Non-equilibrium molecular dynamics study of nanoscale thermal contact resistance

Interfaces play an important role in microscale and nanoscale heat transfer processes with molecular dynamics ( MD) simulations often used to study these interfacial phenomena. In this study, two models were used to simulate thermal conduction across micro contact points and the thermal contact resistance using non- equilibrium molecular dynamics simulations with consideration of the near field radiation. When the ratio of the length of the micro contact to the length of the conduction region is less than 0.125, the influence of the near field radiation should be considered; but when the ratio is larger than 0.2, it can be neglected. When the computational domain sizes are 8.50 x 10.62 x 8.50 nm and 10.62 x 10.62 x 10.62 nm, the MD results show that the thermal contact resistance exponentially increases with decreasing area of the micro contact point and increases with increasing micro contact layer thickness. The MD thermal contact resistances in nanoscale are much larger than that of the classical thermal analysis since the material thermal conductivity reduction is ignored in the classical model. The results also show that material defects increase the thermal resistance.