A useful integral function and its application in thermal radiation calculations
Abstract
In applying the Planck formula for computing the energy radiated from an isothermal source, the emissivity of the source must be found. This emissivity is expressed in terms of its spectral emissivity. This spectral emissivity of an isothermal volume with a given optical length containing radiating gases and/or soot, is computed through a relation (Sparrow and Cess, 1978) that contains the optical length and the spectral volume absorption coefficient. An exact solution is then offered to the equation that results from introducing the equation for the spectral emissivity into the equation for the emissivity. The function obtained is shown to be useful in computing the spectral emissivity of an isothermal volume containing either soot or gaseous species, or both. Examples are presented.
 Publication:

International Communications in Heat and Mass Transfer
 Pub Date:
 August 1983
 Bibcode:
 1983ICHMT..10..329C
 Keywords:

 Entire Functions;
 Spectral Emission;
 Thermal Radiation;
 Emissivity;
 Radiative Heat Transfer;
 Fluid Mechanics and Heat Transfer