Reducing the drag of a two element wing through stall

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timbo
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Re: Vodafone Mclaren Mercedes MP4/25

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Will it work with pressures close to atmospheric?

Also, as I said before it should be very reliable, and not affected much by, say, yaw conditions, car ahead etc. You don't want "stall system" to engage when you're in the corner.

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forty-two
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Re: Reducing the drag of a two element wing through stall

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Please forgive me if this post is a little off-topic or clearly ill-informed but...

Does anyone think that there's even the most remote chance that what we are looking at here is actually there as an air brake?

A lot of the discussion on here talks of stalling causing an increase in drag rather than a reduction, and it occurs to me that given the higher fuel loads this year it might be advantageous to have an additional bit of oomph when it comes to slowing a vehicle down at the end of a fast straight. (Just like the Veyron does when in "high speed" mode but the brake is applied, but they have the luxury of being able to change their wing's AoA).

An additional bonus to this would presumably be significantly reduced wear on the tyres when braking, a reduction in wear and excessive heat on the brakes themselves (anyone remember Webber's brakes giving up toward the end of a race last year... Singapore I think?).

While I don't at this moment buy the idea of the "driver's knee covering hole" concept, I just think that the idea of a driver at full tilt having to locate a hole in a tube in the cockpit... with his knee is a little too much to buy. BUT if for example, the inlet from that snorkel 'just happened' to be run 'past' the brake pedal lever, and the driver exerting pressure on the brake pedal caused a pipe to be squashed, triggering the blown flap stall to be initiated.....

While I imagine that any such effect will be relatively short lived as the car decelerates, it might be enough to keep the brakes below some critical temperature threshold where they start to degrade, whilst also giving the car a moment to slow down before the tyres really start working to slow the car.

Whatever they're up to, I love this kind of innovative (or indeed diversionary) ideas.

I am happy to defer to the obvious wealth of knowledge in this area held by so many members here (oo-errr sounds a bit rude!) but I thought I'd chuck the idea in to see what everyone thinks!
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myurr
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Re: Vodafone Mclaren Mercedes MP4/25

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timbo wrote:Will it work with pressures close to atmospheric?

Also, as I said before it should be very reliable, and not affected much by, say, yaw conditions, car ahead etc. You don't want "stall system" to engage when you're in the corner.
Would also be interesting to know how such a system would be affected by turbulence - both in general and when following another car.

Just_a_fan
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Re: Vodafone Mclaren Mercedes MP4/25

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myurr wrote:
timbo wrote:Will it work with pressures close to atmospheric?

Also, as I said before it should be very reliable, and not affected much by, say, yaw conditions, car ahead etc. You don't want "stall system" to engage when you're in the corner.
Would also be interesting to know how such a system would be affected by turbulence - both in general and when following another car.
And how it might deal with potentially large wind speed variations. If there's a 20mph breeze blowing across the track you're potentially asking this thing to do its thing at two different points on the track with 40mph difference in wind speed.

Perhaps air speed doesn't affect it but then how does it 'know' when to operate without external (and therefore illegal?) interaction?
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horse
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Re: Reducing the drag of a two element wing through stall

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Pup wrote:You guys let me know when you're ready to approach this issue with any sense of order.

OK, I'll just come back when the unicorns are gone. :roll:
All right, calm down now, Pup. I agree that a number of good qualitative arguments have been given and some further quantitative arguments would be required to differentiate between them. Unfortunately, because we don't know the configuration of the wing or the blowing system, any results from CFD are still just conjecture. I'm also sure we don't have the time to validate our models properly, so I don't think we can reach the true answer here, especially for the MP25 wing. Still, an attempt at simulating the wing in (partial) stall to see if drag could be reduced would be widely appreciated I'm sure.

