solid surface's emissivity
 

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