Asymptotic regimes in elastohydrodynamic and stochastic leveling on a viscous film

Christian Pedersen , John Niven , Thomas Salez (1) , Kari Dalnoki-Veress , Andreas Carlson

1 LOMA - Laboratoire Ondes et Matière d'Aquitaine

An elastic sheet that deforms near a solid substrate in a viscous fluid is a situation relevant to various dynamical processes in biology, geophysics and engineering. Here, we study the relaxation dynamics of an elastic plate resting on a thin viscous film that is supported by a solid substrate. By combining scaling analysis, numerical simulations and experiments, we identify asymptotic regimes for the elastohydrodynamic leveling of a surface perturbation of the form of a bump, when the flow is driven by either the elastic bending of the plate or thermal fluctuations. In both cases, two distinct regimes are identified when the bump height is either much larger or much smaller than the thickness of the pre-wetted viscous film. Our analysis reveals a distinct crossover between the similarity exponents with the ratio of the perturbation height to the film height.

Domaines: Dynamique des Fluides [physics.flu-dyn]; Mécanique des solides [physics.class-ph]; Mécanique des matériaux [physics.class-ph]; Mécanique des fluides [physics.class-ph]; Mécanique statistique [cond-mat.stat-mech]; Science des matériaux [cond-mat.mtrl-sci]; Matière Molle [cond-mat.soft]

Christian Pedersen, John Niven, Thomas Salez, Kari Dalnoki-Veress, Andreas Carlson. Asymptotic regimes in elastohydrodynamic and stochastic leveling on a viscous film. Physical Review Fluids, 2019, 4, pp.124003. ⟨hal-02052718v2⟩