Numerical simulation of advancing interface in a micro heterogeneous channel by the lattice Boltzmann method

The lattice Boltzmann method for multicomponent immiscible fluid is applied to the simulations of wetting dynamics in micro channels. The wetting condition is introduced with the wetting potential which gives free energy on the wetting wall. To confirm the validity of the model, the static contact angle of a droplet onto a wetting wall is calculated and compared with Young's equation. Then, the flow behavior near the interface in hydrophilic and hydrophobic channels is investigated and compared to the experimental results. Finally, the method is applied to the flow in micro channels with heterogeneous and hydrophilic wetting walls. It is found that the interface is advanced only by the capillary force and that different interfacial disorders appear due to the heterogeneousness of the wetting potential of the wall.