Learning Forum

[Juhani Manninen]

Hi

I am trying to learn how to use Ansys Fluent for steady state 2D thermal analysis. I am attempting to simulate a situation where an electrical conductor generates heat, and the conductor is surrounded by an air-filled fluid region, which in turn is enclosed by a solid material (wood). It seems that natural convection is not working in the fluid region, and the heat does not appear to transfer from the fluid to the wood. Could someone advise what might be wrong? I have managed to simulate a similar situation with only an aluminum core surrounded by air, i.e., a solid-fluid setup.

 

Here is some details:

[Rob]

Why do you need interface zones? If they're not set correctly it'll not help. Then check air density. 

[Juhani Manninen]

Interface zones are generated automatically, I can't say if they are necessary. I believe the air density is correct since it works in the solid-fluid case that I previously managed to get working. Attached is an image of this earlier solid-fluid simulation. It is slightly larger in dimensions, but otherwise, it operates on the same principle. In that case, natural convection works, and the residuals converge. In the solid-fluid-solid situation, there is probably some boundary condition issue, but I can't pinpoint what it is.

 

Here is results of that solid-fluid case.

[Rob]

In a sealed domain you need ideal gas. Incompressible ideal gas would be the correct choice in an open domain. 

Solid-fluid nonconformals are a little special and I'd avoid when learning to use the software. Read up on share-topology.