Effect of liquid bulk density on thermal resistance at a liquid-solid interface

Thermal boundary resistance (TBR) at a liquid-solid interface that consists of simple Lennard-Jones atoms is studied by molecular dynamics simulation. A liquid layer is confined narrowly between flat solid surfaces in the simulation, and the mean density of the confined liquid is varied. A thermal gradient is imposed in the system by applying constant heat flux, and TBR is calculated using the temperature profile results. TBR is highly dependent on the bulk density of liquid when the liquid does not wet well with the solid. The bulk density gives a dominant influence over the liquid-side structure at the interface, which determines TBR in part. In the system of fluid on a high energy solid surface, the wetting system, even when the interfacial structure shows a marked dependence on the density, TBR depends less on the bulk fluid density