Study of boiling heat transfer on concave hemispherical nanostructure surface with MD simulation

The cooling process on superheated surface at nanoscale is significantly distinct from that at macroscale or microscale. In this work, the boiling phenomena of liquid argon thin film on concave hemispherical nanostructure surfaces have been investigated with molecular dynamics (MD) simulation. For each surface, the substrate temperature was progressively increased and the non-equilibrium MD simulation was carried out to record the variation of atomic motion trajectories, number of vapor and liquid atoms, kinetic energy and internal energy with time. By comparing the obtained predictions of boiling heat transfer on different nanostructure configurations (concave hemispherical, flat and convex hemispherical), it shows that the nanostructure on solid wall can enhance the heat transfer process and concave hemispherical nanostructure presents a better thermal energy transfer capacity at the low substrate temperature. Moreover, the surfaces with different wettable concave nanostructure were considered to study the wettability effect on boiling heat transfer characteristics. The hydrophilic concave hemispherical nanostructure surface has a better heat transfer performance and the hydrophobic concave hemispherical surface has a better tolerance for heat transfer deterioration. The findings in this work prove the capability of enhancement technique for boiling heat transfer processes using concave nanostructure surface, which can be applied in future advanced cooling solutions. (C) 2019 Elsevier Ltd. All rights reserved.