Abstract
When a solid plate is withdrawn from a partially wetting liquid, a liquid layer dewets the moving substrate. High-speed imaging reveals alternating thin and thick regions in the entrained layer in the transverse direction at steady state. This paper systematically compares this situation to the reversed process, forced wetting, where a solid entrains an air layer along its surface as it is pushed into a liquid. To quantify the absolute thickness of these steady-state structures precisely, I have developed an optical technique, taking advantage of the angle dependence of interference, combined with a method based on a maximum-likelihood estimation. The data show that the thicknesses of both regions of the film scale with the capillary number, . Further, an additional region is observed during onset, the quantitative explanation of which requires future investigation.
11 More- Received 31 October 2019
- Accepted 11 August 2020
DOI:https://doi.org/10.1103/PhysRevFluids.5.114001
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