TRANSPORT-PROPERTIES OF HIGH-TEMPERATURE AIR COMPONENTS - A REVIEW

The methods for the calculation of the transport properties of high te mperature gases are reviewed from the points of view of both kinetic t heory and transport cross sections. Particular emphasis is given to th e poor convergence of the Chapman-Enskog method for calculating the th ermal conductivity of free electrons and of the possible sources of er rors when applying well known simplified formulae for calculating the translational thermal conductivity of heavy components and the viscosi ty of partially ionized gases. The transport cross sections (collision integrals) of high temperature air components are then discussed by c omparing old and new calculations particularly emphasizing atom-atom, atom-molecule and atom-ion interactions. Special consideration is dedi cated to the knowledge of transport cross sections of electronically e xcited states. The role of inelastic processes in affecting the transp ort cross sections is also briefly discussed. Finally the possibility to extend the results to non equilibrium situations is analysed.