甜菜片周围的边缘：薄液膜中由润湿引起的凹坑
Fringe around a Beet Slice: Wetting-induced Dimple in a Thin Liquid Film
AI总结：
本文通过实验测量与标度分析及数值求解润滑方程，揭示了甜菜片周围薄液膜中因毛细上升吸入流形成凹坑的机制，并给出了凹坑寿命对液体性质和膜厚的依赖关系。
摘要：
当一片甜菜放在带有一薄层甜菜汁的盘子上时，可以观察到甜菜周围有一圈清晰的边缘，其颜色比其余汁液更透明。文献中的假设相互矛盾且有限，这促使我们重新审视这一现象。我们使用电动共聚焦位移传感器测量了边缘处液体表面轮廓随时间的演化。我们的发现表明，由接触线的毛细上升引起的吸入流导致在液体表面形成一个凹坑——一个小的凹形凹陷。虽然表面张力和重力倾向于抹平凹坑，但如果液膜足够薄，粘性阻力会对抗它们。我们的标度分析正确地估计了凹坑寿命对液体性质和膜厚的依赖关系。我们还通过数值求解润滑方程和Young-Laplace方程来捕捉凹坑形成的动力学过程。这项工作为一种常见现象提供了新的解释。
英文摘要：
When a slice of beet is placed on a plate with a thin layer of beet juice, one can observe a clear fringe around the beet, where the color is more translucent than the rest of the juice. The hypotheses in literature were inconsistent and limited, which motivated us to revisit this phenomenon. Using a motorized confocal displacement sensor, we measured the temporal evolution of the liquid surface profile across the fringe. Our findings suggest that a suction flow, induced by the capillary rise of the contact line, causes a dimple - a small concave depression - to form on the liquid surface. While surface tension and gravity tends to smooth out the dimple, viscous drag acts against them if the liquid film is sufficiently thin. Our scaling analysis correctly estimates the dependence of dimple lifetime on liquid properties and film thickness. We also capture the dimple formation dynamics by numerically solving the lubrication equation with the Young-Laplace equation. This work provides a new interpretation for a common phenomenon.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
