On Grey Absorption Coefficients in Radiative Transfer

摘要

The radiative heat flux and several frequency averaged absorption coefficients were calculated for a plane-parallel radiating gas slab, for a variety of absorption spectra. Both constant temperature and constant temperature gradient are considered. None of the assumptions concerning these coefficients of several recent non-grey models turn out to be verifiable, except at best under more restrictive conditions. With constant temperature, the heat flux is to a good approximation the same function of a single optical depth as in a grey gas. With variable temperature a radiative transfer equation with a common coefficient for both emission and absorption terms becomes meaningless, a separate coefficient should be used for the absorption term. (Author)