Effect of nanostructures on rapid boiling of water films: a comparative study by molecular dynamics simulation

Abstract

Nanostructures, such as post, sphere, cone, and cuboid, can drastically enhance the rapid boiling heat transfer from a solid plate to adjacent liquid molecules. In this work, we demonstrate the effect of nanostructures on the rapid boiling of water films by molecular dynamics simulation. The comparison between cubic and T-shaped nanostructures which are based on a copper plate is implemented. Rate of temperature rise and departure velocity from the structure for water boiling on T-shaped nanostructure have the greatest values followed by cubic nanostructure and flat plate. The densities of water films above these nanostructures are higher than that above flat plate. Departure velocity and restrictions on the movement of water molecules due to the structure beneath the cuboids can affect the heat transfer coefficient between water film and copper plate with T-shaped nanostructure. The heat flux vs. the time in the non-equilibrium phase change stage is given. With the variation of heat flux vs. time being similar, cubic and T-shaped nanostructures show greater heat fluxes than that of the plate when the vapor films appear. It is strongly recommended to use the new nanostructure for rapid boiling, and further study on the mechanisms of liquid molecules behaviors in nanostructures with various structural parameters is suggested for process intensification.