Flexible wings 2011

[N12ck]

I have found this and it may be of interest :

http://mccabism.blogspot.com/2011/04/ho ... -wing.html

[malcolm]

Electrical connection made when wing is attached? Switch on a hydraulic line thrown? Moving sockets in the tub? What mechanism would you need to make the wing go limp once its plugged onto the chassis?

Sounding a bit Rube Goldberg though!

Or rubber washers?

Laws of physics -> moot since the RB7 isn't squatting on the straights. It may squat for rear grip coming out of corners, but that's the low speed damping. At high speed, the damping can be much stiffer so the rake is preserved (since I think this is a big part of the flexi-wing puzzle).

Sorry Lindz, you're a bit mixed up there. High and low-speed damping refer to damper piston speeds, not the speed of the car. High speed damping controls spring motion over sudden increases or decreases in force applied to the wheel and tire (cracks, dips, bumps, kerbs, etc). Low speed damping controls spring motion over gradual increases and decreases in force (turn-in, corner exit, braking, etc).

Therefore, the shocks would have little to no control of the ride-height of the car over a long straight, unless they have some sort of variable gas-pressure system that augments the spring... but that would be active suspension and obviously illegal for reasons other than the aero rules we've all been beating to death.

As i have no slightly clue about advanced composite layering technologies, i will venture this solution:



Built-in eliptical carbon tube 800mm from front wheel center line, firmly attached to end plates.
will it work ?

*standing ovation*

Like you, my composite knowledge is limited, but it seems like you could definitely be on the right track. Why has no-one replied to this, and instead just bleated on about rules? Yay? Nay? Maybe-sorta?

2) It seems the 2011 RB front wing is tilting toward the front of the wing. The end plates are not sealing that well with the rear half of the end plate still well off the ground. Is this the case that some sealing improvement is better than nothing or is there a benefit from the rake varying with speed/down-force?

First, getting a wing closer to the ground dramatically improves its effectiveness... so even ignoring the endplates altogether, it will generate more downforce.

Second, the front part of the endplate is considerably more important than the rear; if you look at the velocity profile of air moving under a wing, you will see that air speed is very high around the leading edge to the lowest point of the wing, and then it drops off from there (with little jumps wherever there is a slot-gap to energize the flow). The other elements hardly provide any downforce, they just drive the main-plane of the wing by sucking more air under it. Therefore, the back of the wing matters very little, and the front of the wing matters a lot... which means that if the wing tilts forward, it will give greater sealing where it needs it and gives up sealing where it doesn't need it.







About the rules: I've said my piece and others said the same more eloquently than I, so I have nothing more to say beyond that the RB7 passes one rule, but breaks another. It's pretty simple.

[BreezyRacer]

I have found this and it may be of interest :

http://mccabism.blogspot.com/2011/04/ho ... -wing.html

Hi Gordon. Indeed a very interesting article, particularly as it relates to advances in CFD, getting ever closer to real life interactions. Implications .. as always, important things get more detailed and more complex.

[bot6]

I thought I mentioned a similar theory to Marekk's for how the bendy wing works, but it must have been on the RB7 thread and not here.

I think indeed the principle of the bending wing is just that: a reinforcement aligned with the testing point, used as a pivot (or "neutral axis" for those who like structural engineering) in the bending of the wing with the offset aero center of pressure making the wing twist and bend at the same time.

So pretty much what his picture shows, but not quite a rod as a separate piece going through the wing, rather a built in reinforcement in the laminate. Same principle, but a bit more refined in the execution.

That, of course, added to the setup rake and the bending of the nose outer structure and the nose pillars attached to said structure.

It's really the whole car working to lower that wing, not just the wing itself. At least on the RB7. The McLaren wing seems to use the bend/twist coupling in the same way, but the nose and pillars don't bend down. So it's closer in principle to the RB6 wing.

[malcolm]

An idea that is similar to a few others, perhaps with more detail than I recall reading:

The nose is rather stiff. It may flex a small amount, but not much at all. It bolts to a flexible section of the bodywork rather than bolting to the actual solid tub itself (perhaps the nose could loosely locate to the tub with pins for crashworthiness).

This would allow the nose to be sufficiently stiff to pass the static tests alone, off the car; however it is actually the 30-50 cm of bodywork behind where the nose bolts on that flexes a few millimeters to allow the rigid nose-cone to move several more since it extends further forward (centre of rotation would be somewhere around a metre or so back from where the nose bolts on, allowing a small bodywork flex to have a larger effect on the movement of the nose). This would also ensure that there is never a gap between the nose and the bodywork behind it, thus keeping people focused on the wing rather than the bodywork over the chassis.

