Rasuceanu Ioana, Patrascu Claudiu
Hydraulics Department, POLITEHNICA Bucharest, Bucharest, 060042, Romania.
Sci Rep. 2025 Jun 4;15(1):19611. doi: 10.1038/s41598-025-04826-3.
We investigate the spontaneous capillary imbibition of water in tubes that contain a silicone oil slug. The capillary flow is studied as a function of the silicone oil slug's viscosity, volume and position in the capillary tube. The system was found to advance with constant velocity on short distances, which can serve as a tool for estimating the effective surface tension. When the silicone oil is situated at an arbitrary distance from the tube's entrance, the air gets trapped during water imbibition, creating a gas bubble. The latter starts flowing and the more viscous phase drains via a thin film deposited on the tube's inner wall. The silicone oil slug is collected at the advancing interface separating the two immiscible liquids. Using a classical deposition law we develop an approximate model for the draining process of the silicone oil. The time of total liquid recovery can be approximated with satisfactory precision, especially for low-viscosity silicone oils.
我们研究了含有硅油段塞的管中自发的水的毛细管吸液现象。研究了毛细管流动与硅油段塞的粘度、体积以及在毛细管中的位置之间的函数关系。发现该系统在短距离内以恒定速度推进，这可作为估算有效表面张力的一种工具。当硅油位于距管入口任意距离处时，水吸液过程中空气会被困住，形成气泡。气泡开始流动，粘度较大的相通过沉积在管内壁上的薄膜排出。硅油段塞在分隔两种不混溶液体的推进界面处聚集。我们利用经典的沉积定律建立了一个硅油排出过程的近似模型。总液体回收时间可以以令人满意的精度进行近似，特别是对于低粘度的硅油。
