AN INVESTIGATION OF RADIANT HEAT TRANSFER IN ABSORBING, EMITTING AND SCATTERING MEDIA

This is a study designed to examine the effect of anisotropic scattering on radiant heat transfer. The equation of transfer for a scattering, absorbing, and emitting medium is simplified by restricting the analysis to axially symmetric, plane parallel geometry. The scattering media are assumed composed of spherical particles of uniform diameter and complex refractive index. The scattering functions are taken from the literature and are the result of application of the Mie theory of electromagnetic scattering. The following problem are considered 1. Radiant heat transfer between a diffuse plane wall and an isothermal, scattering, absorbing, and emitting media of infinite extent. 2. Radiant heat transfer between two diffusely reflecting and emitting plane walls and an isothermal separating medium which scatters, absorbs and emits radiant energy. 3. Radiant heat transfer between two plane walls separated by an absorbing, emitting, and scattering medium in radiative equilibrium. 4. Radiant beat transfer to a diffuse surface bounding one side of an absorbing and scattering medium of finite optical thickness with a uniform parallel flux incident in a normal direction on the free surface of the medium. Results are presented for scattering by spheres composed of material having refractive indices of 1.25 - l.25i and 2.00 - 0.60i, corresponding roughly to iron and carbon respectively, and the case of isotropic scattering. The results include the effect of variations of surface reflectivity, optical spacing, and particle size to wave length ratio.