How does an air film evolve into a bubble during drop impact?

When a liquid drop impacts a solid surface, air is generally entrapped underneath. Using ultrafast x-ray phase-contrast imaging, we directly visualized the profile of an entrapped air film and its evolution into a bubble during drop impact. We identified a complicated evolution process that consists...

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Bibliographic Details
Published inPhysical review letters Vol. 109; no. 20; p. 204501
Main Authors Lee, Ji San, Weon, Byung Mook, Je, Jung Ho, Fezzaa, Kamel
Format Journal Article
LanguageEnglish
Published United States 13.11.2012
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Summary:When a liquid drop impacts a solid surface, air is generally entrapped underneath. Using ultrafast x-ray phase-contrast imaging, we directly visualized the profile of an entrapped air film and its evolution into a bubble during drop impact. We identified a complicated evolution process that consists of three stages: inertial retraction of the air film, contraction of the top air surface into a bubble, and pinch-off of a daughter droplet inside the bubble. Energy transfer during retraction drives the contraction and pinch-off of a daughter droplet. The wettability of the solid surface affects the detachment of the bubble, suggesting a method for bubble elimination in many drop-impact applications.
ISSN:1079-7114
DOI:10.1103/PhysRevLett.109.204501