Thermodynamic quantities of the heat-conduction steady-states of low-density gases in circular geometries

Abstract: A low-density gas is considered between two coaxial cylinders or two concentric spheres maintained at different temperatures. For the weakly nonequilibrium case, it is found out how the form of the vessel influences on thermodynamic quantities – pressure and entropy. The corresponding expressions are obtained as expansions in the temperature gradients up to the 4-th order. The result for the entropy is shown to be compatible with the second law of thermodynamics. The expansion for the average radial distance describes the internal mass displacement induced by the temperature nonuniformity.