Experiments and modelling of contact line instabilities in thin liquid films

J. GOMBA; A. GONZÁLEZ; J. DIEZ; R. GRATTON; L. KONDIC

Dresden, Alemania

Workshop; International Workshop on Pattern Formation through Instabilities in Thin Liquid Films: From Fundamental Aspects to Applications; 2004

Max-Planck-Institut für Physik komplexer Systeme

We experimentally study the spreading of a small volume of PDMS oil down a vertical plane with small Bond number. The initial condition corresponds to a horizontal long fluid strip with cross sectional area A and width w0. We find that the experiments are characterized by a unique non dimensional parameter R~w0^4/(a^2 A), where a is the capillary length. An empirical criterium to estimate the onset of the contact line instability is established. The later rivulet formation at thecontact line leads to a pattern which is characterized by a dominant wavelength. We find that this wavelength is approximately proportional to R-1/4.