Temperature field started diverging

Using SimScale
1

I’m trying to simulate this tutorial but I’m having problems. Thermal Comfort In a Meeting Room | Tutorial | SimScale
This is giving me this temperature error, would anyone know how to resolve it?

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Temperature field started diverging. Please check the mesh quality near the reported location and try refining the mesh. If the problem occured near a boundary, please check the boundary conditions. In case of doubt, please ask for assistance via our support chat. Temperature = 100696 at position: (3.021 m, -5.977 m, 3.286 m).

2

Hi @rparmigiani, thanks for posting on the forum :slight_smile:

Welcome to the SimScale Community :handshake:

There’s a workflow for identifying and solving convergence issues, which can be found in the following knowledge base article:

Most times, it has to do with checking and improving the mesh quality, we also have a great article on that:

In your last Run, it seems the simulation diverged near the velocity inlet:

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There doesn’t seem to be a good transition between the boundary layers and the elements in that region, which might be causing a high volume ratio there - leading to the lack of convergence:

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You could try increasing the number of layers on your refinement and changing the growth rate to a lower value as well:

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The important part is that the last boundary layer cell needs to have a smooth transition with the surface mesh.

Does that help?

Best,
Igor

3

Thank you for the help!! What would be a good layer number to set?

4

Hi @rparmigiani,

That depends a lot on the final cell size. In the documentation for that sort of refinement, you can find the definition of all of those quantities to be inserted, you just have to find one that fits with the cell size after the boundary layer ends.

Best,
Igor