[MVRC] Mantium Virtual Racecar Challenge 2022 (Grand Prix Cars)

[LegendaryM]

I disagree - 4deg is pretty standard for optimizing more toward non-straight line conditions. But hey I don't run the challenge.

I measured.
Supposing most corners aren't tighter than 50m in radius and the actual trajectory has a radius of 75m, then:
- without slip angle, airflow has a yaw angle of 2.7° at the front axle, 1.4° mid car, and 0° at the rear axle.
- with slip angle, the above numbers are even smaller or negative.
A 4° angle can only be seen at the front axle on a 50m radius trajectory, without any slip. And that starts being a tight corner, where aero isn't that crucial. So, i'm really not sure about optimizing around that.
And then we have all the straight line conditions.

Although the aero forces are reduced for low speed corners, they are still important - every bit of extra grip helps here when they are so time critical. Especially with how things have gone in the last 10 years or so with half the tracks on the f1 calendar being street circuits, aero performance in low speed corners is probably the most important for overall championship standing. Once you relax this assumption the yaw angle you need to optimise for becomes much higher. Furthermore, any wind angle can have a bigger effect in low-speed corners as the speeds are lower, so the yaw angle can be even higher.

I'm not sure how the slip angle of the wheels affects the car yaw angle, the car is still going round the corner.

I do agree that its probably best to stick to straight-ahead for MVRC, for the simple reason that it takes half the time. But it is worth bearing in mind its a very different condition to what F1 cars are designed for nowadays.

[variante]

Although the aero forces are reduced for low speed corners, they are still important

For reference, downforce in F1 contributes to roughly 27% of the G forces in a 50m radius trajectory, to 42% in a 75m radius trajectory, and to 75% in a Copse-like corner.

I'm not sure how the slip angle of the wheels affects the car yaw angle, the car is still going round the corner.

All 4 tires experience some slip during turning, meaning that -in a way- the whole car slips a little bit.
That partially cancels out the angles we were talking about.
Check out the schemes here:
https://www.sciencedirect.com/topics/en ... -cornering

[CAEdevice]

Hi, what about the next race (Monza)? Is the date confirmed? Will the rake setup be allowed? Which is the rotation axis for the rake? I have the impression that considering the front wheels axle as the origin we would have a very large ground clearance, maybe a reference about in the middle of the wheelbase would be more realistic.

[LegendaryM]

Although the aero forces are reduced for low speed corners, they are still important

For reference, downforce in F1 contributes to roughly 27% of the G forces in a 50m radius trajectory, to 42% in a 75m radius trajectory, and to 75% in a Copse-like corner.

I'm not sure how the slip angle of the wheels affects the car yaw angle, the car is still going round the corner.

All 4 tires experience some slip during turning, meaning that -in a way- the whole car slips a little bit.
That partially cancels out the angles we were talking about.
Check out the schemes here:
https://www.sciencedirect.com/topics/en ... -cornering

I think 27% is still significant if that's correct. I see what you mean about the slip angles, thanks for the link - I haven't looked at vehicle dynamics in a while. All I know is when I worked in F1 in 2017 the low speed corner condition was what we primarily wanted downforce at, with about 8 degrees yaw at the front and 3 at the rear, so we must be missing something with our calculations here.

[CAEdevice]

The point is that we must balance the computational power available and to simulate only one condition is 99% enough to differentiate between a good design ad a bad car.

There at least two other details that we are not considering, but important in real cars: brakes cooling flow and transient simulation (including Von Karman vortices detachement), maybe three with gravity center height. Anyway: it would be impossible to compute a transient simulation for 11 teams, with at least a couple of configurations per team.

What would be possibile instead, is adding a special final race, only for the best three teams, with more complete simulations (and finer mesh) in order to assign the title.

[AratzH]

Just checking that the deadline is in 6 hours, not 30 hours... using 24:00 as the time is liable for this kind of confusion

Being 9hours behind official timing has not helped aaand, I missed the deadline

Also, updated to the latest parts and solver and I get a new error...
Seems to be related to the exhaust outlet boundary condition:

Code: Select all

Pstream initialized with:
    floatTransfer      : 0
    nProcsSimpleSum    : 0
    commsType          : nonBlocking
    polling iterations : 0
SigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0


potentialFlow: Operating solver in PISO mode

Reading velocity field U

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--> FOAM FATAL IO ERROR: 
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--> FOAM FATAL IO ERROR: 
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--> FOAM FATAL IO ERROR: 
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--> FOAM FATAL IO ERROR: 


