[kamakura117]

I have a question with regard to boundary conditions using radiative heat transfer. I have a gas volume sandwiched between two solid surfaces, where both interfaces are then set as a contact interface. The surface for one of the solids has an emissivity of .98 and is at 1273 K and the other has an emissivity of .11 (reflectivity .89). The gas interfaces then should, I would assume, be set to have a transmissivity of 1.0, since I’m assume there is no radiative interaction with the gas. However, I do not have any radiation heat transfer in this case. I must set the emissivity to some absolute value in order to acquire some heat transfer, which I think, is incorrect since this then assumes that the gas heats up to then generate radiation to transfer to the other surface. How, then, would I get 100% of the radiation from one surface to reach the other? I made sure to set the physics continuum to use S2S radiation and not participating medium, and I set the surface orientation of the gas volume to be inward and the solids to be outward.

If anyone could provide some insight, I would be greatly appreciative.