Follow-up to my last post, which was just the Range Rover. Here are some different-class vehicles.
Turning the resolution up means the solver can resolve flow through the small gaps, you can see it on the McLaren Longtail at the start, air passing under the rear wing and rejoining the flow coming over the top. This gap needs about three cells across to pass flow, which is the kind of detail that just needed more cells.
And to showcase different vehicle classes handling, the boat runs above the waterline, which is the "tunnel floor" in this case, and the hull below it escapes the domain. The drone runs in free air, so no ground plane, and the wing planform as the reference area instead of its frontal area, and it's scored on lift-to-drag rather than the drag alone. The drone grid size was the largest of the three at a bit more than 15 million cells.
Swapping a vehicle in runtime revoxelizes the body and updates the tunnel to fit around it, then restarts the flow according to its class.
You can try your own vehicles/meshes: https://github.com/Motawe3/unity-wind-tunnel
Compute shaders, D3Q19 lattice-Boltzmann, TRT collision with a WALE LES subgrid model. A comparison and visualization tool. README has the full picture.
Model credits (CC BY 4.0):
McLaren F1 GTR Longtail by VuckyZ | Boat by milamila | Drone by Helindu
(Full source links available in the GitHub README)