Lattice Boltzmann Study of the Water Droplet on a Surface Corrugated with Nanopillars

摘要

Using the lattice Boltzmann method, we simulated a water droplet on a surface covered with rectangular or parabolic pillars. With increasing spacing between the pillars, the transition from the Cassie to Wenzel states of the droplet was observed. The critical spacing at which the transition occurs and the contact angle of droplet were compared with those obtained from the macroscopic theories of Cassie and Wenzel. The present simulation revealed intermediate states where the droplet was partially impaled by the pillars. Even in the Cassie state, the droplet significantly penetrated down in the gap between the parabolic pillars.