A Study on Thermal Resistance over a Solid-Liquid Interface by the Molecular Dynamics Method *

Abstract

Through molecular dynamics simulations, it was demonstrated that a thermal resistance cannot be neglected over a solid-liquid interface when a system size is very small, i.e. the relative importance of thermal resistance of heat conduction is small. A quasi-steady non-equilibrium heat-transfer simulation was performed with the molecular dynamics method. A vapor region was sandwiched between liquid layers, which were in contact with two solid walls. While independently controlling temperatures at ends of walls by the phantom method, the energy flux through the system was accurately calculated. The measured temperature distribution normal to interfaces showed a distinctive jump near the solid-liquid interface, which could be regarded as the thermal resistance over the interface. The thermal resistance was measured for various interaction potential parameters between solid and liquid molecules so that a wide range of wettability could be covered. The thermal resistance was equivalent to 5~20 nm thickness of liquid heat conduction layer, and was strongly dependent on the wettability.