[MVRC] Mantium Virtual Racecar Challenge 2025 (Grand Prix Cars)

[k.ko100v]

Hello,

Congratulations to JJR and to everyone who made it to the podium!
I'm also very impressed by the performance of the new participants.

My last two runs crashed with the same error:

Mflow: 2403a
Could someone provide insight into what might be the root cause?

One more question: Is it possible to obtain the official race reports? I noticed a negative delta in both Cl and COP, and I’d like to investigate where it might have originated.

I suspect that some of the rear components, such as the wings or diffuser, are stalling, but I need to identify which one.

EDIT: I think I found the error root cause - Windows updates stops the process.

Regards,
Krasen

[yinlad]

Hello,

Congratulations to JJR and to everyone who made it to the podium!
I'm also very impressed by the performance of the new participants.

My last two runs crashed with the same error:
https://imgur.com/YgOvGI0.jpg
Mflow: 2403a
Could someone provide insight into what might be the root cause?

One more question: Is it possible to obtain the official race reports? I noticed a negative delta in both Cl and COP, and I’d like to investigate where it might have originated.

I suspect that some of the rear components, such as the wings or diffuser, are stalling, but I need to identify which one.

EDIT: I think I found the error root cause - Windows updates stops the process.

Regards,
Krasen

You should have had the official report through by email this morning. I did at least

[stefano.segneri]

Hi everyone, I have a question about rule 7.1.3 regarding the power unit inlet:
"This template must not intersect any other parts or templates with the exception of the engine intake plenum."

I cannot find any part named "engine intake plenum" among the supplied parts/volumes. Is it referring to the "MAND_Engine_inlet_Volume_V01" part?
Thanks in advance and happy developing to all!

I don't believe there's a engine intake plenum that interferes with the template anymore so that shouldn't be something to worry about anymore with 7.1.2 in place

Thanks for your reply. I’m wondering if the intersection between the power unit inlet and MAND_Monocoque_V01 is accepted by the rules.

[stefano.segneri]

Good morning everyone!
I noticed that in the new version of Mantium Flow, the wheel friction boundary condition is no longer included (in the MVRC setup), whereas it was present last year. Will it be the same for the races? No more nutkRoughWallFunction?
Thanks in advance!

[LVDH]

Good morning everyone!
I noticed that in the new version of Mantium Flow, the wheel friction boundary condition is no longer included (in the MVRC setup), whereas it was present last year. Will it be the same for the races? No more nutkRoughWallFunction?
Thanks in advance!

That is not intentional. I will have a look tomorrow.


I finally added the results to the page:
https://mantiumchallenge.com/results-mvrc-miami-2025/
Please have a look and potentially contest my findings about rule violations on your cars:

HermesMotorsport: 9.1
Koldskaal: 2.3
Kostov Racing: 2.5, 9.1, 11.3
Panthera: 2.1, 9.1.3
Pure Power Racing: 9.1.3
Rusted GP: 9.1 (multiple times), 10.3, 11.3, 12.1

Remember, if you get caught with one, doing it again this season will cause a penalty. This race, RustedGP had so many issues, that I had to hand him one already.
Also pretty much every team ignored rule 2.1. I was pretty nice about this, but from next race on, you definitely also have to follow that one. Receiving a penalty for not naming the submission correctly would be a bit embarrassing.

[The Rusted One]

Small mistake, but I believe the rh, power, and rake numbers are in the wrong columns.
On the other hand, that's actually embarrassingly dumb way to lose a podium... Half my car was aligned incorrectly

[LVDH]

Good morning everyone!
I noticed that in the new version of Mantium Flow, the wheel friction boundary condition is no longer included (in the MVRC setup), whereas it was present last year. Will it be the same for the races? No more nutkRoughWallFunction?
Thanks in advance!

I can now confirm that this is somehow not in the current version of MFlow. I will fix this next Monday together with some other minor issues, I have discovered.

As we took a bit to update the rules with the radius rule in the rear and the next race is coming up, we decided to wait with this until the third race!

We have taken a look into the issue with the misaligned suspension parts, when using the stp assembly and should be able to upload them today or on Sunday, as we would like to test and confirm that the issue is solved.

