Boiling heat transfer of nanofluids on the graphene membrane: A molecular dynamics simulation

The molecular dynamics method was used to study the boiling heat transfer of the base fluid (consisting only of water molecules) and nanofluid film on the graphene membrane. The nanofluid consists of water molecules and Cu nanoparticles of three sizes (0.8 nm, 1.2 nm, and 2 nm). Compared with the boiling heat transfer of the base fluid on the graphene membrane at high superheat, the influence of nanofluids with different particle sizes on boiling heat transfer was studied. The effects of the particle size, the water temperature at the radial distance of the particle surface, the molecular mass density distribution, the evaporation rate, and the heat flux on the boiling are analyzed. The heat transfer at the interface between nanoparticles and graphene mainly relies on phonons. The results show that the nanoparticles act as an indirect heat source to heat the surrounding water molecules and strengthen the boiling heat transfer at the solid-liquid interface, and the thermal conductivity at the interface increases with the increase of particle size. The atomic vibration frequencies between the graphene membrane and nanoparticles are well coupled in the low-frequency region, which enhances the boiling heat transfer.