A Possible Role of Nanostructured Ridges on Boiling Heat Transfer Enhancement

Evaporation of a nanoscale meniscus on a nanostructured heater surface is simulated using molecular dynamics. The nanostructures, evenly spaced on the surface, are ridges with a width and height of 0.55 nm and 0.96 nm, respectively. The simulation results show that the film breaks during the early stages of evaporation due to the presence of nanostructures and no nonevaporating film forms (unlike a previous simulation performed in the absence of nanostructures where nonevaporating film forms on the smooth surface). High heat transfer and evaporation rates are obtained. We conclude that heat transfer rates can be significantly increased during bubble nucleation and growth by the presence of nanostructure ridges on the surface as it can break the formation of nonevaporating film. This causes additional chaos and allows the surrounding cooler liquid to come in contact with the surface providing heat transfer enhancements.