Static and dynamic behavior of water droplets on the heterogeneous platinum surface

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.In this study, the static and dynamic behaviors of water droplets on heterogeneous surfaces were investigated using molecular dynamics simulations. The surface consisted of the flat plate and pillar structures. The pillar was designed with two heights and three characteristic energies. The simulations were conducted in two steps. In the first step, the water droplet reached the static equilibrium state as a sphere or hemisphere. The static behaviors of the water droplets were in the Wenzel or the Cassie-Baxter state. In the next step, the five forces applied to the water droplets. The dynamic behaviors of the water droplets could be classified into three groups. And the effects of the pillar characteristic energy and the magnitude of the applied force on the behaviors were discussed using the contact angle hysteresis. It was found that a weak pillar characteristic energy had a larger effect on the short pillar height while a stronger pillar characteristic energy had a greater effect on the high pillar height.