INVESTIGADORES
GONZALEZ Alejandro Guillermo
congresos y reuniones científicas
Título:
Coating of a cylindrical fibre: Instability and drop formation
Autor/es:
A. G. GONZÁLEZ; J. A. DIEZ; R. GRATTON; D. M. CAMPANA; F. A. SAITA
Lugar:
Long Beach, California
Reunión:
Conferencia; 63rd Annual Meeting of the APS Division of Fluid Dynamics; 2010
Institución organizadora:
American Physical Society
Resumen:
The instability of a liquid layer coating a thin cylindrical wire is
studied experimentally and numerically with negligible gravity
effects.
The initial uniform film is obtained as the residual of a sliding
drop,
and the thickness measurements are performed with an anamorphic
optical
system. A primary mode grows in the early stages of the
instability, and
its wavelength $\lambda_1$ is not always in agreement with that
predicted by the linear theory, $\lambda_m$. In later stages, a
secondary mode appears, whose wavelength is half that of the primary
mode. The behavior of the secondary mode allows us to classify the
experiments into two cases, depending on whether it is linearly
stable
(case I) or unstable (case II). In case I, the amplitude of the
secondary mode remains small compared with that of the primary one,
while in case II both amplitudes may become very similar at the end.
Thus, the distance between the final drops may be quite different
from
that seen between initial protuberances. The analysis of the
experiments
allows us to define a simple criterion based on the comparison
between
$\lambda_1$ and $\lambda_m$ (see Journal of Fluid Mechanics {\bf
651}, 117 (2010)).