Molecular dynamics simulation of heat and mass transfer in a nano-grooved heat pipe: Focusing on filling ratios’ effect

Managing the heat generated in microprocessors and other similar heat-generating devices requires the design and construction of superconductors with high reliability. For this purpose, heat pipes (HPs) are a very good option. Nano-grooved micro flat plate heat pipes (FPHPs), which are in the group of vapor chambers (VCs), have received attention due to their suitable structure.

In this research, an FPHP with a length of 1050 nm is investigated using molecular dynamics (MD) simulation. The effects of using three metals for walls including platinum (Pt), copper (Cu), and aluminum (Al) as well as three working fluids including argon (Ar), water (H₂O), and ethanol (EtOH) were investigated. Focusing on the filling ratio of the interior space, mass and heat transfer inside the HP has been fully investigated. Evaporation rate, condensation rate, temperature, density, and velocity distribution as well as heat flux have been studied.

The results show that although Ar shows better mass transfer results (due to its monoatomic nature), EtOH has better thermal performance. Among the three metals used, Cu has the best thermal performance. The maximum heat flux is obtained by using Cu and EtOH and is equal to 1819 W/cm². The optimal filling ratio is reported in different states. The maximum mass transfer rate relates to Ar and at FR = 0.3; which equals 32.5%. The highest phase change rate is obtained using platinum and water, which is equal to 74%.