Drop pattern resulting from the breakup of a bidimensional grid of liquid filaments
Drop pattern resulting from the breakup of a bidimensional grid of liquid filaments
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DOI：
10.1063/1.4985994
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发表时间：
2017-10-01
影响因子：
4.6
通讯作者：
Gonzalez, Alejandro G.
中科院分区：
文献类型：
--
作者：
Cuellar, Ingrith;Ravazzoli, Pablo D.;Gonzalez, Alejandro G.
由部分润湿的基底上的液体细丝形成的矩形网格在一系列破裂中演变，导致具有不同形状的液滴阵列以相当规则的二维图案分布。我们的研究集中在两个长的平行丝的硅油，这是放置在一个玻璃基板上预先涂有氟化溶液，是由另一对长的平行丝垂直交叉时产生的配置。这种网格的一个显著特征是存在两种性质不同的液滴类型。虽然在交叉点处形成一组，但其余的是交叉点之间形成的较短长丝断裂的结果。在这里，我们分析的主要几何特征的所有类型的下降，如形状的足迹和接触角分布沿着下降周边。一系列具有相似几何和物理性质的短纤维的形成使我们能够同时进行准相同的实验来研究随后的破裂。我们开发了一个简单的流体动力学模型来预测从给定初始长度和宽度的细丝产生的液滴数量。该模型能够产生对应于少量的液滴的长度间隔，其预测成功地与实验数据以及与完整的Navier-Stokes方程的数值模拟，提供了详细的时间演变的去湿运动的长丝，直到分裂成滴比较。最后，有限细丝的预测与现有的无限的理论进行了对比。出版社：AIP Publishing
A rectangular grid formed by liquid filaments on a partially wetting substrate evolves in a series of breakups leading to arrays of drops with different shapes distributed in a rather regular bidimensional pattern. Our study is focused on the configuration produced when two long parallel filaments of silicone oil, which are placed upon a glass substrate previously coated with a fluorinated solution, are crossed perpendicularly by another pair of long parallel filaments. A remarkable feature of this kind of grids is that there are two qualitatively different types of drops. While one set is formed at the crossing points, the rest are consequence of the breakup of shorter filaments formed between the crossings. Here, we analyze the main geometric features of all types of drops, such as shape of the footprint and contact angle distribution along the drop periphery. The formation of a series of short filaments with similar geometric and physical properties allows us to have simultaneously quasi identical experiments to study the subsequent breakups. We develop a simple hydrodynamic model to predict the number of drops that results from a filament of given initial length and width. This model is able to yield the length intervals corresponding to a small number of drops, and its predictions are successfully compared with the experimental data as well as with numerical simulations of the full Navier-Stokes equation that provide a detailed time evolution of the dewetting motion of the filament till the breakup into drops. Finally, the prediction for finite filaments is contrasted with the existing theories for infinite ones. Published by AIP Publishing.