Reverse Nonequilibrium Molecular Dynamics Simulation for Thermal Conductivity of Gallium-Based Liquid Metal

Abstract

Liquid metal (LM) has attracted much attention in advanced thermal management due to its superior thermal conductivity. The traditional research method of LM thermal conductivity is mainly based on experimental measurement at the macroscale. It is well known that thermal conduction is attributed to the thermal motion of molecules and atoms. It is valuable to study the thermal conductivity of LM in conjunction with atomic thermal motion at the microscale. In this work, the reverse nonequilibrium molecular dynamics (RNEMD) method is proposed to study the variation pattern and influencing factors of gallium-based LM thermal conductivity. The three-dimensional physical model of crystal lattice structure was developed. The thermal motion trajectories of atoms at the microscale were observed and investigated. The thermal conductivity was calculated by the RNEMD method. The effect of temperature and components on the thermal conductivity of gallium-based LM was systematically analyzed. The results show that the thermal conductivity of gallium-based LM increases linearly with temperature, which is consistence with the trend in the intensity of atomic thermal motion. Furthermore, the thermal conductivity of Ga42.25In35.5Sn22.25 is significantly higher than that of Ga67In20.5Sn12.5 at high temperatures, which might be attributed to the higher proportion of indium and tin in the alloy. However, the increase in the composition of tin inhibits the atomic thermal motion at low temperatures, thus weakening the heat transfer properties of the alloy.