Rear wing flex and FIA regulatory test 2021

[henry]

Bodywork swell, In the FIA technical regulations 3.9 this is described ,with maximum limits. So if bodywork swells more , it is in fact illegal. I don’t think a team will take that risk.

As far as I can tell the load tests in 3.9 are defined for front and rear wings and the floor, but I can’t see anything for engine covers other than a general requirement in 3.8b to be rigid.

[hugobos]

I stand corrected thank you

[dans79]

There were many arguments as to why DAS was illegal according to the regulations last year, but the rules were not changed until end of season (even though Mercedes allegedly ran with it disengaged at times towards the end of the season); why is this different?

For flexing wings the rules don't need to be changed, as a catch all rule that covers this specific scenario, already exists.

here are the current technical regulations.
https://www.fia.com/sites/default/files ... -03-05.pdf

3.9.9

In order to ensure that the requirements of Article 3.8 are respected, the FIA reserves the
right to introduce further load/deflection tests on any part of the bodywork which appears to
be (or is suspected of), moving whilst the car is in motion.

here is 3.8 and the highlighted part 3.9.9 is referring to (imo)

With the exception of the parts described in Articles 11.4, 11.5 and 11.6, and the rear view
mirrors described in Article 14.3, any specific part of the car influencing its aerodynamic
performance:

a. Must comply with the rules relating to bodywork.

b. Must be rigidly secured to the entirely sprung part of the car (rigidly secured means
not having any degree of freedom).

With the exception of the driver adjustable bodywork described in Article 3.6.8 (in addition to
minimal parts solely associated with its actuation) and the parts described in Articles 11.4,
11.5 and 11.6, any specific part of the car influencing its aerodynamic performance must
remain immobile in relation to the sprung part of the car.

Any device or construction that is designed to bridge the gap between the sprung part of the
car and the ground is prohibited under all circumstances.

No part having an aerodynamic influence and no part of the bodywork, with the exception of
the parts referred to in Articles 3.7.11, 3.7.12 and 3.7.13, may under any circumstances be
located below the reference plane.

With the exception of the parts necessary for the adjustment described in Article 3.6.8, any
car system, device or procedure which uses driver movement as a means of altering the
aerodynamic characteristics of the car is prohibited.

If the FIA thinks teams are violating 3.8b and gaining an advantage, they can invoke 3.9.9 and create new tests. Thus, the rules don't need to be changed because as they exist now, the fIA can ensure almost anything can be made illegal.


DAS wasn't illegal, because no rule specifically exclude it. Another thing that a lot of people don't know is that the FIA knew about DAS before it was ever used on track, and gave it the ok.

https://www.racefans.net/2020/07/04/ana ... -is-legal/

However we know they engaged with the FIA at an early stage in the design process. Technical director James Allison recently explained how the team raised the DAS concept with the FIA a year ago.
In that early incarnation, DAS was operated not by sliding the steering wheel forwards and back as onboard cameras revealed in February and showed again in practice yesterday. Instead, as Allison, described a separate lever was originally used to achieve the adjustments in toe angle DAS allows.

“They begrudgingly agreed the dual axis steering was actually legal,” Allison recalled of their dealings with the FIA. “But they didn’t much like the way we’d done it because the second axis we were getting from a lever on the wheel rather than that whole wheel movement. They said ‘no, you’re going to have to move the whole wheel in and out’.

“I think when they said that, they were hoping that would be too difficult and that we would go and cause them no more problems.”

That didn’t happen. Mercedes built DAS using the ingeniously simple and satisfyingly lateral solution of sliding the steering wheel back and forth. And more trouble followed when Red Bull objected to it.

It's kind of hard to make something illegal, when you don't have a rule in place already, and you told a competitor it's legal if you do it this way.

