## 2022 cars 'porpoising' at high speed

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johnny comelately
johnny comelately
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Location: Australia

### Re: 2022 cars 'porpoising' at high speed

Do they really need an algorithm, is it not possible to simply look at the data and see if the peaks and occurrences exceed their arbitary limits?
An absurd situation where their rules create a problem then as a solution they creat another rule...
Anyway it may be and of an era, the cars looked much better...sort of a self-solving problem
Last edited by johnny comelately on Sat Jul 02, 2022 1:37 pm, edited 1 time in total.

DChemTech
DChemTech
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Location: Delft, NL

### Re: 2022 cars 'porpoising' at high speed

johnny comelately wrote:
Sat Jul 02, 2022 9:06 am
Do they really need an algorithm, is it not possible to simply look at the data and see if the peaks and occurences exceed their arbitary limits?
An absurd situation where their rules create a problem then as a solution they creat another rule...
Anyway it may be and of an era, the cars looked much better...sort of a self-solving problem
What you describe is something I would refer to as an algorithm...

But probably one that would not work well, because, as I think henry brought up earlier, how will you deal with brief, incidental breaches due to gusts, bumps, etc? How often do these limits need to be exceeded, and at what interval? The proposed calculation accounts for that, because it calculates over a stretch of the track rather than just using instant values.

Red Rock Mutley
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Joined: Sat Jul 28, 2018 4:04 pm

### Re: 2022 cars 'porpoising' at high speed

KeiKo403 wrote:
Thu Jun 30, 2022 9:48 pm
Could the FIA have an issue here? The measures are being brought in on safety grounds to drivers health.

If enough teams get together and are able to 100% attribute bottoming/porpoising to the quality of the tracks surface then in theory the FIA have failed to ensure that the GP venue is fit for this era of regulations
I think it is unlikely the FIA will want to set that precedent. In effect, bending the circuit rules to suit one particular formula

The circuit rules are separate and distinct from the formula rules, albeit they are related at arm's length. The general principle is that the circuit must be safe for the formulas it is licenced to run. And the cars must be safe running on those circuits (not the other way around). There is an overarching proviso that those rule sets must be compatible, so inevitable there is some horse-trading going on behind the scenes to balance the polycentric needs

Once the rules are set, the precedent is that any car unable to safely run on the circuit is excluded from the event

Edax
Edax
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### Re: 2022 cars 'porpoising' at high speed

continuum16 wrote:
Fri Jul 01, 2022 6:26 pm
An article from motorsport.com has a better breakdown of the equation.
https://www.motorsport.com/f1/news/the- ... /10331177/
https://cdn-3.motorsport.com/images/mgl ... tric-1.jpg

Some quips from Tombazis:
"In this first implementation of the AOM, the FIA recognises that it primarily addresses the issue of grounding, but not the issue of pure aerodynamic oscillations." Ironic for a term called "aerodynamic oscillation metric"

"More analysis needs to be carried out in order to best implement additional terms that will capture aerodynamic oscillations, provided of course they are proven to cause driver discomfort and safety issues." Not surprised to see this is probably not the final form

Interestingly there are also things like "jokers" where you can exceed the limit by a certain amount at three races? The possibility of downforce changes/reductions for 2023? This keeps getting weirder. But at least we got to see the equation!
I am surprised by the simplicity of this equation.

If I look at the footage there is bound to be some frequencies that are much more damaging than others. The car the body, head and the helmet seem to move out of phase. This will amplify the stress and accelerations in the body immensely.

Do we know which G sensor they use? If it is in the car then it misses the car to body interaction. The earpiece sensor would be better but would miss the forces on the lower back.

I guess a differential requirement between a helmet an car sensors would be much better in describing the compression and elongation of the body and associated stresses.

In any way I would expect either a frequency dependent requirement or a clever way to include the damping of the body in the equation.

Big Tea
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Joined: Sun Dec 24, 2017 7:57 pm

### Re: 2022 cars 'porpoising' at high speed

Is there any way this 'problem' would tie into the 'exit the car in 3 seconds' rule?
Seeing Hamilton creep out of the car makes me wonder how much faster he could have done it if needed.
I had a back problem one time and I know I could not have rushed even if my seat was on fire.
When arguing with a fool, be sure the other person is not doing the same thing.

n_anirudh
n_anirudh
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### Re: 2022 cars 'porpoising' at high speed

Edax wrote:
Sat Jul 02, 2022 10:01 am
continuum16 wrote:
Fri Jul 01, 2022 6:26 pm
An article from motorsport.com has a better breakdown of the equation.
https://www.motorsport.com/f1/news/the- ... /10331177/
https://cdn-3.motorsport.com/images/mgl ... tric-1.jpg
....
I am surprised by the simplicity of this equation.

