Understanding of Thermal Conductance of Thin Gas Layers

Abstract

We studied heat conductions in a thin gas layer at micro- and nanoscales between two straight walls by atomistic modeling. Since the Knudsen number is high while the gas may be not really rarefied, we use the generalized Enskog-Monte-Carlo method (GEMC) for simulations. The thermal conductivity of thin gas layer is reduced significantly with the decreased thickness of gas layer. We examined a few possible causes including the rarefied gas effect and the thermal inertia effect. Our careful simulations indicate that the temperature jump on wall surfaces and the properties changing significantly by the confined space are two dominating factors to the thermal conductivity reduction of thin gas layers.