Reducing the drag of a two element wing through stall

[horse]

McLaren must be very confident of the legality of the wing, maybe someone can explain what the difference is between this wing and Ferrari's flexible wing?

^ (Written at the same time as Hollus, here is my ten pence worth:)

In terms of what they achieve they are very similar, but strictly they are not moveable aero as the wings themselves do not move. Personally, if I were the regulator, I might not be keen on them, as an accidental reduction of DF at the wrong time could be dangerous, along with issues with the general stability of the car -> it's still an oddity how this high top end does not translate into an improved lap time. Still, who knows, maybe this is the first safe moveable aero device?

[marcush.]

I'd assume there would be quite a bit of losses if you'd have air going backwards to the front wing and back again?

speaking of losses I don´t think the air does care if it fows against the direction of the system in wich it is contained...there are no rocks and pieces that have a lot of inertia in air? it is more a question of how gentle you could possibly route the ducting through the whole car without creating losses .If that was designed into it from day one I´m sure it cannot be any more complicated than a wiring harness..(oh .sh...wrong example..)

[LoudHoward]

what happens when car is trailing another car on a straight line, with high speed and yanks the steering wheeling hard to left (or right) in his atempt to overtake the car infrong?

At high speed they've got a huge amount of df being produced, a few percentage points reduction isn't going to matter in the example you mentioned. Especially since it won't be an unexpected drop, they've tested with it and know what the car can do, they know in a set configuration in a 3rd gear corner what downforce they're going to get, and they know how much they'll have for flat out kinks on straights.

I imagine they get more caught out by gusts of wind an so forth, these are random to them and no two are the same!

[bonjon1979]

You guy's are forgetting one major thing - a Driver controllable system would be classed as active aero and is therefore banned (the only exception is the front wing)!

Besides, the only way for this to work properly and reliably is if it is tuned for a certain speed like the old bendy rear wings where.

The thing you're forgetting is that cars are scrutinised without the drivers in the car. In scrutineering there will be no active system as the active part in this theory is the driver itself rather than something physical in the car. So if there is no driver in the car, there is no active aero...

BS, the FIA is dumb at times but not that dumb! [-X

It's not about being dumb or not it's what's written in the rules that counts. There is nothing in the regulations that would outlaw this device. Remember that spirit of the rules doesn't mean anything, 'slots' in the floor last year? - as long as there are no moving parts in the system on the car then there is no grounds for it to be banned. However, I doubt the whole driver controlled thing, I suspect that it's a pressure related system, ie at certain speeds it is switched on and off. People have shown examples of how this could work without any movable parts on the previous pages have a read, there's some great stuff there.

[Tbox]

I'm having a very hard time believing this little inlet has anything to do with the rear wing. The most obvious purpose, in my mind, would be that they've got a hot spot within the cockpit that needed some cooling.

Same, it has nothing to do with it, its obviously to cool something else.

+1, this thing is to small to produce an airstream to the rearwing, the airbox channel idea is more likely used...

Read the last few pages. It doesn't channel air for the wing, just air to a fluidics switch, which contains NO moving parts and does not require much flow at all.

[Mysticf1]

Lets not forget that downforce decreases while braking as you bleed off speed.

either way i still don't buy the snorkel theory, seems rather far fetched to me, but hey that's just me, i don't pretend to be an expert.

[Shaddock]

If McLaren remove the snorkel from the car for Monaco then its probably part of a switch. Unless of course they bring the mother of all snorkels, and use it as a constant stream of supplementary air to the rear wing.

[autogyro]

If McLaren remove the snorkel from the car for Monaco then its probably part of a switch. Unless of course they bring the mother of all snorkels, and use it as a constant stream of supplementary air to the rear wing.

Even at Monaco there are straits where a higher top speed would be useful.

[Giblet]

Yes, no matter what, having a wing you can partially stall at any speed on any straight will give you a straight line advantage.

I mean at Monaco they 'only' go 178mph. If they can 185 by the speed trap, they are faster, advantage gained.

It's not rocket surgery.

[Gecko]

Dear SLC,

I find it a bit curious that you mention that the induced drag component is negligible for an F1 wing, yet then try and explain that the usual aerodynamic rules of thumb do not apply for an F1 wing because the rear wing is tilted at such an angle that stalling it will reduce both lift and drag.

I believe it is precisely the induced drag that is reduced by stalling the wing, and that it is the phenomenon of induced velocity that requires the geometric tilt of the rear wing needs to be so large in the first place. The reason that the rear wing is tilted at such a steep angle is that, by producing lift, it induces an upward velocity component onto itself, so the actual angle of attack of the wing in the airflow is smaller than the geometric one. Compared to a 2D (large span) situation, the induced velocity rotates the "lift" vector backwards. Therefore, when reducing "lift" (stalling) this causes a decrease in drag, just as your picture correctly shows. On a wing of a much larger span, the stalling of the rear wing components would however most likely not bring any drag benefits.

[Shaddock]

If McLaren remove the snorkel from the car for Monaco then its probably part of a switch. Unless of course they bring the mother of all snorkels, and use it as a constant stream of supplementary air to the rear wing.

Even at Monaco there are straits where a higher top speed would be useful.

Where?

[Giblet]

Really? You are joking yes?

Every single straight that you can go faster on, you can go faster on if the wing is less effective. Up the hill until bend?

Seriously... think about it.

[rifrafs2kees]

This whole knee controlled device is just ridiculous conjecture that's flooding this post. I am not an aerodynamist but until i see proof I won't believe that in the tight confines of an f1 car today, this "knee thing" is the best mclaren could come out with. It just doesn't make sense. Can't they calibrate and control the amount of air fed to the slot to create the necessary stall by varying the air inlet for the slot as we saw them do on one of jenson's practices? We don't know the purpose snorkel on the nose, we just don't know. Let's hold our peace until someone actually "knows" something we need to hear about.

[Shaddock]

Really? You are joking yes?

Every single straight that you can go faster on, you can go faster on if the wing is less effective. Up the hill until bend?

Seriously... think about it.

I have thought about it, you can only stall the wing at one set speed without driver inference. At Monaco the fastest part of the track in through the tunnel which is a right hander, then you are into the braking zone as you exit for the left-right chicane.

As a driver do you really want the wing stalling at the apex in the tunnel. If you tune it to stall earlier, ie the start finish straight then you will have to drive the tunnel section with a stalled wing.

[wrcsti]

This whole knee controlled device is just ridiculous conjecture that's flooding this post. I am not an aerodynamist but until i see proof I won't believe that in the tight confines of an f1 car today, this "knee thing" is the best mclaren could come out with. It just doesn't make sense. Can't they calibrate and control the amount of air fed to the slot to create the necessary stall by varying the air inlet for the slot as we saw them do on one of jenson's practices? We don't know the purpose snorkel on the nose, we just don't know. Let's hold our peace until someone actually "knows" something we need to hear about.

+1, I keep waiting for someone to say April Fools! But noone has so far. Hell even the snorkel doesnt make sense. WE KNOW THEY HAVE MULTIPLE AIR INLETS IN THE SCOOP! why cant this just be for driver comfort? Or about electronics? It all has to be with some new rule bending going on.