Hi @cyrus_costa,
One difference I can notice between the projects is this extra refinement:
Which might be causing all the trouble.
One piece of advice we’ve already provided and that I’d like to stress is for you to extend your domain and use the symmetry of your model in your favor. Just split the car in half and only simulate it’s symmetrical part as in this tutorial:
This will save half the resources you’d spend on this simulation.
Another piece of advice is to copy the refinement options in the tutorial I’ve shared above. I feel like a better approach for external aero cases is to rely more on volume refinements for the close/far fields to best capture the wake region than to add the refinement to specific surfaces.
Cheers
Igor