Radial displacement of a fluid annulus in a rotating Hele-Shaw cell

Citation
L. Carrillo et al., Radial displacement of a fluid annulus in a rotating Hele-Shaw cell, PHYS FLUIDS, 11(4), 1999, pp. 778-785
Citations number
22
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICS OF FLUIDS
ISSN journal
1070-6631 → ACNP
Volume
11
Issue
4
Year of publication
1999
Pages
778 - 785
Database
ISI
SICI code
1070-6631(199904)11:4<778:RDOAFA>2.0.ZU;2-Y
Abstract
The radial displacement of a fluid annulus in a rotating circular Hele-Shaw cell has been investigated experimentally. It has been found that the flow depends sensitively on the wetting conditions at the outer interface. Disp lacements in a prewet cell are well described by Darcy's law in a wide rang e of experimental parameters, with little influence of capillary effects. I n a dry cell, however, a more careful analysis of the interface motion is r equired; the interplay between a gradual loss of fluid at the inner interfa ce, and the dependence of capillary forces at the outer interface on interf acial velocity and dynamic contact angle, result in a constant velocity for the interfaces. The experimental results in this case correlate in the for m of an empirical scaling relation between the capillary number Ca and a di mensionless group, related to the ratio of centrifugal to capillary forces, which spans about three orders of magnitude in both quantities. Finally, t he relative thickness of the coating film left by the inner interface, ai, is obtained as a function of Ca. (C) 1999 American Institute of Physics. [S 1070-6631(99)02503-9].