Peters Ivo, Snoeijer Jacco H, Daerr Adrian, Limat Laurent
Laboratoire Matière et Systèmes Complexes, UMR CNRS 7057, Université Paris Diderot, 10 rue Alice Domon et Léonie Duquet, 75205 Paris cedex 13, France.
Phys Rev Lett. 2009 Sep 11;103(11):114501. doi: 10.1103/PhysRevLett.103.114501. Epub 2009 Sep 9.
Entrainment in wetting and dewetting flows often occurs through the formation of a corner with a very sharp tip. This corner singularity comes on top of the divergence of viscous stress near the contact line, which is only regularized at molecular scales. We investigate the fine structure of corners appearing at the rear of sliding drops. Experiments reveal a sudden decrease of tip radius, down to 20 microm, before entrainment occurs. We propose a lubrication model for this phenomenon, which compares well to experiments. Despite the disparity of length scales, it turns out that the tip size is set by the classical viscous singularity, for which we deduce a nanometric length from our macroscopic measurements.
在浸润和去湿流中，夹带现象通常通过形成具有非常尖锐尖端的角来发生。这种角奇点叠加在接触线附近粘性应力的发散之上，而粘性应力的发散仅在分子尺度上得到正则化。我们研究了滑动液滴后部出现的角的精细结构。实验表明，在夹带发生之前，尖端半径会突然减小，直至20微米。我们针对这种现象提出了一个润滑模型，该模型与实验结果吻合良好。尽管长度尺度存在差异，但事实证明，尖端尺寸是由经典粘性奇点决定的，我们从宏观测量中推导出了一个纳米级的长度。
