Capillary filling with pseudo-potential binary Lattice-Boltzmann model

Abstract

We present a systematic study of capillary filling for a binary fluid by using a mesoscopic lattice Boltzmann model for immiscible fluids describing a diffusive interface moving at a given contact angle with respect to the walls. The phenomenological way to impose a given contact angle is analysed. Particular attention is given to the case of complete wetting, that is contact angle equal to zero. Numerical results yield quantitative agreement with the theoretical Washburn law, provided that the correct ratio of the dynamic viscosities between the two fluids is used. Finally, the presence of precursor films is experienced and it is shown that these films advance in time with a square-root law but with a different prefactor with respect to the bulk interface.

13 pages, 8 figures, accepted for publication on The European journal of physics E

References in corpus (4)

• Mesoscopic modeling of a two-phase flow in the presence of boundaries: the Contact Angle
• Capillary Rise in Nanopores: Molecular Dynamics Evidence for the Lucas-Washburn Equation
• Modelling droplets on superhydrophobic surfaces: equilibrium states and transitions
• Lattice Boltzmann simulations of apparent slip in hydrophobic microchannels