Reports: G9
48674-G9 Effects of Air Pressure and Wettability on Drop Impact on Dry Surfaces
This proposal aims at modeling the effects of air pressure on drop impact on dry surfaces with difference wetting characteristics and investigating drop dynamics after impact under different conditions. During the first year, we focused on the effects of wettability on drop impaction process and developed proper boundary conditions for our multi-phase lattice Boltzmann method (LBM). We proposed three types of polynomial boundary conditions (linear, quadratic, and cubic) based on the wall free energy approach for the accurate prediction of the contact angle and density distribution close to a solid surface (Liu and Lee, in press). When the fluids have large property contrast and the impact of the gas phase on wetting is small (e.g., water-air system), the higher-order boundary conditions ignore the interplay between solid and gas-phase so that the negative gas wall density can be avoided resulting in more stable simulation results. We have studied micron-sized drop impact on dry surfaces with different wetting properties (Lee and Lin, in review) and fundamental flow physics in bubble rising problems (Amaya-Bower and Lee, in review).
