Passive radiation cooling to night sky

All, I have a concept to model the effect of passive radiation cooling to the night sky due to atmospheric transparency to IR radiation. The simulation would model the temperature variation of some geometry over time as the ambient air temperature varies (for night time decreasing linearly to some final value over say 8 hours). The model geometry is pretty simple. A 1x1 meter aluminum plate, depth 3mm. One side is painted black and faces the sky. The reverse side of the plate, is bare aluminum. I’m not sure how to setup the model, the simulation, or not even sure SimScale can simulate this effect. My thought on the geometry is create a very large domain (say 10x scale of the plate) to represent ambient air. The plate geometry is embedded in the ambient air domain. Assign emissivity of 0.9 to black side of the aluminum plate, and 0.4 emissivity (assume some oxidation) for bare aluminum side. Air domain is assigned STP parameters with initial temp1 and final temp2. Time varies 0 to 8hrs. Assume clear night sky. Use SimScal convection with radiation effect.
Is this the right approach?

Hello kwoellert,
thanks for reaching out to us here In the forum.
I think that the general setup is possible.
You can have a look at this article on how to define boundaries for radiation walls.

The only thing I am a bit concerned about is the transient approach because that will require really large time steps. Even a time step of 1 sec will lead to 28.8k time steps. Maybee, you can start with a smaller time period like one hour. Do dial in the mesh and general settings.

Best regards Sebastian