Julia Yeomans OBE FRS

Abstract:

We present a lattice Boltzmann model to describe the spreading of droplets on topologically patterned substrates. We apply it to model superhydrophobic behaviour on surfaces covered by an array of micron-scale posts. We find that the patterning results in a substantial increase in contact angle, from 110degrees to 156degrees.

Abstract:

The applicability of a mesoscale modeling approach to the problem of contact line motion in one and two phase fluids was investigated. The thermodynamics boundary conditions were implemented, which allows to fix the static contact angle in the simulations. It was found that the contact line was overcome by evaporation or condensation near the contact line which was driven by the curvature of the diffuse interface. An analytic approximation was also derived for the angular position of a sheared interface.

Abstract:

We investigate the applicability of a mesoscale modeling approach, lattice Boltzmann simulations, to the problem of contact line motion in one- and two-component two phase fluids. In this, the second of two papers, we consider binary systems. We show that the contact line singularity is overcome by diffusion which is effective over a length scale L about the contact line and derive a scaling form for the dependence of L on system parameters.

Abstract:

We investigate the applicability of a mesoscale modeling approach, lattice Boltzmann simulations, to the problem of contact line motion in one and two component, two phase fluids. In this, the first of two papers, we consider liquid-gas systems. Careful implementation of the thermodynamic boundary condition allows us to fix the static contact angle in the simulations. We then consider the behavior of a sheared interface. We show that the contact line singularity is overcome by evaporation or condensation near the contact line which is driven by the curvature of the diffuse interface. An analytic approximation is derived for the angular position of a sheared interface.