[federernadal]

Hi,

I am trying to model airflow over a coil. I would like to see the airflow patterns at varying tilts of the coil.

How do I do this?

[ghorrocks]

This sounds like a basic CFD task. This is well covered by the tutorials provided with your meshing software and CFX.

[federernadal]

Is this a CFD or a Geometry task?

[federernadal]

I guess I wasnt too clear. I am looking to Parametrize the angle that I rotate this coil against the airflow mass exiting.

Just not too sure on how exactly to link them together.

[ghorrocks]

There are plenty of tutorials in ANSYS Workbench which show how to use parameters as well.

[federernadal]

So I have a coil, and I made an enclosure.

I do a Boolean Subtract to subtract the coil out of the box (I preserve bodies though).

I create 2 domains. Porous for the coil and fluid for the air.

BCs on the enclosure walls - 1 mass flow inlet and 1 p=0 outlet

Why am I getting a negative element size error?

Thanks.

[ghorrocks]

FAQ: http://www.cfd-online.com/Wiki/Ansys..._went_wrong.3F

Or if you get this error and you are not doing an FSI simulation then you have a severe problem with your mesh. Use the tools in your meshing software to mesh the domain properly.

[federernadal]

Glenn, thanks - got past that error by adding some mesh controls. But after getting crappy results I am beginning to question my overarching strategy.

Need to go over my plan to simulate a condenser coil with refrigerant running through it (to heat air passing over/through it) using CFX.

I want to model the coil as a rectangular plate - porous domain (actual geometry is wayyy to complex to model). Then, place an enclosure - fluid domain (air).

Have a BC with air inlet on one side face of enclosure using a mass flow rate and leaving through the other side face with avg static pressure of 0.

However, I also want to model heat transfer. When I generate the porous domain, I am not sure how to have it be at a certain temperature so it exchanges heat with the air above it. I want the refrigerant running through the porous domain be at say 140 deg fahrenheit. And the air I will at the inlet face at around 70 deg fahrenheit.

I get all blue lines for velocity and temperature (no heat exchanged) all over (crappy results) - Should I manually place walls on my coil/porous domain? Btw, do wall BCs on porous domains mean fully solid faces or are they still porous?

[federernadal]

Help? Anybody?