Type
ArticleKAUST Department
Clean Combustion Research CenterHigh-Speed Fluids Imaging Laboratory
Mechanical Engineering Program
Physical Science and Engineering (PSE) Division
Date
2012-05-09Online Publication Date
2012-05-09Print Publication Date
2012-05Permanent link to this record
http://hdl.handle.net/10754/562175
Metadata
Show full item recordAbstract
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. © 2012 Cambridge University Press.Citation
Marston, J. O., Vakarelski, I. U., & Thoroddsen, S. T. (2012). Cavity formation by the impact of Leidenfrost spheres. Journal of Fluid Mechanics, 699, 465–488. doi:10.1017/jfm.2012.124Sponsors
This work was partially supported by KAUST AEA grant 7000000028.Publisher
Cambridge University Press (CUP)Journal
Journal of Fluid Mechanicsae974a485f413a2113503eed53cd6c53
10.1017/jfm.2012.124