[RaceFan1]

There's been talk of the flexing rear wing and body work swell aiding cars straight line speed but, how about excessive shark fin flex? Mercedes is too detail oriented to leave this very flexible shark fin on the car if it weren't providing an advantage. Can the amount of flex in this piece of bodywork be aiding the Mercs more than a flexing rear wing at speed?

[Stu]

There's been talk of the flexing rear wing and body work swell aiding cars straight line speed but, how about excessive shark fin flex? Mercedes is too detail oriented to leave this very flexible shark fin on the car if it weren't providing an advantage. Can the amount of flex in this piece of bodywork be aiding the Mercs more than a flexing rear wing at speed?

I keep mentioning this. In combination with T-wing flex it probably has the same/similar overall effect as the flexing/reduced AoA rear wing - reducing load and drag on the rear of the car when DRS is not in operation.
I’d like to see a comparison of the RB wing at the same speed as the video that is doing the rounds but with the DRS open.
If the flexing shark fin and T-wing were harmful/not beneficial it WOULD be engineered out. The Mercedes has the most flex in these items of any team.

[SmallSoldier]

There's been talk of the flexing rear wing and body work swell aiding cars straight line speed but, how about excessive shark fin flex? Mercedes is too detail oriented to leave this very flexible shark fin on the car if it weren't providing an advantage. Can the amount of flex in this piece of bodywork be aiding the Mercs more than a flexing rear wing at speed?

I keep mentioning this. In combination with T-wing flex it probably has the same/similar overall effect as the flexing/reduced AoA rear wing - reducing load and drag on the rear of the car when DRS is not in operation.
I’d like to see a comparison of the RB wing at the same speed as the video that is doing the rounds but with the DRS open.
If the flexing shark fin and T-wing were harmful/not beneficial it WOULD be engineered out. The Mercedes has the most flex in these items of any team.

I don’t think that the T-Wing helps with drag, it actually adds drag... If not, the teams would be using them in tracks where more top speed (less drag) is required... The T-Wing adds downforce at the expense of the additional drag.

The other interesting thing to note is that the Shark Fin isn’t “Flexing”, it is oscillating and the reason why you see more of it compared to for example the Red Bull is because it has a larger span (the shark fin in the mercedes car is larger), therefore with a larger area of a very slim panel, it is expected to oscillate due to wind and vortices upstream


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[RZS10]

And those two parts have nothing to do with the rear wing flex ...

I do wonder however how the cars with similarly sized shark fins compare, that would be the Ferrari, Haas and maaaaybe the Aston (judging by the latest pics in the car comparison thread https://s3.gifyu.com/images/image206df4df25c2146e.png) - all the other teams will have less wobble in that part simply because theirs are a lot smaller.

From a short look at the (unfortunately low res) Ferrari footage their T-wing and fin also move a lot, can't find videos of the other cars.

Maybe the simple answer is that any drawback from those flappy fins on the big finned cars isn't large enough (or maybe even negligible) to justify any additional material that high up.

It's a bold assumption that this could have the same quantifiable advantage as reducing the AOA on the rear wing by a few degrees, but maybe it should be discussed in a seperate "Bodywork parts flexing" thread because the "but this part does this" and "but this team does that" posts don't contribute to the matter at hand, no?

[zibby43]

There's been talk of the flexing rear wing and body work swell aiding cars straight line speed but, how about excessive shark fin flex? Mercedes is too detail oriented to leave this very flexible shark fin on the car if it weren't providing an advantage. Can the amount of flex in this piece of bodywork be aiding the Mercs more than a flexing rear wing at speed?

I keep mentioning this. In combination with T-wing flex it probably has the same/similar overall effect as the flexing/reduced AoA rear wing - reducing load and drag on the rear of the car when DRS is not in operation.

Disagree with that assessment. The very presence of a t-wing in and of itself adds net drag - however, very little. The t-wing acts as additional downforce (which is why it usually only appears on medium and high-downforce circuits).

Because of its high aspect ratio (ratio of span:chord), it is very efficient (downforce provided nearly offsets drag induced).

