THERMAL RADIATION IN PART1CULATE MEDIA WITH DEPENDENT AND INDEPENDENT SCATTERING

The present work gives an overview of the existing knowledge of radiative heat transfer in particulate media. Special emphasis is given to the proper usage of realistic scattering characteristics of particles. It begins with an introduction of the basic formulation for radiative heat transfer with scattering. This is followed by a discussion on the classification of different scattering environments such as the various single scattering regimes (i.e., Rayleigh. Mie and geometric), single versus multiple scattering, and independent versus dependent scattering. Different numerical models of radiative transfer in independent scattering media are then reviewed and employed for comparison with reliable experimental information. Numerical results for the absorption and scattering coefficients, based on Mie scattering calculations, exhibit excellent agreement with packed-bed transmittance data. For dependent scattering media, numerical schemes for computing scattering efficiencies are described and shown to yield results in good agreement with measurements.