I am trying to simulate external airflow around 2 airfoils with an Incompressible Simulation, but the meshing failed. Below are the error messages, and I am not sure about how to proceed from here. I created my geometry in AutoCAD by projecting 2D coordinates of NACA0012 airfoil to 3D.
I can’t seem to make my project public, but the name is “10 Close”
Any help would be appreciated!
Hi @Semix,
Thank you for posting on the forum!
Even if your project is private, you can still share the link with us by following the steps outlined in this forum guide:
Since I currently don’t have access to your project, I can only speculate about the issue. To successfully run simulations on an airfoil, ensure it’s modeled as a closed body and then generate the flow region. These resources might be helpful in resolving potential challenges:
I hope this information helps.
Cheers,
Igor
Hi Igor,
Below is my link:
Is this alright?
Thank you!
Hi @Semix,
There seems to be a construction error coming from the fact you’ve imported the geometries as STL files. Since they are a simple profile extrusion, is it an option to export the CAD as STEP/Parasolid instead? SAT could also work.
Ps: Keep in mind the STL format is usually to be avoided for Incompressible OpenFOAM simulations. It’s faceted nature tends to generate issues in the CAD models and SimScale’s automatic facet splitting many times isn’t enough to solve them.
Cheers
Igor
Hi Igor,
Thank you for the advice. I just re-exported my file in the STEP format, but now there’s fault in the geometry. I’m not sure why this happened because it is the exact same file as the stl which worked fine with setting the flow volume.
With stl the error was in the meshing stage, but with STEP and SAT, the error happens when I import the geometry. Is this an issue with the way I made the model, and if so, are there any other methods I should pursue?
Thank you!
Semix
Hi @Semix,
Which CAD Tool are you using to Import the file? Maybe trying a different CAD tool works. As I had noted earlier, you have 2 simple extrudable shapes in your CAD (which could be generated using any CAD tool).
Maybe OnShape is a good alternative - it has a nice integration feature with SimScale and we use it internally for CAD.
Cheers
Hi Igor,
I just made my models in OnShape and tried again, but there’s another error (probably not due to geometry).
Here’s the link: https://www.simscale.com/workbench/?pid=3859881737854191294&mi=spec%3Aab0b4743-e217-4772-82fa-30b48795f10f%2Cservice%3AMESHING%2Cstrategy%3A8&sh=7
Do you know any possible solutions to this?
Thanks,
Semix
Hi @Semix,
The issue is that the region refinement you’ve set is leading to the generation of a very large mesh:
Calculating the volume for your Cartesian box:
10 m \times 2.75m \times 2.5m = 68.75m^3 \tag{1}
If a single regular tetrahendron volume is given by
V = \frac{a^3}{6\sqrt{2}}\tag{2}
The corresponding volume for a tetrahedron with an edge length of 0.01m would be \approx 1.2e-7 m^3. Dividing (1) by this value would provide the cell count of ~573M cells, which will always run out of memory, especially with the Community account which has limited access to processing cores.
A solution would be to increase this value to a reasonable amount given your domain’s size. This tutorial I’ve linked to earlier might provide a good guideline:
Cheers
Igor
