Boundary treatment effects on molecular dynamics simulations of interface thermal resistance

Molecular Dynamics simulations of heat conduction in liquid Argon confined in Silver nano-channels are performed subject to three different thermal conditions. Particularly, different surface temperatures are imposed on Silver domains using a thermostat in all and limited number of solid layers, resulting in heat flux in the liquid domain. Alternatively, energy is injected and extracted from solid layers to create a NVE liquid Argon system, which corresponds to heat flux specification. Imposition of a constant temperature region in the solid domain results in an unphysical temperature jump, indicating the presence of an artificial thermal resistance induced by the thermostat. Thermal resistance analyses for the components of each case are performed to distinguish the artificial and interface thermal resistance effects. Constant wall temperature simulations are shown to exhibit superposition of the artificial and interface thermal resistance values at the liquid/solid interface, while applying thermostat on wall layers sufficiently away from the liquid/solid interface results in consistent predictions of the interface thermal resistance. Injecting and extracting energy from each solid layer eliminates the artificial resistance. However, the method cannot directly specify a desired temperature difference between the two solid domains.