If I look at the footage there is bound to be some frequencies that are much more damaging than others. The car the body, head and the helmet seem to move out of phase. This will amplify the stress and accelerations in the body immensely.

Do we know which G sensor they use? If it is in the car then it misses the car to body interaction. The earpiece sensor would be better but would miss the forces on the lower back.

I guess a differential requirement between a helmet an car sensors would be much better in describing the compression and elongation of the body and associated stresses.

In any way I would expect either a frequency dependent requirement or a clever way to include the damping of the body in the equation.
What is N_{loop} or rect_{loop}? I dont understand where or how the "-3" comes in, Also can someone explain as to why this is averaged over distance. Isnt peak loads what we are looking for?

JordanMugen
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Joined: Wed Oct 17, 2018 12:36 pm

### Re: 2022 cars 'porpoising' at high speed

continuum16 wrote:
Fri Jul 01, 2022 6:26 pm
An article from motorsport.com has a better breakdown of the equation.
https://www.motorsport.com/f1/news/the- ... /10331177/
The metric seems to be based on kinetic energy and work but I'm a little too thick to understand the exact derivation right this moment, lol.

It doesn't say what the summation is over (presumably N_loop), what x is, or what rect_loop is? It doesn't matter what the time spacing between those N_loop number of values is, just that they are covered by a time period of Δ_t?

Edit -- Oh, ok. In the brackets there is time * (acceleration IF acceleration > 3g), which gives units of s*m/s^2, which gives m/s. Then this is all squared, which gives m^2/s^s or the units of v^2.

Kinetic energy is 1/2 * m * v^2.

So 1/2 appears in the AOM metric, but mass is missing so kg is divided out of the units of AOM, giving units of J/kg to start with. Then the multiplication factor 100 / (distance in km) is applied which gives the equivalence per 100km, i.e., if this happened over d=10km, then multiplying by 100/d means it would happen 10 times that over 100km, giving AOM its final units of J/kg/100km.

Ok, that makes sense.

n_anirudh wrote:
Sat Jul 02, 2022 1:14 pm
What is N_{loop} or rect_{loop}? I dont understand where or how the "-3" comes in, Also can someone explain as to why this is averaged over distance. Isnt peak loads what we are looking for?
It seems redundant, they both subtract 3 but then give all the values less than 3 a multiplication coefficient of zero as well. I guess they are using 3g as the mean acceptable acceleration, and they don't want it to cloud the final metric hence subtracting that level of acceleration away from contributing to the metric?

Edit -- I think that | x | is meant to be | g_(vert etc.) | as otherwise it doesn't make sense.

Edax wrote:
Sat Jul 02, 2022 10:01 am
I am surprised by the simplicity of this equation.

If I look at the footage there is bound to be some frequencies that are much more damaging than others.
Yes, the metric is very much a Fourier transform free zone, lol!

It seems they are going for a simple time- and distance-averaged kinetic energy average of only when g exceeds 3g and that's all.

TLDR: The FIA directive for porpoising/bouncing puts a limit on accelerations over 3G.
Last edited by JordanMugen on Sat Jul 02, 2022 2:29 pm, edited 1 time in total.

n_anirudh
n_anirudh
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### Re: 2022 cars 'porpoising' at high speed

I see that you typed as you worked it out!
I did do a dimensional analysis and the RHS was 1/[L]* [LT^-1]^2 which works out to be [LT^-2] == acceleration
Joule/kg/km is the same as acceleration - just fancy or a bit more practical.

again choosing "3g" is a magic number and perhaps arbitrary, and maybe FIA know best. rect_3g is a step function and if the acc is less that 3g, the metric goes to zero

Not sure why 100km is a standard, again, but yeah, its a round number...

Also noticed that it is d_AOM is measured on specific distances on the track; which effectively mean DRS zones, unless there is high speed corner porpoising(Edit: there is some from what I have seen at Silverstone)?

There are 2 parts to this:
1. Peak loads and not an "averaged" load needs to be considered
2. Frequency of the oscillation (a low level but frequent oscillation could be worse too), so a Strouhal number type metric is missing in my opinion

Xwang
Xwang
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Joined: Sun Dec 02, 2012 10:12 am

### Re: 2022 cars 'porpoising' at high speed

I do not know if you had already discussed about this other aspect of the new directive:
https://the-race.com/formula-1/how-f1s- ... ed-detail/
It seems that FIA will have a better look on flexibility of the bottom side of cars.
Indeed I had thought that if the area where the plank is attached is made like rubber, it could be possible to run always with the plank touching the ground by damping in that way the porpoising.
Is there any team that uses this trick?
I think one could be Red Bull because they are always creating sparks in a stable manner while others are bouncing like kangooros, but maybe I am wrong.
I'm still learning English so please excuse me if my English is not good enough and feel free to correct me via PM if you want.

