https://doi.org/10.1140/epje/i2004-10082-4
Dewetting processes in a cylindrical geometry
1
Grupo de Medios Porosos, Facultad de Ingenierıa, Universidad de Buenos-Aires, Paseo Colón 850, 1063, Buenos Aires, Argentina
2
Laboratoire FAST, Campus Paris-Sud, Bâtiment 502, 91405, Orsay, France
* e-mail: hulin@fast.u-psud.fr
Received:
7
September
2004
Accepted:
28
December
2004
Published online:
7
February
2005
Dewetting of liquid films of water-glycerol solutions of different viscosities has been studied experimentally in PVC cylindrical tubes. In contrast with plane surfaces, the dewetting capillary number Cavd increases with the film thickness h0 over a large part of the experimental range and follows a same global trend independent of viscosity as a function of h0. This increase is only partly explained by variations of the capillary driving force predicted in a recent theoretical work for a cylindrical geometry. An additional explanation is suggested, based on different spatial distributions of the viscous dissipation in the dewetting bump in the planar and cylindrical geometries. This mechanism is investigated for films of different thicknesses in a numerical model assuming a polynomial variation of the liquid thickness with distance in the bump region.
PACS: 68.08.Bc Wetting – / 68.03.Cd Surface tension and related phenomena – / 47.20.Gv Viscous instability – / 47.15.-x Laminar flows –
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2005