Rear wing flex and FIA regulatory test 2021

[Big Tea]

What kind of benefit do you expect from a sideways wobbling rear wing?

just a 'passing thought' but what effect would the disrupted air from that have on a following (or passing) car?

Not as much as the outwash from the front wing/barge-board combo (the air from the wing is moving upwards as it is). At these super low speeds (where the cars do not run on-track) the effect would be zero. It does suggest that the structure of the wing is designed to operate in the loaded state, rather than unloaded (this phenomenon is largely unnoticeable during running - except for in super-slow-mo shots over kerbs - a lateral force rather than longitudinal).

Much noise has been made about the RB upper element flapping during practice in Brazil, this looks to have been caused by a DRS mechanical failure, during scrutineering checks if this caused the flap to exceed the 85mm permitted gap it would have lead to a DSQ (as suffered by Mercedes).
When the DRS is open the top flap still generates downforce, the pivot locations are closely controlled (at the rear edge of the flap), making it physically impossible for the airflow to over-open the slot gap from that mechanically allowed by the mechanism.

What is interesting this weekend is that we are seeing what Red Bull were going to the stewards about last week. They actually believe that Mercedes are flexing the rear of the lower element (this is not a tested item during the load tests as far as can find). If (potentially a big if!) this is what Mercedes are doing, then hats off to them, a great play and obviously something that Red Bull have also looked at but not dare race!!

If the gauge is pushed between the moving and non moving element does it not by definition check both?
If the lower surface deflects the gauge goes in and fails the measurement.
Admittedly if it is checked from the rearwards so could be pivoted at that end, but this would still leave a restriction thee whatever the 'other end' does.

[Stu]

just a 'passing thought' but what effect would the disrupted air from that have on a following (or passing) car?

Not as much as the outwash from the front wing/barge-board combo (the air from the wing is moving upwards as it is). At these super low speeds (where the cars do not run on-track) the effect would be zero. It does suggest that the structure of the wing is designed to operate in the loaded state, rather than unloaded (this phenomenon is largely unnoticeable during running - except for in super-slow-mo shots over kerbs - a lateral force rather than longitudinal).

Much noise has been made about the RB upper element flapping during practice in Brazil, this looks to have been caused by a DRS mechanical failure, during scrutineering checks if this caused the flap to exceed the 85mm permitted gap it would have lead to a DSQ (as suffered by Mercedes).
When the DRS is open the top flap still generates downforce, the pivot locations are closely controlled (at the rear edge of the flap), making it physically impossible for the airflow to over-open the slot gap from that mechanically allowed by the mechanism.

What is interesting this weekend is that we are seeing what Red Bull were going to the stewards about last week. They actually believe that Mercedes are flexing the rear of the lower element (this is not a tested item during the load tests as far as can find). If (potentially a big if!) this is what Mercedes are doing, then hats off to them, a great play and obviously something that Red Bull have also looked at but not dare race!!

If the gauge is pushed between the moving and non moving element does it not by definition check both?
If the lower surface deflects the gauge goes in and fails the measurement.
Admittedly if it is checked from the rearwards so could be pivoted at that end, but this would still leave a restriction thee whatever the 'other end' does.

That would all depend on how much force is required to bend the rear of the lower element. If there is a flexibility test on the lower element (not sure, cannot find it, but it would make sense if there were!) it would be in excess of 10N (which is not a huge amount of force in itself).
All measurements (whether static dimensional tests or dynamic force tests) have to be done relative to some fixed point/plane. It would be really interesting to see how to maximise performance by taking each to the limit.
Aero-elasticity is something that all teams try to take advantage of, while at the same time complying with the dynamic tests performed to ‘prove’ obeyance. You only need to look at the front wings for that, the main-plane IS tested dynamically, the other elements are not, these twist quite dramatically on track (they are by the written regulation illegal), and are definitely moving in relation to the sprung part of the car, however, because they are not subjected to any dynamic testing by scrutineers they are considered as legal. ALL teams are doing this. Interestingly, itshould be more difficult to work them in this way next season because the mounting method of the front wings is being changed).

[west52keep64]

Interesting analysis by Di Resta here:

https://www.skysports.com/watch/video/s ... -rear-wing

Basically, there's no evidence of movement of the wing from the onboard video. He shows a close up showing the "score marks", but there's nothing to suggests these are a result of the wing flexing.

I don't actually think there's anything in this latest claim of wing flexing on the Mercedes. Perhaps it's some clever misdirection by Mercedes? A bit like when Red Bull used fake exhaust stickers.

EDIT: Here's a still of the score marks:

[jjn9128]

Interesting analysis by Di Resta here:

https://www.skysports.com/watch/video/s ... -rear-wing

Basically, there's no evidence of movement of the wing from the onboard video. He shows a close up showing the "score marks", but there's nothing to suggests these are a result of the wing flexing.

I don't actually think there's anything in this latest claim of wing flexing on the Mercedes. Perhaps it's some clever misdirection by Mercedes? A bit like when Red Bull used fake exhaust stickers.

