Geometry issue in THERM 7.8.80

[Juan Muñoz]

Hello!

I am analyzing the thermal transmittance of an AHU profile, specifically a corner profile and a central profile (omega), both with thermal break.

The goal is to add a panel to create something similar to attached.

The profiles are made of anodized aluminum, and the internal cavities have been defined as Frame Cavity. The thermal break components are made of nylon.

I started from a DXF file containing the cross-sections of both the corner profile and the omega profile.

However, direct import from AutoCAD was not successful, as non-closed polygons appeared.
For this reason, I redrew the polygons following the DXF geometry.

Once the DXF is loaded, I am unable to complete the meshing and calculation in either case.
I have tried splitting the polygons adjacent to the internal cavities and also reducing the level of detail for both the corner and the central profiles.

Visually, there do not seem to be any overlapping polygons, but when attempting to run the calculation, a message appears indicating that the calculation cannot be completed due to incorrect geometry.

If possible, I would greatly appreciate any help in correcting these geometries so that they are valid for calculation.

I am attaching the THM files in case they are useful.

Thank you very much in advance!

Best regards.

Juan Ramon.-

[Robin Mitchell]

What version of THERM are you using? 

Robin

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Robin Mitchell

Windows & Envelope Materials Group
Lawrence Berkeley National Laboratory

[Robin Mitchell]

You have a void in the middle of your model which THERM does not allow. Fill it with a frame cavity material

[Juan Ramón Muñoz]

Hi Robin!

THERM Version 7.8.80.0 

05/08/25.

Many thanks for your assistance!

  I filled the inner area by assigning it material, but I think some geometry isn’t correct at certain points.  

 

No bad points appear. However, when I run the calculation, I get this message:  

Juan.-

[Robin Mitchell]

Can you provide your new THERM file? 

[Juan Ramón Muñoz]

Of course. See attached.

[Robin Mitchell]

i was able to get the file to simulate, but because there is a thermal connection from outside to inside via the aluminum elements, there is not much temperature difference between the inside and outside. 

I just used standard boundary conditions in the program for outside and inside surfaces, so you will want to make your own that are appropriate for what you are trying to model. 

I have attached my file.

Here are the fixes I made. 

When I tried to generate the boundary conditions, the program identified this area where there was still a void

[Juan Ramón Muñoz]

Thank you very much, Robin!
I agree with your observations.
This is exactly what I needed, although I still need to close the remaining gaps.

Your expert help has been very valuable. I will review the model accordingly and let you know if I have any further questions.


Kind regards!
Juan.-