Lattice Boltzmann Simulations of Bubble Dynamics in Microchannels

The moving contact line problem of liquid-vapor interfaces on solid surfaces was studied using a mean-field free-energy lattice Boltzmann method recently proposed [Zhang et al., Phys. Rev. E, 69, 032602, 2004]. We have examined the static and dynamic interfacial behaviors by means of the bubble and capillary wave tests and found that both the Laplace equation of capillarity and the dispersion relation were satisfied. Dynamic contact angles followed the general trend of contact line velocity observed experimentally and can be described by Blake's theory. The velocity fields near the interface were also obtained and are in good agreement with fluid mechanics and molecular dynamics studies. Our simulations demonstrated that incorporating interfacial effects into the lattice Boltzmann model can be a valuable and powerful alternative in interfacial studies.