Numerical Prediction of Contact Line Dynamics on Super-Hydrophobic Surfaces

The current study numerically investigates the motion of droplets on a surface with a micro cavity using the Volume of Fluid (VOF) technique. The simulation is a precursor to droplet motion on super-hydrophobic surfaces which is the focus of surface engineering research in recent times. The advancing and receding contact angles are tracked as a droplet moves on a single cavity which can be seen as the space between two posts of a typical engineered super-hydrophobic surface. Stick-jump-slip behavior can be seen during the advancing motion of the drop and the reverse is seen during the receding motion. The contact angle evolution is studied for three different post geometries and it is concluded that wider post spacing leads to smaller dynamic contact angles. This study is important from the point of prediction of dynamic contact angles computationally on super-hydrophobic surfaces.