EDIT: Here's a still of the score marks:

https://i.imgur.com/yLQSyQF.png

Not that interesting at all, in fact it highlights a complete ignorance of even basic aerodynamic principals. When the DRS is open the rear wing loading drops, even on the mainplane, so the flex (which is presumably caused by -ve pressure) wouldn't happen. Also Wolff's "we've passed the tests" rather than a flat out denial suggests Merc are up to something.

[west52keep64]

Not that interesting at all, in fact it highlights a complete ignorance of even basic aerodynamic principals. When the DRS is open the rear wing loading drops, even on the mainplane, so the flex (which is presumably caused by -ve pressure) wouldn't happen. Also Wolff's "we've passed the tests" rather than a flat out denial suggests Merc are up to something.

Do you have any picture or video to show that? I've seen zero evidence so far. If it's so obvious and blatant, why is it so hard to find a shred of evidence of this happening? These "score marks" don't really show anything, it could just be dirt showing some flow separation on the main plane.

[PhillipM]

Also Wolff's "we've passed the tests" rather than a flat out denial suggests Merc are up to something.

I would also flat out deny if even if there was nothing there because it keeps other teams looking and wasting time on nothing...

[Sieper]

Here is another videoanalysis, with purple reference to show the lowest point the main plane reaches (it even dips a bit below that) and look how far it moves up under braking.

[dans79]

Here is another videoanalysis, with purple reference to show the lowest point the main plane reaches (it even dips a bit below that) and look how far it moves up under braking.

as I mentioned in the other thread where you also posted this.

That's the entire wing rotating backwards, not the main plane flexing in isolation! Draw another reference line at the top of the DRS flap, and you will see that it changes in parallel. What you are seeing is the entire rear wing rotating backwards, thus why you can see the gap!

[bonjon1979]

Here is another videoanalysis, with purple reference to show the lowest point the main plane reaches (it even dips a bit below that) and look how far it moves up under braking.

as I mentioned in the other thread where you also posted this.

That's the entire wing rotating backwards, not the main plane flexing in isolation! Draw another reference line at the top of the DRS flap, and you will see that it changes in parallel. What you are seeing is the entire rear wing rotating backwards, thus why you can see the gap!

Exactly, and you'll see the same on all the other cars in the braking zone.

[west52keep64]

Agreed, this is really the same observation made earlier in the year, but now just drawing the reference line in a different place.

We're still seeing no evidence of significant movement of the trailing edge of the rear wing mainplane, definately not to the level being suggested by Red Bull. I do hope Red Bull release all the evidence they have, even if after the season, surely there's no reason not to?

[Stu]

Red Bulls ‘evidence’ is most likely…
a) We know this is structurally possible (we have designed our own variant and modelled the structure to pass the current load test AND still flex as we suggest the Mercedes is)
b) We know the aerodynamic effect of doing this (we have designed our own variant and modelled the aerodynamic effect which shows HOW the Mercedes is able to achieve the speed increase)

[Just_a_fan]

Red Bulls ‘evidence’ is most likely…
a) We know this is structurally possible (we have designed our own variant and modelled the structure to pass the current load test AND still flex as we suggest the Mercedes is)
b) We know the aerodynamic effect of doing this (we have designed our own variant and modelled the aerodynamic effect which shows HOW the Mercedes is able to achieve the speed increase)

Or they have no evidence at all but are just trying to mess with Mercedes - get the FIA looking at the car, disrupting the weekend, that type of thing.

If RedBull actually had evidence that the car was illegal, they'd have handed it to the FIA and thrown it to the media pack to chase.

[OO7]

Red Bulls ‘evidence’ is most likely…
a) We know this is structurally possible (we have designed our own variant and modelled the structure to pass the current load test AND still flex as we suggest the Mercedes is)

That's still legal though right. I don't know what the tech regs/TDs say about he fiducial markers on the rear wing however.

[Just_a_fan]

Red Bulls ‘evidence’ is most likely…
a) We know this is structurally possible (we have designed our own variant and modelled the structure to pass the current load test AND still flex as we suggest the Mercedes is)

That's still legal though right. I don't know what the tech regs/TDs say about he fiducial markers on the rear wing however.

That's the thing - if it passes the test then they can race it. That's the argument that Red Bull themselves used with their own wing - "it passes the test". If Red Bull think they have evidence of wrong doing, bringing it up after the event won't help them - the FIA won't design a new test after the final race and apply it retrospectively.

Maybe Red Bull are going to drop the bomb if Hamilton wins in Jeddha. Making Mercedes change the car for the last race would be one way of throwing them a curve ball.

[WaikeCU]

I still don't get why we are looking at a video of Paul Ricard from months ago?

I mean we can look at the Spanish GP as well

Start/Finish straight:


Into T1:


Comparison top rear wing vs top edge of the fin

Also notice the suspension arm vs rear wing endplate in comparison of top speed and cornering speed

cfr. Di Resta analysis of Mercedes suspension clever trick in Turkey. It's not new!