Molecular Dynamics Simulation of Non-Fourier Heat Conduction

Unsteady heat conduction is known to deviate significantly from Fourier’s law when the system time and length scales are within certain temporal and spatial windows of relaxation. Classical molecular dynamics simulations were used to investigate unsteady heat conduction in argon thin films with a sudden temperature increase at one surface to study the non-Fourier heat conduction effects in argon thin films. The studies were conducted with both pure argon films and films with vacancy defects. The temperature profiles in the argon films showed the wave nature of heat propagation. Comparisons of the MD temperature profiles with the temperature profiles from Fourier’s law conduction show that Fourier’s law is not able to predict the temperature development with the time. Different film thicknesses were also studied to illustrate the variation of the time needed for the films to reach steady-state temperature profiles, which means that the relaxation time varies with film thickness.