ANSYS Convection Between 2 Solid Bodies

[tmlw66]

Hi, I'm new to the forum and new to Ansys! I'm using the Steady State Thermal feature within Ansys 15.0 Mechanical. I'm in the process of running some analysis for my senior design project which is a solar powered cooler and need some help. The goal is to take the interior temperature of the cooler and the exterior ambient temperature and find the heat flux through the cooler walls.

The cooler structure consists of:
-interior aluminum wall
-5 mm thick air gap
-polyurethane foam insulation
-exterior plastic cooler shell

I'm starting off simple and am only focusing on/modeled one wall of the cooler. Essentially an infinite length wall problem. I have all 4 of the sections modeled (including the air) in an assembly that I already imported and meshed. I inputted their material properties. I applied a convection boundary condition at 35F to the interior aluminum wall and a convection boundary condition at 100F to exterior plastic wall. I left the top, bottom, and sides of the walls perfectly insulated.

I can run the solution now but I think its only considering conduction through the air...is that correct? What I need help on is how to add convection from the polyurethane to the aluminum through the 5mm air gap. Is it correct to have a solid model for the air? Do I need to be using Fluent rather than steady state thermal? Any help would be appreciated.

Thanks in advance!

 

[corus]

Generally with small air gaps the heat transfer is via radiation. Conduction through the air is negligible, and for such a small gap there's unlikely to be any convection.