Entropy generation through radiative transfer in participating media: analysis and numerical computation

Thermodynamics' second law analysis is the gateway for optimization in thermal equipments and systems. Through entropy minimization techniques it is possible to increase the efficiency and overall performance of all kinds of thermal systems. This approach is becoming common practice in the analysis and/or design of thermal equipments. However, evaluation of entropy generation due to radiative transfer in participating media seems to be lacking. Since radiation is the dominant mechanism of heat transfer in high-temperature systems, such omission seems quite unjustifiable. Although the subject of entropy production through radiative transfer has been dealt with for quite some time, notably by Max Planck himself, it has not been approached in the perspective of its numerical calculation in a way that is compatible and coherent with the standard heat transfer approach. In the present work, the issue of entropy generation by radiative transfer in participating media is approached from the view-points of its mathematical modeling and numerical calculation using standard radiative heat transfer techniques, namely the discrete ordinates method. Effects from emission, absorption and scattering are isolated and considered independently.