Molecular-continuum simulation of elevated temperature drag reduction by nanostructure-induced vapor layer

Abstract

Vapor lubrication resulting from liquid evaporation on a heated decorated surface and the consequent reduced friction drag are explored via computational fluid dynamics. Molecular dynamics simulation is performed to analyze the vapor layer generated by various cuboid nanostructures. Simulation results indicate that the surface with an elevated temperature provides excessive temperature that may lead to the easy formation of a thick vapor layer. For a cuboid nanostructure, the results indicate that the nanostructure arrangement enhances evaporation. Such enhancement can be affected not only by the large contact area between liquid and solid but also by the adjacent space surfaces of the nanostructure. This study is relevant because it can provide a feasible optimal design approach for nanostructures that exhibits broad prospect for high-temperature microchannel lubrication systems.