Issue
EPL
Volume 80, Number 3, November 2007
Article Number 34005
Number of page(s) 5
Section Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
DOI http://dx.doi.org/10.1209/0295-5075/80/34005
Published online 17 October 2007
EPL, 80 (2007) 34005
DOI: 10.1209/0295-5075/80/34005

Shape and instability of free-falling liquid globules

É. Reyssat1, F. Chevy1, 2, A.-L. Biance1, L. Petitjean1 and D. Quéré1

1  Physique et Mécanique des Milieux Hétérogènes, UMR 7636 du CNRS, ESPCI - 75005 Paris, France
2  LKB, ENS - 24 rue Lhomond, 75005 Paris, France


received 7 September 2007; accepted in final form 11 September 2007; published November 2007
published online 17 October 2007

Abstract
The velocity of a falling raindrop depends on its size, and thus so does its shape. Here we describe the different simple shapes which model drops falling in air. While millimetric drops remain spherical, owing to the action of surface tension, drops larger than the capillary length get flattened, as sessile drops on solids. Air penetrates still larger globules, which are observed to be unstable. They inflate till they burst, generating myriads of fragments.

PACS
47.20.Ma - Interfacial instabilities (e.g., Rayleigh-Taylor).

© Europhysics Letters Association 2007