Molecular dynamics simulation on effects of nanostructure on interfacial thermal resistance during condensation

Abstract

Condensation of fluid molecules on a solid surface with and without a structure at the nanometer scale was simulated by means of the classical molecular dynamics simulations. We investigated effects of the nanostructures and the wettability, on the condensation process and an interfacial thermal resistance on whole surfaces and segments of the surface with the nanostructure. In our calculation system, we employed the fluid system of argon confined between two parallel solid walls, where a cuboid nanostructure was attached to the solid bottom wall. All intermolecular potential functions were the 12-6 Lennard-Jones form. We simulated hydrophobic and hydrophilic conditions by changing the intermolecular strength between the fluid molecules and the solid walls. Our results showed that the droplets tended to be formed at the base of the nanostructure and a droplet formed at the top of the nanostructure, regardless of the interaction strength between the fluid molecules and the solid walls. In addition, the wettability influenced on the contribution of each segment of the nanostructure on heat transfer during condensation. Local interfacial thermal resistance at the top and base of the nanostructure was relatively smaller than those at other segments of the nanostructure at an early stage of the condensation in the case of hydrophobic surface.

Keywords

• condensation
• molecular dynamics
• nanostructure
• interfacial thermal resistance
• heat flux
• nucleation