Mean-field free-energy approach to the lattice Boltzmann method for liquid-vapor and solid-fluid interfaces.

We present a lattice Boltzmann method (LBM) using a mean-field representation of the free energy for fluid systems. This free-energy approach provides more realistic contact angles and fluid density profiles near the vicinity of an impenetrable wall which cannot be easily obtained by other LBM schemes. Our method was tested against various criteria and the results are in good agreement with those from thermodynamics and molecular dynamics considerations. This mean-field approach to LBM can have an important implication on studies where the solid-fluid interactions are crucial to fluidic behaviors.