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