[Светлана]

I'm interested in modelling radiative heat transfer in a single-phase mixture of air and water vapor. With DOM model enabled, the absorption coefficient of water vapor can be modelled using the WSGGM model. How does Fluent support this?

I have tried enabling 'Species Transport' and defining a new mixture, in whose properties the absorption coefficient is set to 'wsggm-domain-based'; however, with such setup, the absorption coefficients of the parts, such as 'air' or 'water-vapor', are absent in the material properties dialog. Adding co2 to the mixture does not change this.

Manual reference: link (at wwwafs.portici.enea.it).

Any advice would be appreciated.

[alainislas]

WSGGM is used mainly for combustion applications in which combustion products (CO2 and H2O) are strong selective and absorbers of radiant energy. The way the WSGGM is meant to work needs the two gases, for which the molar ratio MR = XH2O/XCO2 is probably the most important parameter, because both the banded absorption coefficients and temperature-dependent polynomial cofficients work only for specific MR's. There are many papers out there that present WSGGM correlations for dry (MR < 1.0) and wet (MR>1.0) conditions. However, in Fluent I believe the standard MR is assumed 1.0 or 2.0.


If your mixture contains only H2O, then you can better refer to classic Incropera's heat transfer textbook and calculate the absorption coeffiient based on emissivity charts