Additional information about new radiation post-processing features in Fluent 6.1 for semi-transparent thin walls
In Fluent 6.1 itsurface tension is now possible to post process transmitted, reflected and absorbed components of radiation at semi-transparent walls. These quantities are described in Section 27.4 (Alphabetical listing of field functions and their definitions) as follows
Absorbed radiation flux (band-n): "(in the Wall Fluxes ... category) is the amount of radiative heat flux absorbed by a semi-transparent wall for a particular band of radiation. Its unit is heat-flux"
Reflected radiation flux (band-n): " "(in the Wall Fluxes ... category) is the amount of radiative heat flux reflected by a semi-transparent wall for a particular band of radiation. Its unit is heat-flux"
Transmitted radiation flux (band-n):"(in the Wall Fluxes ... category) is the amount of radiative heat flux transmitted by a semi-transparent wall for a particular band of radiation. Its unit is heat-flux"
Some additional information about these quantities will help users understand how to take advantage of the new reporting features.
To obtain the net transmitted (or absorbed, or reflected) radiation flux in a given band at a semi-transparent thin wall, open the Surface Integrals panel (Report > Surface Integrals ...), select Integral under Report Type, Select Wall Fluxes under Field Variable, and then select Transmitted Radiation Flux (Band-n) under Wall Fluxes. Pick the surface or surfaces of interest and compute the integral.
The following information will help to interpret the results obtained this way
1. In the case of a semi-transparent thin wall, all results are reported at the inner surface of the wall, i.e. the surface that "touches" the computational domain.
2. The transmitted component is the value transmitted through the inner surface minus the absorbed component. The transmitted component is positive if it is leaving the computational domain.
3. The reflection will always be into the domain, so its value is positive.
4. External irradiation specified in the wall boundary conditions panel is not included in the reporting of the transmitted radiation flux from the surface integrals panel. The Flux Reports panel must be used to get the net radiation transfer rate through the semi-transparent thin wall.