Modeling and simulation of the fluid-solid interaction in wetting

In this work, a lattice-Boltzmann method based on field mediators is proposed for the simulation of wetting in a liquid-vapor system. The method includes the effect of long-range interactions between the particles and solid walls, and is implemented together with a liquid-vapor model which is known from the literature. The results that were obtained in the simulations show that the contact angle is strongly dependent on the long-range interactions. The initial formation of a film ahead of the macroscopic bulk liquid is observed below a specific contact angle. When rough solid surfaces were used, the simulations exhibit the contact angle hysteresis. The spreading dynamics on solid surfaces was studied and showed a considerable discrepancy from the expected value, which was attributed to the high resolution of the numerical simulations. It is shown that the initial conditions have a strong influence on the first steps of the droplet spreading, but they become negligible at long times.