Small mistake, but I believe the rh, power, and rake numbers are in the wrong columns.
On the other hand, that's actually embarrassingly dumb way to lose a podium... Half my car was aligned incorrectly

Looks like we both did a similar mistake then. I was pretty surprised to see that you missed out on so many regulation surfaces, but I guess, I now understand.

[Ft5fTL]

Good morning everyone!
I noticed that in the new version of Mantium Flow, the wheel friction boundary condition is no longer included (in the MVRC setup), whereas it was present last year. Will it be the same for the races? No more nutkRoughWallFunction?
Thanks in advance!

I can now confirm that this is somehow not in the current version of MFlow. I will fix this next Monday together with some other minor issues, I have discovered.

As we took a bit to update the rules with the radius rule in the rear and the next race is coming up, we decided to wait with this until the third race!

We have taken a look into the issue with the misaligned suspension parts, when using the stp assembly and should be able to upload them today or on Sunday, as we would like to test and confirm that the issue is solved.

Lambda2 looks broken aswell on paraview.

[LVDH]

So, after the team confirmed that the new CAD parts are correct, I have uploaded a new version to the challenge page.

If I understood correctly, you should not see any difference, if you were using the separated step or stl files. The stp assembly now does not exist anymore. Keep in mind, the step files we provide, are for convenience, as your CAD software might like them. The stl files are the ones to go by, esp. for the CFD simulations.

I only now noticed that the next race will be next week.
Because of that, I will not change anything in MFlow. We will have to wait for that turbulence update until race 03.
This is to not have the teams with weaker hardware have to go crazy with running enough simulations until next weekend.

Lambda2 looks broken aswell on paraview.

The iso surface looks misaligned when using rake and ride height adjustments?

[AeroStarKnight]

If I understood correctly, you should not see any difference, if you were using the separated step or stl files. The stp assembly now does not exist anymore. Keep in mind, the step files we provide, are for convenience, as your CAD software might like them. The stl files are the ones to go by, esp. for the CFD simulations.

Thank You for the updated parts!
I checked the parts. They are identical, no difference at all. I guess the problem was with the position. But since we don't have the STP Assembly, how can we place the parts in the correct position?

Sorry if this is a dumb question, but I cant figure out what the correct position is for the suspension. Please tell me how can I place them correctly.
Thank You.

[CAEdevice]

But since we don't have the STP Assembly, how can we place the parts in the correct position?

In theory, any CAD software should allow you to import individual parts, placing them so that their coordinate system matches that of the assembly you are creating. This way, they should be properly aligned. Which CAD software are you using?

[LVDH]

From my experience, every software will have options on how to import the files.
This can be a bit obfuscated / confusing, though.
The ultimate test you can do is use MFlow.
I know that not every team uses it. And that it is perfectly fine.
Just consider that is is basically just an executable to have on your PC (yes, Windows may at random, without warning, just delete it...).
But if you work with the supplied stl files, together with MFlow, you are very much doing what will be the official simulation. So, just to at least visually understand, if you are doing everything correctly, I advise to load the car once into MFlow to just have a look at it.

[Ft5fTL]

Lambda2 looks broken aswell on paraview.

The iso surface looks misaligned when using rake and ride height adjustments?

Something like this:

If you look at the front wing leading edge and suspensions you will understand what i meant.

Also i'm still getting maximum allowed dimension error when creating cases.

[AeroStarKnight]

But since we don't have the STP Assembly, how can we place the parts in the correct position?

In theory, any CAD software should allow you to import individual parts, placing them so that their coordinate system matches that of the assembly you are creating. This way, they should be properly aligned. Which CAD software are you using?

Oh Got it. So I just need to match their planes and the Origin and it will be automatically at the right place. Thank You So Much !!! I am using Solidworks.
I updated my parts. Thank You!
What Software are you using ?

[AeroStarKnight]

From my experience, every software will have options on how to import the files.
This can be a bit obfuscated / confusing, though.
The ultimate test you can do is use MFlow.
I know that not every team uses it. And that it is perfectly fine.
Just consider that is is basically just an executable to have on your PC (yes, Windows may at random, without warning, just delete it...).
But if you work with the supplied stl files, together with MFlow, you are very much doing what will be the official simulation. So, just to at least visually understand, if you are doing everything correctly, I advise to load the car once into MFlow to just have a look at it.

Yes. I understood. I have installed MFlow and will run Simulations as soon as my design is ready.
Thank You!