Physics of Fluids - Publications

Drop impact on hot plates: contact times lift-off and the lamella rupture

arΧiv
Soft Matter 16, 7935 (2020)

Authors

	Sang-Hyeon Lee
	Kirsten Harth
	Maaike Rump
	Minwoo Kim
	Detlef Lohse
	K. Fezzaa
	Jung Ho Je

BibTeΧ

@Article{D0SM00459F,
author ="Lee, Sang-Hyeon and Harth, Kirsten and Rump, Maaike and Kim, Minwoo and Lohse, Detlef and Fezzaa, Kamel and Je, Jung Ho",
title  ="Drop impact on hot plates: contact times{,} lift-off and the lamella rupture",
journal  ="Soft Matter",
year  ="2020",
pages  ="-",
publisher  ="The Royal Society of Chemistry",
doi  ="10.1039/D0SM00459F",
url  ="http://dx.doi.org/10.1039/D0SM00459F",
abstract  ="When a liquid drop impacts on a heated substrate{,} it can remain deposited{,} or violently boil in contact{,} or lift off with or without ever touching the surface. The latter is known as the Leidenfrost effect. The duration and area of the liquid–substrate contact are highly relevant for the heat transfer{,} as well as other effects such as corrosion. However{,} most experimental studies rely on side view imaging to determine contact times{,} and those are often mixed with the time until the drop lifts off from the substrate. Here{,} we develop and validate a reliable method of contact time determination using high-speed X-ray imaging and total internal reflection imaging. We exemplarily compare contact and lift-off times on flat silicon and sapphire substrates. We show that drops can rebound even without formation of a complete vapor layer{,} with a wide range of lift-off times. On sapphire{,} we find a local minimum of lift-off times that is much shorter than expected from capillary rebound in the comparatively low-temperature regime of transition boiling/thermal atomization. We elucidate the underlying mechanism related to spontaneous rupture of the lamella and receding of the contact area."}