[Meph]

Hello, I am working on an electronic free cooling problem (with air). For the first experience, my model is composed of a microprocessor on a PCB in a completely hermetic box (with 2 air spaces) with an exterior air (modeling by a 0.2m ray sphere).
Conditions:
-Boussinesq approximation with an air at 318.15K (exterior and interior) in Z direction
-Power dissipation of processor: 1W.


Visualization:





I have some problem on my model for determine the connections between solid and fluid. For example when I determine a connection between the exterior air and the box (corpse to corpse), when I open fluent, the box is set automatically in fluid (but it was set in solid before). I try to do some connections between solid and fluid with only corpse and face connection but I have no thermal dissipation in the fluid when I solve it.
Example of connection:















So my question is : how can I do properly the different connections to have a dissipation in the air (interior & exterior) ?



Sorry for my bad English, I hope it was understanding.