Of course, it wouldn't need to flex much either, since the wing itself is at the very limit of the flexure allowed by the current testing. Either by itself would have a minimal effect, but the combination of the semi-flexible wing and the semi-flexible bodywork results in a wing that's almost scraping the ground and making awesome downforce.

...but good ole Charlie would have thought of that last year, right?

[PlatinumZealot]

I have found this and it may be of interest :

http://mccabism.blogspot.com/2011/04/ho ... -wing.html

Interesting indeed but all the teams have been using multi-physics for years. The regular joe can use multiphysics too, so I think what redbull is doing is way more sneakier than how they use their software.

[bot6]

I think they did think of it, which is why this year the noses have to be homologated (so crash-tested).

They thought that by making it compulsory to have the nose double up as a crash structure, it would have to be stiff.

They did not account for Red Bull to pull a "double-chassis" on them: hard core inside, bendy shell outside holding the wing pillars.

[malcolm]

Sorry, maybe I wasn't clear. More simply put: perhaps the Red Bull has a rigid nose, but the bodywork, behind it (around the monocoque) flexes. This allows the nose to move while the nose-cone itself remains stiff, since the nose-cone bolts to the bodywork rather than the chassis itself. Same "double-chassis" principle, but applied behind the nose-cone, rather than to the nose-cone.

That would explain why the nose is so close to the ground while it passes the tests with flying colours, since the actual part that flexes the most is never tested. The wing flexes a bit, but not much more than the other teams, if at all. It's the combo of the mildly flexible wing and the much more flexible body around where the suspension mounts that allows the wing to ride low.

[bot6]

I see what you mean now. I think it's more the outer shell of the nose that flexes rather than the front bodywork around the tub. The photographic evidence seems to suggest this is what's happening, and it would also be much easier to design and make.

[malcolm]

Yeah, it's easier to make a rigid chassis and a flexible outer nose-cone; however, that doesn't explain why the nose itself passes all of the tests when it's off the car, yet flexes on the car on track.

[Lindz]

Malcolm, in addition to my mind going a mile a minute and confusing high and low speed damping with velocity of the car (what a rookie mistake!), I also didn't clarify that I was talking about the 3rd damper/heave spring/whatever certain teams call it. You're talking about roll damping (and are 100% correct) but that is separate than the heave control. So the roll damping (individual L/R dampers) doesn't affect the heave damping too much.

So let me rewrite my observation with (hopefully) less mistakes: It appears that the heave control is pretty stiff on the RB7, since the car doesn't squat much during acceleration and it retains most of it's rake down the straight. Last year, the RB6 was so good because of the balance the team had with their suspension tuning. This year the RB7 appears to have kept the magic. It's not just the ability to ride kerbs and put power down... this is Adrian Newey we are talking about here... the suspension has a direct link to the aerodynamic design of his cars.


BTW, what's up man? You never told me you come on F1Technical also!

[McG]

How can they get away with it? It's clear that it flexes.

Why do bigger teams get innovations banned, less expensive in some cases, but these smaller teams are left to it. Is it for the fairytale story?

[malcolm]

Ok, I see what you mean now. With isolating roll and heave, they've figured out how to keep the rake with stiff heave, while allowing the back end to almost flop around with a low roll stiffness (or actually flop around, in the case of Webber in practice in Korea). This keeps the mechanical balance of the car, despite having crazy rear heave stiffness since it's compensated by insanely low roll stiffness (which is possible with just the one spring, rather than independent springs for each side and just using the heave spring to augment them).

Then as soon as the wing starts making jam, the front dives, rear stays put, the wing flexes a bit (within legal limits), the nose flexes a bit (within legal limits) and the resultant of all that puts the reference plane into the ground and the wing tips just above the track, and it then turns the entire floor into a diffuser of sorts.






Oh yeah, I signed up a year or two ago to comment on Tomba's development blog, and then when you mentioned this thread the other day on ZT, I came over to check it out. As is usually the case, I couldn't keep my metaphorical mouth shut.

[alelanza]

Surprised this hasn't been posted, tweet via scarbs: http://mccabism.blogspot.com/2011/04/ho ... -wing.html

[outer_bongolia]

Yeah, it's easier to make a rigid chassis and a flexible outer nose-cone; however, that doesn't explain why the nose itself passes all of the tests when it's off the car, yet flexes on the car on track.

If you know exactly what the test is, you can design something that will not bend when certain pressures are applied. I don't think that would be terribly hard for someone with Newey's intelligence and his team.

The thing that I don't understand is why FIA is only sticking to the tests. When Ferrari (was it them?) was using flexible rear wings, FIA just used the racing pictures to tell them to make it more rigid.

Isn't "proving that it flexes during the race" a good way of "proving that it flexes"? Why does it have to fail a very well specified test?