TY - JOUR
T1 - Cavity formation by the impact of Leidenfrost spheres
AU - Marston, J. O.
AU - Vakarelski, I. U.
AU - Thoroddsen, S. T.
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/5/25
Y1 - 2012/5/25
N2 - We report observations of cavity formation and subsequent collapse when a heated sphere impacts onto a liquid pool. When the sphere temperature is much greater than the boiling point of the liquid, we observe an inverted Leidenfrost effect where the sphere is encompassed by a vapour layer that prevents physical contact with the liquid. This creates the ultimate non-wetting scenario during sphere penetration through a free surface, producing very smooth cavity walls. In some cases during initial entry, however, the liquid contacts the sphere at the equator, leading to the formation of a dual cavity structure. For cold sphere impacts, where a contact line is observed, we reveal details of the contact line pinning, which initially forms a sawtooth pattern. We also observe surface waves on the cavity interface for cold spheres. We compare our experimental results to previous studies of cavity dynamics and, in particular, the influence of hydrophobicity on the entry of the sphere.
AB - We report observations of cavity formation and subsequent collapse when a heated sphere impacts onto a liquid pool. When the sphere temperature is much greater than the boiling point of the liquid, we observe an inverted Leidenfrost effect where the sphere is encompassed by a vapour layer that prevents physical contact with the liquid. This creates the ultimate non-wetting scenario during sphere penetration through a free surface, producing very smooth cavity walls. In some cases during initial entry, however, the liquid contacts the sphere at the equator, leading to the formation of a dual cavity structure. For cold sphere impacts, where a contact line is observed, we reveal details of the contact line pinning, which initially forms a sawtooth pattern. We also observe surface waves on the cavity interface for cold spheres. We compare our experimental results to previous studies of cavity dynamics and, in particular, the influence of hydrophobicity on the entry of the sphere.
KW - cavitation
KW - contact lines
KW - transition to turbulence
UR - http://www.scopus.com/inward/record.url?scp=84864239547&partnerID=8YFLogxK
U2 - 10.1017/jfm.2012.124
DO - 10.1017/jfm.2012.124
M3 - Article
AN - SCOPUS:84864239547
VL - 699
SP - 465
EP - 488
JO - Journal of Fluid Mechanics
JF - Journal of Fluid Mechanics
SN - 0022-1120
ER -