[MVRC] Mantium Virtual Racecar Challenge 2024 (Grand Prix Cars)

[Ft5fTL]

Can one of our Windows users help out here? I keep away from touching this part of MFlow. So we still use the same BlueCFD version we always did.
I am working on a big update which will be able to use the supplied Docker versions of OpenFOAM. But this will take a while...

getting this errors on bluecfd-2020:

[yinlad]

If you can export this control surface as an STL with triangles of constant 5mm size, then you will match what André uses for the official simulations.

Oh that's interesting, I thought it was 10mm for some reason. That might explain some of the cooling correlation issues I had

[peisari]

Hi everybody, new challenger here.

Sorry to bother you all but I'm struggling to understand one or two things about simulations settings and results:

1. In the special bc folder the volume flow values I input are the full car values or the half car values?
2. Are the cl and cd values i see on the output window already x2 or do i have to x2 them to obtain the full car values?
3. is there a way to import mesh or full domain results in paraview? i only see "partial" vtk outputs
4. is there a way to manually stop the simulation without losing the results? I'm using ctrl+c, but i can't post process the reults after that.

These questions have probably already been answered multiple times over the years, but it's difficult to find them in the old threads, sorry for that

[spacehead3]

Suzuka is now added to the lap sim webpage https://maxtayloraero.com/mvrc/

[Tzk]

Just a curious question regarding the simulator linked above: Why does the laptime get higher when CL is lowered beyond -11? I'm aware that this is a value MVRC usually doesn't reach, but i expected laptime to become minimal with more downforce, all other things staying equal. Am i being wrong here?

I tried with:
Suzuka, CD 1.5, Power 1, CoP 1.92 and then sweeping through CL from 0 into the negative values. From 0 to -10 the laptime gets lower, but once you pass -10 it rises again while Vmax still rises.

Monza: same values as above, Here Vmax drops after CL -8, which is quite counter intuitive. Same for laptime, it falls until -10 and then rises again while the vmax drops further.

Monaco: same values as above, at CL -29 Vmax becomes negative?!

[CAEdevice]

The web version of Max's laptime simulator is based on a database built with interpolation. When you simulate a condition far from the focus (and not really representative of our cars) you might get non realistic numbers.

[LVDH]

Hi everybody, new challenger here.

Sorry to bother you all but I'm struggling to understand one or two things about simulations settings and results:

Nothing to apologize about. This is what the forum is here for.

1. In the special bc folder the volume flow values I input are the full car values or the half car values?

You do not have to input anything. If you are using an MVRC template and have the correct file names for the intake and exhaust part, MFlow will automatically set the correct values

2. Are the cl and cd values i see on the output window already x2 or do i have to x2 them to obtain the full car values?

They are correct as they are

3. is there a way to import mesh or full domain results in paraview? i only see "partial" vtk outputs

To load the full domain into Paraview, you have to open the *.case file. Likely your simulation was done in parallel (check the many processer folders). In Paraview there is a button somewhere where you tell Paraview that the case is decomposed. You have to check it...

4. is there a way to manually stop the simulation without losing the results? I'm using ctrl+c, but i can't post process the reults after that.

Yes, but you have to know what you are doing. You can set how often results are stored in the controlDict in the case folder. And you have to specify to start from latestTime. Then you can stop and restart as often as you want.

Can one of our Windows users help out here? I keep away from touching this part of MFlow. So we still use the same BlueCFD version we always did.
I am working on a big update which will be able to use the supplied Docker versions of OpenFOAM. But this will take a while...

getting this errors on bluecfd-2020:

Yeah, best is to stick to the supported version.

[G-raph]

Welcome to our new challengers!

The base car provided by Max is exactly what the Challenge needs. I think it needs to be better advertised, certainly on the Rules page but maybe also on the Linkedin page?

I also think competitors should be able to choose to run with the 2023 front and rear suspensions, if they don't have time / knowledge / will to design bespoke suspensions. Again, making that part of the offical Rules page would be great, as well as on Linkedin.

Still on the topic of suspensions, has anyone noticed that the Mandatory suspension parts (the minimal structural cylinders) and the legs we design in their regulation box are not positioned the same way in MFlow?

To fix the problem I had to include the internal brake duct cylinder as part of my suspension legs STL. The other solution I guess would be the join the legs to the mandatory part, but I don't now how to merge independant STLs.

[yinlad]

Still on the topic of suspensions, has anyone noticed that the Mandatory suspension parts (the minimal structural cylinders) and the legs we design in their regulation box are not positioned the same way in MFlow?

To fix the problem I had to include the internal brake duct cylinder as part of my suspension legs STL. The other solution I guess would be the join the legs to the mandatory part, but I don't now how to merge independant STLs.

Yeah, I merged my arms and the mandatory geometry to fix the problem, otherwise the ride height adjust got a bit funny and things stopped lining up

[yinlad]

11.3 The rear wing must be attached with at least three sections with one or two such sections inside of the volume RV_RR_WING_MVRC_2024_* attaching to the gearbox.

Is the intention of this rule to have the RW assembly attached to the gearbox by a pylon and the beam wing?

