HEAT-TRANSFER IN RAREFIED-GAS AT A GAS-SOLID INTERFACE

Modified expressions for the heat-transfer fluxes at the interface of a solid surface and a gas are given different Knudsen-number regimes. These expressions for diatomic gases contain both a gas-reflection and a thermal accommodation coefficient. Parallel-plate, coaxial-cylindri cal and concentric-spherical surfaces are considered. A general expres sion for the thermal accommodation coefficient is based on experimenta l data. Sample numerical calculations of heat flux in different heat-t ransfer regimes are presented in terms of the reciprocal Knudsen numbe r.