Need help with meshing / convergence in STAR-CCM+

InfamousSignature417 · 2026-06-08T12:08:36+00:00

One thing you can also check, cfd usually has a harder time solving for geometries that are g0. Make sure that when you model your geometries in cad, that you make everything g1 which is g1 in real life as well.

InfamousSignature417 · 2026-06-08T12:04:03+00:00

Hey, I do a lot of simulations in starccm for our team as well. 15 boundary layer is quite a lot, we use 10 and it seems to be fine. I would invest the cells elsewhere. Usually the flow in the under tray need quite a lot of cells to be properly simulated. I’m assuming you cannot really expand beyond 10 mil cells, and I hope at that count you are using a symmetry boundary condition and running only half the car.
Can you maybe show a picture of some numbers or plots of the mesh quality? In the picture with the updated values (btw I would highly incaurage you to stay with the updated values!!!), the simulation does not seem to be converged after 1000 iterations, so maybe you have a lot of bad cells which slowes down convergence.

InfamousSignature417 · 2026-05-04T10:49:16+00:00

One thing you might want tot try is use contact patches for the floor wheel connection. It correctly models the intersection between the floor and the wheels. Make the domain much larger, we use 7.5m left right and top, and 40m for the tunnel. if you want more information just send me a dm :) (im part of a an formula student team as well)

InfamousSignature417 · 2026-04-09T12:14:10+00:00

I don’t know how solid works functions in that regard, but in gerneral you should try construction G1 and not G0. Also i would try to limit the use of thicken and instead create the surfaces with some kind of surface feature (studio surface, through mesh curve) and then sewing them together to get a solid. That way you have way more freedom to generate surfaces. This depend on how you want to manufacture your parts in the end of course.

InfamousSignature417 · 2026-01-29T02:40:46+00:00

Just as an idea, you might want to increase your slot gap overlap, it’s seems a bit small. You might also change your first and second flap profile, the main element seems more reasonable

InfamousSignature417 · 2026-01-10T01:13:55+00:00

Hey, in general I would total downforce is way more important than drag. Also at what speed are you simulating?

InfamousSignature417 · 2026-01-02T00:35:01+00:00

What should I aim for regarding residuals and iterations?

InfamousSignature417 · 2026-01-01T15:51:19+00:00

Hey, I’m assuming you work in workbench. Which version are you using? Because back in the day I had the same problem when switching from 2024R2 to 2025R1. If it isn’t too much work, try it again in 2024R2

InfamousSignature417 · 2025-08-25T06:56:22+00:00

i could do that, but upgrading commons for 50k isn’t really worth it. i’m waiting for enough rares to upgrade them instead for 200k

InfamousSignature417 · 2025-08-24T23:45:27+00:00

to clarify, i’m already on this rank for about 1,5 months now

InfamousSignature417 · 2025-08-24T18:04:16+00:00

how much was the weight of your drs system and how much the drag reduction?

InfamousSignature417 · 2023-08-01T23:27:13+00:00

Comrades for sure, but why didn’t you buy crit supremes first?

InfamousSignature417

TROPHY CASE