Droplets on Micro Structured or Patterned Surfaces With Different Roughness Parameters

Surface wetting properties play important roles in boiling and condensation. In this paper, the wetting behaviours of a single droplet on micro structured or patterned surfaces with different roughness parameters are investigated theoretically and numerically. A theoretical model is proposed to study wetting transitions. Comparison between results obtained by theoretical analysis with those of experiment indicates that the proposed model can give a better prediction of wetting transition. In addition, a numerical simulation based on lattice Boltzmann method (LBM) is performed to study surface wetting properties and also the evolution of droplet shapes, dynamic contact angle and corresponding velocity fields. In the simulation, the droplet size is comparable with the scale of micro posts on the surface.