I have meshed adiacents fluid and solid regions, separates by wall and wall-shadow boundary zones. Where must I specify the solid surface's emissivity? I have seen that there is an "internal emissivity" coefficient" under wall and wall-shadow boundary panel; there is also a "absorption coeffcient" under solid materials panel, but I don't know if these coefficients are these that I'm finding. Thanks

I am also puzzled by these two coeffcient ...but they have different unit. At present,I think absorption coefficent can be use as semi-transparent material .and set a series of coefficent for non-gray material. One of these coefficent should be his emissivity at his body temperature. those is my opinion .you are wellcome to discuss about it.

Thanks for your response. I have read the discussion that you can find at: http://www.cfd-online.com/Forum/flue....cgi/read/3476, and I think that suggested strategy should be correct. Solid region doesn't take part in radiation because it's its boundary surfaces that absorbs the radiation emitted by C02 and H20 (methane-air combustion case). Radiation heat is transferred, by conduction, across the solid. In this moment I'm trying these strategy and I 'll soon expose the results of simulation. Best regards