hello, I'm testing my F1 in Schools car in Autodesk CFD 2026 to figure out the drag force/drag coefficient and lift. I use the following materials:
1. wind tunnel: air
2. car: f1iS block (custom properties, density of 0.163g/cm^3)
and the following boundary conditions:
1. wall facing my car: velocity inlet (15m/s) direction faces the car
2. back wall: pressure outlet (1 atm)
3. all other 4 faces: slip/symmetry
I have tried running this wind tunnel setup on different models, different devices and different versions of the software. I always get a negative drag value with the wall calculator. (I make sure the only forces acting on the car are calculated, through the faces selection option in the wall calculator.) Help would be appreciated.
Heres my design study with the car, setup and last set of results: https://drive.google.com/file/d/142QyURUit0M7iwr1mJwP42T6d17XF-ly/view?usp=sharing
(the convergence plot looks unstable but ive done the analysis previously with up to 3000 iterations yet i still got negative drag values)
@Anonymous @matt.bemis @john.holtz @frederic.gaillard.7
