previously on model soils; consisting of close packed layers of glass spheres (140-400 mu m in diameter), to mimic the behaviour of rain water on water repellent soils. In this study measurements were performed on multi-layered bead packs, to assess the interaction of water drops impacting layers consisting of different hydrophobic and hydrophilic layers. A high speed video camera was used to record the impact behaviour of water droplets on the bead packs focussing on the spreading of the droplet and the subsequent rebound behaviour of the droplet. Observations were made from the videos of the liquid marble effect on the droplet, whereby hydrophobic particles form a coating around the droplet, and how it differed depending on the arrangement of hydrophobic and hydrophilic layers within the bead pack. The droplet release height was varied in order to establish a relationship between impact velocity and the degree to which liquid marbling occurs, with higher impact speeds leading to a greater degree of liquid marbling. Measurements were also made to find the transition speeds between the three rebound conditions; rebound, pinning and fragmentation, showing an overall decrease in pinning velocity as the bead size increased. (C) 2016 The Authors. Published by Elsevier B.V. on behalf of Institution of Chemical Engineers. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).