Relaxation of nonspherical sessile drops towards equilibrium

Vadim Nikolayev (1, 2, 3) , Daniel Beysens (4, 2, 3)

1 SPEC - UMR3680 - Service de physique de l'état condensé
2 SBT - Service des Basses Températures
3 ESEME : Équipe du Supercritique pour l'Environnement, les Matériaux et l'Espace : Équipe commune CEA-CNRS (2000-2014)
4 PMMH - Physique et mécanique des milieux hétérogenes (UMR 7636)

We present a theoretical study related to a recent experiment on the coalescence of sessile drops. The study deals with the kinetics of relaxation towards equilibrium, under the action of surface tension, of a spheroidal drop on a flat surface. For such a nonspherical drop under partial wetting conditions, the dynamic contact angle varies along the contact line. We propose a new nonlocal approach to the wetting dynamics, where the contact line velocity depends on the geometry of the whole drop. We compare our results to those of the conventional approach in which the contact line velocity depends only on the local value of the dynamic contact angle. The influence on drop dynamics of the pinning of the contact line by surface defects is also discussed.

Mots clés: Theoretical study; Sessile drops; Coalescences

Domaines: Mécanique des fluides [physics.class-ph]

Vadim Nikolayev, Daniel Beysens. Relaxation of nonspherical sessile drops towards equilibrium. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2002, 65 (4), ⟨10.1103/PhysRevE.65.046135⟩. ⟨hal-01261470⟩