Molecular dynamics simulation on bubble nucleation and boiling heat transfer of R1336mzz(Z) nanofilm with varying boundary heating rates

Nucleate boiling of low-boiling-point fluids is one of the most efficient heat transfer techniques in electronics cooling. However, it may undergo ultrafast heating in extreme scenarios, leading to distinct heat transfer mechanisms. Since the early stage of nucleation involves quite small time and length scales, the experimental and mesoscopic or macroscopic methods still suffer from limitations. In this study, the aim is to establish a thin liquid film boiling model using molecular dynamics simulation, with R1336mzz(Z) as the working fluid. A three-phase simulation is considered where R1336mzz(Z) film is subjected to non-equilibrium heating from a smooth copper substrate. Depending on boundary heating rates (50–250 K ns⁻¹), nanofilm undertakes distinct phase change phenomena. Meanwhile, the key characteristics like molecule distribution, center of mass, vaporization rate, onset of nucleation and film boiling are discussed to describe the evolution of liquid film. Results suggest that bubble growth has an exponential function in relation to boundary heating rate because higher thermal resistance leads to thermal deterioration at the bottom liquid film. Thus, there is a trade-off between heating rate and heat transfer enhancement. These findings deliver molecular-scale understandings of the nucleation mechanism and boiling heat transfer of low-boiling-point dielectric fluids.