With t-wings, you actually want the *least* amount of aeroelasticity as possible, as it ruins the performance of these highly efficient tools. And although they are efficient, the amount of actual raw performance they add is negligible (because they're just so small, especially in comparison to the rear wing). But because of the efficiency component, they’re worth utilizing.

A slight amount of upwash from the t-wing may interact with the rear wing, but it’s not a flow conditioner. That’s what the shark fin is there for (source of laminar flow stream to the RW).

Also provides stability in yaw conditions. In sum, both of these devices have benefits, but none of them connect with the RW, and their overall footprint on car performance is so small relative to the RW that even though they should be discussed in a separate thread, it’s probably not worth it.

[BrunoH]

could be yeah.
i was always more under the impression that because they have more rake, they can go with softer suspension, hence when downforce increased the car wold lower more at the back.
but yes seems its flexing a bit more

[PlatinumZealot]

Nice technical piece from Matt Somerfield on RB's "flapping phenomenon"

https://au.motorsport.com/f1/news/flapp ... e/6507247/

Excerpts:

"The new rotational tests will prevent the wing from ‘steering’ around the centre plane, a trick that the FIA may be focusing on as being used to circumvent the symmetrical loading applied in the deflection tests.

This is a notable feature in the onboard footage from the rear facing T-camera of the Red Bull, for example.

Close examination of the moving images shows the top rear wing element ‘flapping’ laterally, moving side-to-side with the relative vibration of the endplates, which owing to their design also find themselves oscillating.

This could explain how the wing ‘bends’ rearwards under load, as the wing pivots around the central axis, with one side of the wing moving incrementally rearward before the other."

Also, the 3-race grace period may be irrelevant, as rival teams could choose to simply protest wings that they believe fall afoul of the rules.

"It will be interesting to see if the new load/deformation tests have an impact on the competitive order when we head to the long straights at Paul Ricard.

Any team making changes to its wings, to ensure they comply to the rules, will also need to juggle the potential consequences that could have on them hitting the budget cap limit.

There could also be intrigue beforehand though, because teams could yet decide to lodge protests against their rivals should they believe they’re using a rear wing assembly that contravenes the current regulations, even before the new tests come in to force."

He takes many ideas from here. For the rest of the world its OK i guess. But for F1 tech its pretty much giving us regurgitated food.
I was the first to mention the wing twisting and assymmetrical bending. What does Matt know of that? Lol. But anyway as I said it is good for the wider readership that he gives insights.

[PlatinumZealot]

could be yeah.
i was always more under the impression that because they have more rake, they can go with softer suspension, hence when downforce increased the car wold lower more at the back.
but yes seems its flexing a bit more

It seems?
A bit more?




Suspension and car movement does not change the fact that the rear wing deflects signficantly relatively to the fixed, rigid mounting point that is the roll hoop.

In fact this bending wing is barely legal! <Edit, that was a bit too much, PZ>

[Big Tea]

Is the T wing an actual wing with downforce, or is it a vane to direct air? I was wondering if in conjunction with that, the waving shark fin would create a low pressure area beneath the rear wing?

[hollus]

Slightly off topic questions:

Was Red Bull's having this level of deflection in the last high downforce race of 2020? Does Alpha Tauri's rear wing have anything similar?
Or is it really a new development (the extreme degree of flexing) for Red Bull in 2021?

[SmallSoldier]

Slightly off topic questions:

Was Red Bull's having this level of deflection in the last high downforce race of 2020? Does Alpha Tauri's rear wing have anything similar?
Or is it really a new development (the extreme degree of flexing) for Red Bull in 2021?

Red Bull had a similar degree of flexing at Austria in 2020 for sure.

I haven’t found footage of the Alpha Tauri rear wing


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[RZS10]

If you find any additional footage please drop it in here and i'll throw a gif into photoshop in order to add it to the comparison