I'm not entirely sure it's possible to strictly meet the above requirement as it asks for 'one or two' sections to attach to the gearbox, but three attachments in total, all for parts within the overall RW volume which only intersects with the gearbox, I think.

Furthermore and wording aside, would a solution without a pylon be considered a violation of Appendix 4 wrt unrealistic design?

[LVDH]

Hi guys,
so I am back from a vacation and should be more responsive now again, leading up to our first race.
Yesterday, I sent out an email with details for the first race. Please make sure you received it. It is YOUR own responsibility to submit a car in time. There will be another reminder email next Saturday.



I will look into the suspension issue in MFlow. I am sure the morphing in MFLow expects only a single suspension part, so you indeed have to merge everything into one file. But it should be easy to update MFlow to morph multiple parts.
As suspensions are usually just an extruded profile part, I think everyone who is part of MVRC can do this.

11.3 The rear wing must be attached with at least three sections with one or two such sections inside of the volume RV_RR_WING_MVRC_2024_* attaching to the gearbox.

Is the intention of this rule to have the RW assembly attached to the gearbox by a pylon and the beam wing?

I'm not entirely sure it's possible to strictly meet the above requirement as it asks for 'one or two' sections to attach to the gearbox, but three attachments in total, all for parts within the overall RW volume which only intersects with the gearbox, I think.

Furthermore and wording aside, would a solution without a pylon be considered a violation of Appendix 4 wrt unrealistic design?

The rule is about AT LEAST three attachments. So you could use two going to the gearbox. Keep in mind, the car has to be symmetric.
And Appendix 4 is obviously very subjective. But only attaching the wing on the sides and then rather flimsy would indeed be a violation.

[G-raph]

I will look into the suspension issue in MFlow. I am sure the morphing in MFLow expects only a single suspension part, so you indeed have to merge everything into one file. But it should be easy to update MFlow to morph multiple parts.
As suspensions are usually just an extruded profile part, I think everyone who is part of MVRC can do this.

Thank you for looking into it.

There is no problem with the number of parts. You can put 10 parts in the suspension folder and they will all deflect the same.

It is just that the deflection will change based onthe size of the geometry on the outboard side.

Simple suspension legs extrusions in their regulation boxes will deflect one way.
Suspension + brake cylinder will deflect another way, and match the mandatory parts.
Suspension + brake cylinder + wheel arches and deflectors will deflect another way again, no longer matching the mandatory parts.

[LVDH]

Sounds like I did not get your initial post.
I know that the morphing is not perfect, I just assumed it was good enough for the small deformations we need when we stick to the rules.
Please show some screenshots, as I still do not fully understand the issue.

[yinlad]

Sounds like I did not get your initial post.
I know that the morphing is not perfect, I just assumed it was good enough for the small deformations we need when we stick to the rules.
Please show some screenshots, as I still do not fully understand the issue.

I think the crux of the issue is you end up with things like this, if you place the suspension shrouds as a single STL. Where as if you merge the Mandatory and custom part as one STL, they remain inline.

[yinlad]

It's launch time! I am happy to present my R01 car. It's a big step on from the car that finished the 2023 season, but the changes to tyre roughness, engine cover regulation volume and free suspension design make it almost impossible to compare the cars like for like.

Much of the early development focused on the cooling package. With the new/expanded regulation volume at the rear I did some experimenting with larger coke bottle areas and no louvres, but for my application found more performance chasing as tight a package as possible down the middle of the car and utilising louvres on the outer edge of the sidepod to facilitate cooling requirements for 100% power. Compared to the '23 car I was able to create a tighter fit around the internals with smaller louvre openings largely due to the work that went into creating optimal flow conditions up to the radiator via my entire revised inlet shape/position.

Front and rear wings are definitely in the 'evo' category over the 2023 designs. With changes to the front wing end plate being the most dramatic departure from last year. This was really only done to bring the car more inline with the spirit of the 2022 generation of F1 car and probably cost performance in that area.
The rear wing has slight revisions across most of it's geometry but is broadly the same concept/design. the changes primarily focused on squeezing out efficiency for Suzuka, but more on that later.

The floor body, diffuser and fences remain pretty much untouched from the end of 2023, with some tweaks underneath and on the floor edge for vortex control being the only updates.

The front and rear suspension are of course all new following the regulation changes and posed one of the bigger challenges due to their large impact on the flow across the entire car. I suspect they have facilitated most of the performance gains I have been able to extract for the car, but difficult to say for sure.

Ultimately I'm pretty happy with how the car has ended up for R01, it's definitely the most refined car I have produced in the few seasons I have competed in and it really pushed on my modelling ability and understanding of how this generation of car works, which is why I started taking part in MVRC to begin with.

As for the race itself, I've tested various different levels of downforce through some wing variations and found that my efficiency pretty much scales exactly with the lap time for this track, so across a boundary of +/- 1Cl I could extract a lap time that was within 0.05s of either end. I suspect this will be my downfall for competitiveness across the season as I struggle to mitigate the large drag impact the tyre roughness has had on the car.

We'll see if I can find some some efficiency gains in the days before the submission deadline, but I am not expecting much to change from here. I'm looking forward to what I am sure will be a nip and tuck season and eagerly await to see what everyone else has cooked up.