The long cross-over dynamics of capillary imbibition
The long cross-over dynamics of capillary imbibition
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DOI：
10.1017/jfm.2022.248
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发表时间：
2022-03
影响因子：
3.7
通讯作者：
É. Ruiz-Gutiérrez;S. Armstrong;Simon Leveque;C. Michel;I. Pagonabarraga;G. Wells;A. Hernández-Machado;R. Ledesma‐Aguilar
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文献类型：
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作者：
É. Ruiz-Gutiérrez;S. Armstrong;Simon Leveque;C. Michel;I. Pagonabarraga;G. Wells;A. Hernández-Machado;R. Ledesma‐Aguilar
摘要自发毛细管吸胀是界面流体动力学中的一个经典问题，从微流体到农业都有广泛的应用。本文研究了吸积锋面的初始线性增长到沃什伯恩定律的类扩散增长极限的过渡时间。我们发现局部阻力源，如惯性阻力和半月板前进引起的摩擦，总是限制吸进锋的运动。这两种效应都会引起线性和类扩散状态之间生长指数的交叉。我们展示了这种交叉是如何比以前想象的要长得多——甚至比液体填充多孔介质所需的时间还要长。这种缓慢减速的动力学很可能在由润湿控制的过程中引起类似的长时间交叉现象。
Abstract Spontaneous capillary imbibition is a classical problem in interfacial fluid dynamics with a broad range of applications, from microfluidics to agriculture. Here we study the duration of the cross-over between an initial linear growth of the imbibition front to the diffusive-like growth limit of Washburn's law. We show that local-resistance sources, such as the inertial resistance and the friction caused by the advancing meniscus, always limit the motion of an imbibing front. Both effects give rise to a cross-over of the growth exponent between the linear and the diffusive-like regimes. We show how this cross-over is much longer than previously thought – even longer than the time it takes the liquid to fill the porous medium. Such slowly slowing-down dynamics is likely to cause similar long cross-over phenomena in processes governed by wetting.