Hello, I am having a velocity issue reported in my simulation after following along with the FSAE incompressible flow tutorial. Here is the error message:
Here is a link to my simulation as well. I went through the process fairly slowly, and I do not immediately spot any meshing issues at the coordinate described in the picture above.
Hi @SamJ_doorLink,
Thanks for using the forum!
I see that you were diligent in setting up the mesh with region and local refinements. These divergence errors occur near locations where the surface mesh is a bit coarse or the transition between the surface and volume mesh is not properly captured.
In the tutorial case, the number of boundary layers is set to 3. Please use 5 layers to capture the transition better. This should probably solve the divergence issue.
I will go ahead and inform our team to make this change in the documentation as well.
With Kind Regards,
Ajit
Hello @ananthu_ajit,
I tried increasing the number of boundary layers from 3 to 5 like you mentioned but it looks likely to fail again. At the very least it will finish with poor convergence. Can you spot any steps I missed in the tutorial? I can’t find anything.
Hi, i think it is just because your mesh is to coarse, try to decrease the local element size where the simulation start to diverge.
Thank you for the suggestion. So far, the simulation is running quite a bit smoother as it previously began to diverge at around 65 timesteps and it has made it to just over 90 with a much smoother profile. I will keep sending updates. If it diverges again, I will run the mesh quality check to get a closer look at what is going on. Odd that a tutorial is requiring this much editing from the documentation’s specifications.
