Reducing the drag of a two element wing through stall

[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...

[djos]

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

[ArchAngel]

...I guess my gut feeling is that there isn't a whole lot of room for left/right swinging of a knee to alter the airflow through that inlet, but I have no proof. I like ringo's drawings and idea, but I'm not sure if they'd work in the confines of the actual car.

+1

With hardly enough room for lateral leg movement, the legs/knees would likely be leaning hard in the opposite direction of most turns/corners. The proposed leg/knee "switch" would then be very vulnerable to inadvertent "activation" at the most inopportune moments on track.

Interesting specualtions & discussions from everyone, though. Keep up the good work!

[FuzzyDice]

this is very interesting topic so if i understand it right we have straight line, high speed, low downforce, low drag

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?

[nacho]

Why use a knee if you could use the left hand? That stalling device would be used well after they exit the corner where they anyways might be adjusting diffs etc.

[fausto cedros]

Hi, this is my first post, so first of all let me thank you for all the gasoline you give to my brain to keep it running.
I am an aerodynamicist, and I've worked in the past as race engineer and project engineer in an aircraft building company.
I've read all the discussions, but "stall" does not sound like the right word to me. I mean, i am looking forward to the low downforce circuits to have some more hints, but i guess the slot is simply a way to have a boundary layer interaction and maybe keep the flow attached at a steep AOA. Maybe the wing would be otherwise stalled that steep without the blown slot?I guess it's not reducing the drag by stalling the wing, but it's obtaining the same downforce at a lower AOA, since the higher straight speed. But, as long as we don't have any test evidences (numerical, thanks Ringo, or otherwise) it's really hard to tell.
Thank you everybody again, keep it running flat out.

[di44ety]

I don't believe the snorkel theory but if it's real it's probably something like this:

All rigid parts , no degree of freedom. Only moving part is the knee, which is not bodywork construction. In this case the knee has to be the main switch. Nonetheless this is just part of the solution, i don't know what's going on behind the from this pipe to the fin; ie if it's real.

With knee movement is impossible. Knees are stationary for greater safety.

[marcush.]

So ...
if the front flap are allowed to move as movable aero device...why not open with the flap a duct providing that movement instead of moving knees???

the flap has an appendage or is formed to close a duct in the fully down position and opens the duct when opened up.Voila ,two modes available for an additional duct ,
could lead throu mainflap and wingstays through the whole car.
Opening at the leading edge of the front wing ,full ground speed available.
Fully legal.

you could maintain even the flap without any ducting added will have an effect further back in the car so the duct is nothing more than a clever routed elaborate turning vane within the legal dimensional constraints of the set of rules....


wish I had that idea a few days ago...

[autogyro]

I don't believe the snorkel theory but if it's real it's probably something like this:

All rigid parts , no degree of freedom. Only moving part is the knee, which is not bodywork construction. In this case the knee has to be the main switch. Nonetheless this is just part of the solution, i don't know what's going on behind the from this pipe to the fin; ie if it's real.

With knee movement is impossible. Knees are stationary for greater safety.

Yep.
Has to be a direct connection to the fin to introduce a side flow to move the fin flow away from the slot. The pit crew will probably fine tune the adjustment in stops like they do with wing angles.
the size of the snorkel intake is adjustable to vary the speed at which this happens.

[nacho]

Are there any valve experts here? I can imagine a kind of a hinge valve with a spring could be easily designed to pop completely open at certain speed (air pressure) and close completely down when the pressure drops (speed is lower). I don't think that could be called as an active device? If so then using the extra airbox vents would make more sense and be a lot more powerful than the snorkel.

[marcush.]

Are there any valve experts here? I can imagine a kind of a hinge valve with a spring could be easily designed to pop completely open at certain speed (air pressure) and close completely down when the pressure drops (speed is lower). I don't think that could be called as an active device? If so then using the extra airbox vents would make more sense and be a lot more powerful than the snorkel.

As the front flap is officially allowed to be a movable aero device ,why not use it exactly for this activation?

[feynman]

That is a photo of a Ferrari (the red gives it away, not much gets past me y'know).

The silver car is usually configured differently, that is why the McLaren drivers emerge from the cockpit wearing one or two kneepads. They had enough room and movement in there for a second brake pedal, I am sure they could find room for either a knee-sized socket, or a similar wind-instrument layout on the floor, the holes to be stood on with a racing boot.


The chap concerned that the snorkel airflow is too limited, should probably take a few minutes to read the previous half-dozen pages, where it is explained how a small pneumatic signal can be used to switch a much larger airflow.

And cooling? What has moved into the cockpit that suddenly needs that sort of aggressive cooling. In four test sessions, we have seen at least 5 different and distinct design of snorkel inlet on the car, including possibly one with a pitot tube inside. I remind you that in the same time-period, we saw only seen two designs of front-wing endplate.
Seems a lot of valuable engineering resource and scarce test-session time to be playing about with just a plain-vanilla cooling inlet to keep the radio cool, dontcha think?

[nacho]

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?

[jason.parker.86]

I am no "valve" expert, nor am I any type of expert, but it is possible to get vales that open under pressure. Take a standard swing / check valve that you use on your toilet system. After a certain amount of pressure, it will open. The idea is that it stops backflow, thus creating a one way street, stopping any water coming the other way.

So is it not within the rules to have a valve that opens up under x PSI / BAR? I do not know if this would be against the rules, but I cant see why this would be any different from Ferrari's flexible wing, which I believe was banned?

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?

[hollus]

I am no "valve" expert, nor am I any type of expert, but it is possible to get vales that open under pressure. Take a standard swing / check valve that you use on your toilet system. After a certain amount of pressure, it will open. The idea is that it stops backflow, thus creating a one way street, stopping any water coming the other way.

So is it not within the rules to have a valve that opens up under x PSI / BAR? I do not know if this would be against the rules, but I cant see why this would be any different from Ferrari's flexible wing, which I believe was banned?

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?

Moving parts affecting the aero are banned. A valve with physical moving parts would be clearly illegal whether actively or passively controlled, the same way the flexi-wings were. On the other side, a valve with no moving parts, like those fluidic valves would be legal (really people, go back to read past posts, in this case in page 113). One could also consider legal (maybe) things where the moving parts are not considered part of the aero, only that pretty much leaves one with the driver as the only possible moving part.

Just to remind everybody of the problem with a fully passive system (which would still be a nifty engineering concept): if you stall the wing (totally or partially) above a certain speed, you also lose your downforce at the beginning of the breaking area, and then when the downforce comes back it would be difficult to not lock the wheels.
Of course, as always that is a case of balance. Probably some straights are long enough that the greater straight speed wuold compensate for the longer braking area.
Another take on this would be if the system is really such a compromise that you don't win any extra lap time, only straight line speed at the cost of braking capacity. Such a car would still be a strategic asset, if you can slipstream but the other cars effectively can't slipstream you, as you have lower drag anyways. Overtaking/defending from such a car would be a total nightmare.