CFD PF900 8 Fins 350mm at 20 Deg Equal AoA Rev B4 Filleted

Project Support
1

Creation time
Mar 30, 2023 8:43 PM
End time
Mar 30, 2023 9:32 PM
Job was prepared successfully.
Run pre-processing finished.
The solution diverged, please check your simulation setup. Divergence can also be caused by bad elements in the mesh. Such elements tend to exist near walls and sharp corners. Visually inspect your mesh to locate them and re-mesh with additional refinements in their vicinity. If you are confident about the mesh-quality, please reduce relaxation factors and use more conservative numerical schemes.

The project name is under SimScale user “spquinn” under project “CFD PF900 8 Fins 350mm at 20 Deg Equal AoA Rev B4 Filleted”
and this is a Public Project, so any SimScale user should have access to it. I tried to share this project with the support staff, but I didn’t know a username to put in the share box.

I tried numerous different ways to try to fix this by:

  1. changing the mesh several times, including try different regional refinements,
  2. changing the earlier recommended parameters of the custom boundary conditions (as suggested by SBLOCK that worked for another project but not for this one),
  3. changing the 3D drawing to remove any sharp edges from the entire drawing

I tried other changes too, but all of them end with the same error as shown above. Any help you can give is much appreciated.

2

Hey there, and thanks for using the forum!

Please always include the URL to your project, so we can provide the best possible support.

3

Hello @spquinn ,

I took a look at your model and made a few adjustments to the BCs. Rather than setting all sides of the outer box to the Atmosphere BC (inlet/outlet), I set 5/6 of them to a free-slip wall, and then just set one to this BC. This will avoid any ambiguity at the corners of the box.

I reset all the numerics back to default and it ran nicely out to 200 iter. You can run with it from here (I shared my project back with you). Partially converged velocity field:

Screenshot 1 (8)
Screenshot 1 (8)1440Ă—1080 89.1 KB

1 Like
4

Okay. Here is the URL:

or if that doesn’t work try this one (not sure which one you can see):

c246d-a8d2-425e-b96f-4277cd6b13b4%2Cservice%3ASIMULATION%2Cstrategy%3A2

5

Hello @nhalliday,

Okay. I’ll check it out later today (Los Angeles time), but your image of the results looks really good. The only thing that looks a little odd, is that there are EIGHT somewhat discrete regions of outward airflow shown in the image – but in reality, the outflow would be completely uniform (not segmented like that). But I’m guessing that effect is probably nothing to be concerned with. I’ll check later today and get back to you, but it looks like you fixed it. Thanks!

6

Hello @nhalliday

Thank you. Yes i checked, copied, modified slightly, and ran the simulation myself. Looks good now! Much obliged.