The study of nanoscale boiling on hierarchical nanostructured surfaces using molecular dynamics simulation

Hierarchical nanostructured surfaces demonstrate significant improvements in boiling heat transfer, making them particularly appealing in thermal energy applications. This study utilizes molecular dynamics simulations to investigate how the vertical spacing and shape of nanobumps impact boiling heat transfer processes over hierarchical nanostructured surfaces. The findings show a notable influence of nanobump shape and the liquid sectional-area beneath them on heat transfer performance. Increasing the vertical spacing of nanobumps is associated with a rise in argon temperature during vapor film formation. Then, the study reveals a reduction in interfacial thermal resistance with increasing vertical spacing of nanobumps and solid-liquid interfacial area of different nanobump shapes. Bubble inception is examined through the analysis of kinetic energy, potential energy, and total energy of atoms, revealing a two-stage phase-change process. The nanobump shape significantly affects liquid cluster detachment time. The surface featuring rectangular nanobumps exhibit larger solid-liquid interfacial area and demonstrate higher evaporation and heat transfer rates compared to surfaces with different nanobump shapes. These findings contribute to a comprehensive understanding of the complex boiling heat transfer at nanoscale on hierarchical nanostructured surfaces. © 2024 Elsevier Ltd.