Eur. Phys. J. E (2007) 22: 107-109
https://doi.org/10.1140/epje/e2007-00026-9

Rapid Note

Non-Newtonian thin films with normal stresses: dynamics and spreading

Laboratoire de Physique Statistique de l'ENS, UMR8550 du CNRS, 24 rue Lhomond, 75231, Paris Cedex 05, France

^* e-mail: boudaoud@lps.ens.fr

Received: 6 October 2006
Published online: 22 March 2007

Abstract

The dynamics of a thin film on a horizontal solid substrate is investigated in the case of non-Newtonian fluids exhibiting normal stress differences, the rheology of which is strongly non-linear. Two coupled equations of evolution for the thickness of the film and the shear rate are proposed within the lubrication approximation. This framework is applied to the motion of an advancing contact line. The apparent dynamic contact angle is found to depend logarithmically on a lengthscale determined solely by the rheological properties of the fluid and the velocity of the contact line.