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.
