Blowing the Wing - what is it?

[gato azul]

While I like the animation, and the work the guy has put into it, I do not think, that this single airfoil at low AoA is a good representation of what is happening on an F1 rear wing.
But is o.k. , no need to get our trousers in a twist about it - everyone can make up their own mind about it.

As for the "dead zone" thing, I thought there was a guy on here once, who talked about the "dead zone" wing of McLaren, something which later was called the F-duct.
My question is, did they call it that just for "show" or has it some reference to the term "dead zone" (a.k.a. "dead water zone")
which is commonly used in fluid dynamics?

[superdread]

While I like the animation, and the work the guy has put into it, I do not think, that this single airfoil at low AoA is a good representation of what is happening on an F1 rear wing.
But is o.k. , no need to get our trousers in a twist about it - everyone can make up their own mind about it.

Agreed, the choice of camber (and AoA) is way off, and a second element would be nice.

As for the "dead zone" thing, I thought there was a guy on here once, who talked about the "dead zone" wing of McLaren, something which later was called the F-duct.
My question is, did they call it that just for "show" or has it some reference to the term "dead zone" (a.k.a. "dead water zone")
which is commonly used in fluid dynamics?

Maybe they call the area between the separated flow and the wing surface "dead", velocity-wise there is nothing going on there (in comparison the the normal flow over the wing).

[Cam]

I haven't seen any proven details on how a passive switch could actually work. There is that Ferrari front wing video and the Mercedes front wing where-by it seems they simply limit the amount of air through the size of the tubes to control the device.

Is it possible to use g-force to control a switch to turn a passive device on/off or limit the flow?

[raymondu999]

This idea was proposed a while back, but I'm not sure if it would be legal under the scope of the current regulations.
[youtube]http://www.youtube.com/watch?v=r2WnLNbkpOw[/youtube]

I wonder if what Lotus is really doing with the twin-eared air box design is to detect flow differences between the two ears. Would such a switch be possible? Ie if the two sides are getting equal amounts of flow, the car deduces that the car's trajectory is straight, or at least straight enough, to stall the drag. When it detects less air on one side, it deduces that it doesn't have a straight trajectory and so goes back into high downforce position.

[Cam]

Cheers Ray. +1. That's a really clever device.

[hollus]

To the video above, any device that uses any physical moving parts to open or close ducts is forbidden, even if they move passively themselves.

I posted something similar to this in the Lotus page, it looks relevant here:



In these pictures it almost looks like those ears are not covering future channels, but already building very thin channels themselves. We also know that the ears, though blanked in Jerez, are channels themselves. So I am playing with the idea of the Lotus having a total of 5 channels around the air box. The big ears would be for cooling, hence blanked in Jerez, and the narrow slits in between for feeling the attitude and state of the car
In either case, they are significantly behind the main intake, and I can only think of a good reason for that: to be shadowed by the engine's main intake. It is plausible that they might act as a directional control for the passive DRD:
a) If the car is turning with significant yaw, one of them will get shadowed and ingest significantly less air. I assume that they merge further down and in that case the additive flow is less than without yaw. This would reduce the tendency of the system to activate while cornering.
b) If the throttle if off, as Zonk suggests, the main air intake will suffer spillage, ruining the flow into these middle channels. This would also reduce the tendency of the system to activate while cornering (if you corner at full throttle, then you don't care too much if it activates), and it would also disable the system while braking (but for the cold blowing, but still to a point).
Both effects would favor adjusting the system with a lower activation speed, which would ideally only apply when accelerating in a straight line.

This is what I mean: Blue is flow for the engine, red for the DRD. The channels depicted would be the narrow slits, not the large ears.



If there are indeed 5 channels, the slits look to small to carry the main flow to the DRD outlet, but maybe they can carry enough to act as the trigger signal?
Just a theory.

[Cam]

To the video above, any device that uses any physical moving parts to open or close ducts is forbidden, even if they move passively themselves .

Would an amount of fluid fall into that category if moving parts?

[hollus]

Not gases, certainly, mostly by convention, convenience and precedent. Liquids are interesting, are they even "parts"? How would they be treated in scruteneering?
Afaik, this is a blank in the rule book, but could be made to fail under movable ballast?
Anyways, do you have a very interesting idea you would like to share?

[Just_a_fan]

If the "ear" air intakes do feed a wing blowing / DRS system then I think that the reason they are separated from main intake is to stop the spill from the main intake from affecting the DRS inlets.

If the DRS works by being switched by the flow rate in to the ear inlets, then spill from the main intake, such as when coming off throttle, could cause the DRS to activate just at the time when you don't want it to activate.