G. Göbel, J. Kuhn, and J. Fricke
Radiative Heat Transfer in Thermal Powder Insulations
10. International Heat Transfer Conference, Brighton, UK, 14.-18.Aug. 1994
Abstract:
Radiative transfer in loose powder beds can be described by a series of
single scattering and absorption processes. When solving the equation of
radiative transfer, the anisotropy of the single scattering process is taken
into account by employing scaling laws which invole the factor of asymmetry
g. This
quantity can be obtained by performing directional--hemispherical and
directional--directional measurements. g can also be determined from the
angular distribution of the single scattering process, using a polar
nephelometer.
The scattering properties of the powders can be correlated with the
effective extinction of the powder and thus with the radiative conductivity.
Measurements on TiO2 and diatomite powders show good agreement
in the values of g derived with the above methods. Mie calculations
support the experimental results.
