Hello
Trying to run a first simulation around car following the settings of the " Aerodynamics Simulation of Flow Around a Vehicle" tutorial.
interested in seeing the effect of the small additional lip under the bumper. hoping to run another one with a different lip.
Meshing fails everytime after about 5 min, with this log or similar :
Model import took 2.536022354s.
Maximum precision of model and its entities: 8.606252826087606e-06 m.
Absolute small feature tolerance: 6.909722222222222e-06 m.
Code: 1102 String: Cannot resolve intersecting mesh between face 11 and face 11 at (-16.758981128535549, -2.0452509004476882, 1.6333312244812315), model may self intersect
When I make a point with these coordinates to investigate and understand where the problem is it appears outside of the Flow region…
Re-set this project multiple times with different settings, small feature tolerance and other meshing settings and no change.
Corrected this mesh several times and last checked before export it did not have self intersecting edges…
Did not show any errors or faults on import.
Would appreciate help as to where to look for errors or mistakes.
Thanks !
Hello and welcome to SimScale!
I took a look at your model. I believe part of the issue is due to the fact that your starting geometry is a faceted .stl surface mesh, which can be problematic compared to a B-rep (CAD) part like a Parasolid or STEP file.
Are you able to convert this file to a CAD format, or go back to the original CAD (prior to .stl export) and work with that starting geometry? I know this conversion can be done in many CAD packages, however it will create a CAD face for each facet which is non-ideal. Getting the original CAD surfaces would be best.
A few other recommendations:
- Delete the slatted radiator and either block off this surface or replace with a comparable volume as a porous region. For simplicity, I would just block it off.
- Cut the tires at the static loaded radius/ride height (whichever is easiest to obtain) and consider extending small extrusions between the tire and road in this critical area. See these threads: Mesh problems due to intersections , Velocity field is diverging at a point - #2 by Ricardopg
- It looks like you could exploit symmetry (about the y axis) on your model, assuming you do not want to simulate a yaw condition.
- Your tunnel could be a bit smaller in the y/z directions, which could cut down on the mesh size a bit.
- You could also experiment w/ the “Hex Dominant” meshing option in SimScale, which is often preferable for external vehicle aero simulations.
Please keep us posted on your progress…this is a great Miata model and should be very popular here on the Community!
–Nolan