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Cannot find patchField entry for MAND_Exhaust_Out_V04
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Cannot find patchField entry for MAND_Exhaust_Out_V04
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Cannot find patchField entry for MAND_Exhaust_Out_V04
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Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
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Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04

Cannot find patchField entry for MAND_Exhaust_Out_V04

Cannot find patchField entry for MAND_Exhaust_Out_V04

Cannot find patchField entry for MAND_Exhaust_Out_V04







Cannot find patchField entry for MAND_Exhaust_Out_V04

Bumping this again. I could not enter race, and since MFlow2207e-windows all my sims crash at the same point and with the same error.

On a brighter note, here's what would have been my entry:

[CAEdevice]

Bumping this again. I could not enter race, and since MFlow2207e-windows all my sims crash at the same point and with the same error.

On a brighter note, here's what would have been my entry:
https://ibb.co/NtJLShq
https://ibb.co/rkK69CW
https://ibb.co/VxwJwTK

Clean car, I hope you can race soon.

By the way, any news from the staff?

[LegendaryM]

Can I have some clarification on rule 10.2:

Every cross section in the Y-plane inside of the volume RV_FRT_WING_VOL_V01 must produce no more than four closed sections.

Does this mean: closed sections <=4, open sections are unlimited? Or does it mean: all sections must be closed, no more than 4 closed sections. I.e. would geometry like this, with 4 closed sections and 1 open be allowed:

[RicME85]

IMO that is legal. My interpretation is that the rule is about limiting how many wing profiles you have in the FW volume, much like the official F1 rules

[LVDH]

Just checking that the deadline is in 6 hours, not 30 hours... using 24:00 as the time is liable for this kind of confusion

Being 9hours behind official timing has not helped aaand, I missed the deadline

Also, updated to the latest parts and solver and I get a new error...
Seems to be related to the exhaust outlet boundary condition:

Code: Select all

Pstream initialized with:
    floatTransfer      : 0
    nProcsSimpleSum    : 0
    commsType          : nonBlocking
    polling iterations : 0
SigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0


potentialFlow: Operating solver in PISO mode

Reading velocity field U

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--> FOAM FATAL IO ERROR: 
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--> FOAM FATAL IO ERROR: 
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--> FOAM FATAL IO ERROR: 
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--> FOAM FATAL IO ERROR: 







--> FOAM FATAL IO ERROR: 


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Cannot find patchField entry for MAND_Exhaust_Out_V04
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Cannot find patchField entry for MAND_Exhaust_Out_V04
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Cannot find patchField entry for MAND_Exhaust_Out_V04
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Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
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Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04

Cannot find patchField entry for MAND_Exhaust_Out_V04

Cannot find patchField entry for MAND_Exhaust_Out_V04

Cannot find patchField entry for MAND_Exhaust_Out_V04







Cannot find patchField entry for MAND_Exhaust_Out_V04

Bumping this again. I could not enter race, and since MFlow2207e-windows all my sims crash at the same point and with the same error.
...

Please try the newest version.

Can I have some clarification on rule 10.2:

Every cross section in the Y-plane inside of the volume RV_FRT_WING_VOL_V01 must produce no more than four closed sections.

Does this mean: closed sections <=4, open sections are unlimited? Or does it mean: all sections must be closed, no more than 4 closed sections. I.e. would geometry like this, with 4 closed sections and 1 open be allowed:

I will check the wording on this. But yes, the intention is to have a nose and max four wing profiles.

Hi, what about the next race (Monza)? Is the date confirmed? Will the rake setup be allowed? Which is the rotation axis for the rake? I have the impression that considering the front wheels axle as the origin we would have a very large ground clearance, maybe a reference about in the middle of the wheelbase would be more realistic.

Plan is to hold the race as announced.
Now once more, I am a bit behind of where I wound want to be. I have all results and reports of the race. However only since yesterday. Now they have to go to Christian to produce the video. Also, I still have to conduct the scrutineering which will probably only happen tomorrow morning. So we will only see the full results in the coming few days.
With this delay, we will pretty much keep the rules as they are. So we will keep the 0 deg rake. This will change soon. The feature is implemented in MFlow but I do need to create new suspension parts and test it. I am a bit tired of all the bugs you guys find...
Today or tomorrow, I will send out the reports. Please keep the results to yourselves until the results get released! Christian is nice enough to keep our challenge alive and produce a cool video for us. However he is your competitor and could gain an advantage by knowing the results before you guys do. That is why I want to send out the results at the same time he gets them. But if you start posting results ahead of the video, this workflow does not make any sense.