Just_a_fan
Just_a_fan
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### Re: 2022 cars 'porpoising' at high speed

Xwang wrote:
Sat Jul 02, 2022 2:52 pm
I do not know if you had already discussed about this other aspect of the new directive:
https://the-race.com/formula-1/how-f1s- ... ed-detail/
It seems that FIA will have a better look on flexibility of the bottom side of cars.
Indeed I had thought that if the area where the plank is attached is made like rubber, it could be possible to run always with the plank touching the ground by damping in that way the porpoising.
Is there any team that uses this trick?
I think one could be Red Bull because they are always creating sparks in a stable manner while others are bouncing like kangooros, but maybe I am wrong.
If it's being done on purpose and is contrary to the rules then it should be stamped upon by the FIA. They just have to be able to prove wrong doing on the part of any team suspected of breaking the rules. Perhaps we will see another example of a "secret agreement" between a team and the FIA...
Turbo says "Dumpster sounds so much more classy. It's the diamond of the cesspools." oh, and "The Dutch fans are drunk. Maybe"

Xwang
Xwang
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Joined: Sun Dec 02, 2012 10:12 am

### Re: 2022 cars 'porpoising' at high speed

Just_a_fan wrote:
Sat Jul 02, 2022 9:48 pm
Xwang wrote:
Sat Jul 02, 2022 2:52 pm
I do not know if you had already discussed about this other aspect of the new directive:
https://the-race.com/formula-1/how-f1s- ... ed-detail/
It seems that FIA will have a better look on flexibility of the bottom side of cars.
Indeed I had thought that if the area where the plank is attached is made like rubber, it could be possible to run always with the plank touching the ground by damping in that way the porpoising.
Is there any team that uses this trick?
I think one could be Red Bull because they are always creating sparks in a stable manner while others are bouncing like kangooros, but maybe I am wrong.
If it's being done on purpose and is contrary to the rules then it should be stamped upon by the FIA. They just have to be able to prove wrong doing on the part of any team suspected of breaking the rules. Perhaps we will see another example of a "secret agreement" between a team and the FIA...
If what is written is correct and if I have correctly understood that, the new directive clarifies that the 2mm of maximum deflection applies to the whole area and not just to the front and rear part of the plank that is where the test was conducted up to now.
I'm still learning English so please excuse me if my English is not good enough and feel free to correct me via PM if you want.

siskue2005
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Joined: Fri May 11, 2007 8:50 pm

### Re: 2022 cars 'porpoising' at high speed

https://the-race.com/formula-1/how-f1s- ... ed-detail/

he FIA notes that any car configured around a plank which flexes by more than the 2mm regulation limit will be considered in contravention of regulations 3.5.9e and 3.15.8a. Those regs state:

“3.5.9e. The thickness of the plank assembly measured normal to the lower surface must be 10mm ± 0.2mm and must be uniform when new. A minimum thickness of 9mm will be accepted due to wear, and conformity to this provision will be checked at the peripheries of the designated holes.

“3.15.8a. Bodywork within RV-PLANK may deflect no more than 2mm at the two holes in the plank at XF=1080 and no more than 2mm at the rearmost hole, when the car, without driver, is supported at these positions. The car will be supported on 70mm diameter pads, centred on the holes, and only in contact with the underside of the plank assembly. The displacement will be measured at the supports, relative to the reference plane at the centre of each hole.”

Big Tea
91
Joined: Sun Dec 24, 2017 7:57 pm

### Re: 2022 cars 'porpoising' at high speed

Now are we going to run into 'the letter of the law' area here as 'Flex' is not 'deflect' and they have a spring on it?
When arguing with a fool, be sure the other person is not doing the same thing.

Zynerji
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Joined: Wed Jan 27, 2016 3:14 pm

### Re: 2022 cars 'porpoising' at high speed

I feel this should be handled by the GPDA than the FIA. I mean, if protection from abuse for the drivers that are forced to endure for performance readons isn't exactly what it's there for, you might as well roll it up.

Just_a_fan
Just_a_fan
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### Re: 2022 cars 'porpoising' at high speed

Zynerji wrote:
Sat Jul 02, 2022 10:20 pm
I feel this should be handled by the GPDA than the FIA. I mean, if protection from abuse for the drivers that are forced to endure for performance readons isn't exactly what it's there for, you might as well roll it up.
Rules shouldn't be set or policed by the competitors, be that the teams or the drivers. The FIA should set the rules and police them. If it can't do that, then it should employ someone who can. Too many of the problems and issues over the years have been caused by the teams having too much say in the rules and how they're enforced.

A good thing for the new FIA President to do would be to create a system that puts the power fully back in the hands of the FIA. He's played around with rules on underwear and jewellery - how about creating a rule book that is consistent and enforceable and then actually enforcing it properly and entirely fairly.
Turbo says "Dumpster sounds so much more classy. It's the diamond of the cesspools." oh, and "The Dutch fans are drunk. Maybe"