Molecular dynamics study of the nanoscale boiling heat transfer process on nanostructured surfaces

In this study, the effects of nanostructures on nanoscale water boiling heat transfer are investigated using nonequilibrium molecular dynamics simulations. The nanostructured substrates show great superiority over the smooth surface. The bubble nucleation time is advanced and the heat transfer efficiency is enhanced on structured surfaces. Besides, the heat transfer enhancement differs on surfaces with different nanostructures with the same nanostructure volume. Through calculation, it is found that the solid-liquid interfacial area varies with the surface structure configuration and the square nanogroove case which achieves the best heat transfer performance among the nanostructured systems has the largest solid-liquid contact area. To prove the hypothesis that the heat transfer efficiency increases with the interfacial surface area, a solid-liquid-solid system is developed to measure the interfacial thermal resistance between the different solid surfaces and water molecules. The interaction energy per unit area is also calculated to explain the heat transfer variations. Results show that with the increment of surface area which adsorbs more water molecules at the interface could increase the interaction energy per unit area, thereby decreasing the interfacial thermal resistance. The results in this study could provide some insight into the nanostructure design to enhance the heat transfer involving boiling.