Influence of substrate properties on the apparent emittance of an isothermal isotropically scattering medium
Abstract
The apparent directional and hemispherical emittances of an isothermal, isotropically scattering, emitting, and absorbing medium that is bounded by a diffusely emitting and reflecting substrate has been investigated. The exponential kernel approximation is used to develop a closed-form algebraic expression which describes the apparent directional and hemispherical emittances as a function of the optical thickness, substrate reflectance and emittance, and scattering albedo of the medium. The approximation also provides a closed-form solution for the intensity and flux distribution within the medium. Comparison, when possible, with exact solutions indicates very good agreement.
- Publication:
-
ASME Journal of Heat Transfer
- Pub Date:
- May 1977
- Bibcode:
- 1977ATJHT..99..208A
- Keywords:
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- Emittance;
- Isothermal Processes;
- Isotropic Media;
- Substrates;
- Thermal Radiation;
- Approximation;
- Boundary Value Problems;
- Density Distribution;
- Diffuse Radiation;
- Heat Transfer;
- Kernel Functions;
- Optical Thickness;
- Reflectance;
- Remote Sensors;
- Scattering;
- Physics (General)