Statistical physics approach to heat transfer in gases

In view of the difficulty encountered in extending the electrical analogy approach to study axial heat transfer in a cylindrical column of rarefied gas, a statistical physics approach is proposed for evaluating the thermal conductivity of a gas in terms of the probability for collision free travel of a gas molecule in the gaseous column. The resulting expression for thermal conductance of a gas is found to be more realistic than some existing interpolation formulas, as it uniquely defines the criterion for rarefaction. Moreover, acoustic mode of heat transport can be readily incorporated to understand anomalous heat transfer during heat pulse propagation in gaseous columns. (C) 1996 American Institute of Physics.