[CAEdevice]

It is not a issue if Christian knows the results a couple of days before us. The advantage is small after the first race and negligible, in my opinion, after the following races, when numbers change a bit from race to race.

[Alonso Fan]

Can I have some clarification on rule 10.2:

Every cross section in the Y-plane inside of the volume RV_FRT_WING_VOL_V01 must produce no more than four closed sections.

Does this mean: closed sections <=4, open sections are unlimited? Or does it mean: all sections must be closed, no more than 4 closed sections. I.e. would geometry like this, with 4 closed sections and 1 open be allowed: https://i.imgur.com/sSLLFNA.png

In my understanding this is legal because you have 4 closed sections and 1 open section, and there is no mention of open sections in the wording of the rules.

Also tks for the wing profiles haha

[CAEdevice]

Can I have some clarification on rule 10.2:

Every cross section in the Y-plane inside of the volume RV_FRT_WING_VOL_V01 must produce no more than four closed sections.

Does this mean: closed sections <=4, open sections are unlimited? Or does it mean: all sections must be closed, no more than 4 closed sections. I.e. would geometry like this, with 4 closed sections and 1 open be allowed: https://i.imgur.com/sSLLFNA.png

In my understanding this is legal because you have 4 closed sections and 1 open section, and there is no mention of open sections in the wording of the rules.

Also tks for the wing profiles haha

Actually open sections does not exists (or I did not understand the wording of the rule).

In the image I see 4 closed sections and a portion of another closed section: the sum is more than 4.

[Alonso Fan]

Can I have some clarification on rule 10.2:

Does this mean: closed sections <=4, open sections are unlimited? Or does it mean: all sections must be closed, no more than 4 closed sections. I.e. would geometry like this, with 4 closed sections and 1 open be allowed: https://i.imgur.com/sSLLFNA.png

In my understanding this is legal because you have 4 closed sections and 1 open section, and there is no mention of open sections in the wording of the rules.

Also tks for the wing profiles haha

Actually open sections does not exists (or I did not understand the wording of the rule).

In the image I see 4 closed sections and a portion of another closed section: the sum is more than 4.

In my understanding (I could be wrong), since the only domain being considered here is the front wing volume, the portion of the nose inside the volume would be considered an open section as it only has 2 sides inside the section (one straight and one curved).

Will need to get a lawyer to confirm though haha

[AratzH]

Being 9hours behind official timing has not helped aaand, I missed the deadline

Also, updated to the latest parts and solver and I get a new error...
Seems to be related to the exhaust outlet boundary condition:

Code: Select all

Pstream initialized with:
    floatTransfer      : 0
    nProcsSimpleSum    : 0
    commsType          : nonBlocking
    polling iterations : 0
SigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0


potentialFlow: Operating solver in PISO mode

Reading velocity field U

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--> FOAM FATAL IO ERROR: 
[2] 
--> FOAM FATAL IO ERROR: 
[0] 
--> FOAM FATAL IO ERROR: 
[15] 
--> FOAM FATAL IO ERROR: 
--> FOAM FATAL IO ERROR: 
--> FOAM FATAL IO ERROR: 
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--> FOAM FATAL IO ERROR: 
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--> FOAM FATAL IO ERROR: 
--> FOAM FATAL IO ERROR: 

--> FOAM FATAL IO ERROR: 

--> FOAM FATAL IO ERROR: 

--> FOAM FATAL IO ERROR: 







--> FOAM FATAL IO ERROR: 


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Cannot find patchField entry for MAND_Exhaust_Out_V04
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Cannot find patchField entry for MAND_Exhaust_Out_V04
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Cannot find patchField entry for MAND_Exhaust_Out_V04
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Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04
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Cannot find patchField entry for MAND_Exhaust_Out_V04
Cannot find patchField entry for MAND_Exhaust_Out_V04

Cannot find patchField entry for MAND_Exhaust_Out_V04

Cannot find patchField entry for MAND_Exhaust_Out_V04

Cannot find patchField entry for MAND_Exhaust_Out_V04







Cannot find patchField entry for MAND_Exhaust_Out_V04

Bumping this again. I could not enter race, and since MFlow2207e-windows all my sims crash at the same point and with the same error.
...

Please try the newest version.

I can confirm new version fixed the issues!