The physics of the heat conduction and viscous dissipation in rarefied gases is analyzed and discussed. A heat transfer model valid for arbitrary Knudsen numbers, defined as the ratio of the molecular mean free path to the characteristic length of channels, is derived by treating the heat transfer behavior in the slip and transition regimes as an intermediate function of continuum heat transfer model and free molecular heat transfer model. Comparison studies reveal that this model not only shows good agreement with the numerical results based on the direct simulation Monte Carlo method, but also has some unique features that can overcome the deficiencies existing in the previous models. Therefore, this model is capable to study the heat transport phenomena in very dilute gas Couette flows through micro/nanochannels more accurately.

• Received 22 July 2008

DOI:https://doi.org/10.1103/PhysRevE.81.011204