Spreading of a micrometric fluid strip down a plane under controlled initial conditions

J. M. GOMBA, J. DIEZ, A. G. GONZÁLEZ, R.GRATTON

PHYSICAL REVIEW E - STATISTICAL PHYSICS, PLASMAS, FLUIDS AND RELATED INTERDISCIPLINARY TOPICS

American Physical Society

Año: 2005 vol. 71 p. 163041 - 163044

1063-651X

We experimentally study the spreading of a small volume of silicon oildown a vertical plane with small Bond number. The initial condition ischaracterized by a horizontal long fluid strip with cross sectional area$A$ and width $w_0$. We find that the experiments are characterized by a unique non dimensional parameter, $Rpropto w_0^4/(a^2 A)$, where $a$ is the capillary length.An empirical criterium to estimate the onset of the contactline instability is established. The later rivulet formation at thecontact line leads to a pattern which is characterized by a dominantwavelength. We find that this wavelength is approximately proportionalto $R^{-1/4}$.