I just wonder if the argument could be brought forward by considering the complication of implementation. It seems like the direction of injection must be fixed and the flow controlled in an on/off method, perhaps, by the driver. Nevertheless, the amount of flow going through the jet is still likely to change dependant on the speed on the car, unless there is something more clever in the flap/fin. Somehow I can't see them putting too complicated equipment up there on weight considerations, so I suspect it's relatively simple. So the issue is, can these systems work over a range of speeds - are they durable? Indeed, could the nose port provide the same tuning that the restriction they were using in the early tests achieved?
forty-two wrote:Does anyone think that there's even the most remote chance that what we are looking at here is actually there as an air brake?
forty-two, it's a difficult one to answer, this, because a number of arguments are pushing for a stall which will reduce the drag of the wing. I don't know if, by the same method, you could increase the severity of that stall to act as an air brake.

At the same time, I don't see why you couldn't be completely right. I'm sure an air brake would offer some advantages with the heavier cars this year. Again, because we can't quantify the relative performance of any of these theories it's hard to say whether improved braking would be of more benefit than improved top speed. If you could do both, of course....

Pedal controlled rather than knee controlled also sounds interesting. Especially for an air brake, where full-on braking is most likely to be where you need the extra braking performance.
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Giblet
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Re: Vodafone Mclaren Mercedes MP4/25

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Martin Whitmarsh is a smart man. I am sure after the DDD fiasco of last year, lawyers have been consulted, and a human being, being a valve, is not covered under the rules as far as I know.

The driver is a separate entity form the car, so it does not land under the rules of sprung parts.
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horse
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Re: Vodafone Mclaren Mercedes MP4/25

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tok-tokkie wrote:Wiki on fluidics http://en.wikipedia.org/wiki/Fluidics

It includes this diagram of a fluidic amplifier but I would call it a flip-flop valve.
Image

A pulse to the side port C1 causes the flow to flip across to outlet O2 etc...
How does the pulse get supplied with the knee business? If it's an on/off type system, then there will be a continuous flow (to C1) or not, right? Or is there a different setup?

Where will the alternative output go? Into the airbox?
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Shaddock
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Re: Vodafone Mclaren Mercedes MP4/25

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horse wrote:
tok-tokkie wrote:Wiki on fluidics http://en.wikipedia.org/wiki/Fluidics

It includes this diagram of a fluidic amplifier but I would call it a flip-flop valve.
Image

A pulse to the side port C1 causes the flow to flip across to outlet O2 etc...
How does the pulse get supplied with the knee business? If it's an on/off type system, then there will be a continuous flow (to C1) or not, right? Or is there a different setup?

Where will the alternative output go? Into the airbox?
The alternate air could go to the oil cooler and exit the fin to the rear. If there were a pipe in the cockpit with a hole or flap cut out of it so snorkel air could escape, force from a knee seals this pipe and air pressure enters a version of this chamber at C.

pipex
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Re: Vodafone Mclaren Mercedes MP4/25

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Confirmation of the stalling wing theory?

http://www.telegraph.co.uk/sport/motors ... um=twitter
"We will have to wait and see".

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Shrieker
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Re: Vodafone Mclaren Mercedes MP4/25

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tok-tokkie wrote:Wiki on fluidics http://en.wikipedia.org/wiki/Fluidics

It includes this diagram of a fluidic amplifier but I would call it a flip-flop valve.
Image

A pulse to the side port C1 causes the flow to flip across to outlet O2 etc...
Yes !!!

This IS how I imagined it would work right after reading SLC's first post about an operated system !

Great Stuff !!! + Props =D>

The stream entering the control ports may be much weaker than the stream being deflected

:lol: :mrgreen:
pipex wrote:Confirmation of the stalling wing theory?

http://www.telegraph.co.uk/sport/motors ... um=twitter
Awww the 'toys' are gonna come out. I think it won't be declared illegal, though.
Last edited by Shrieker on 04 Mar 2010, 00:41, edited 3 times in total.
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newbie
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Re: Reducing the drag of a two element wing through stall

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Christian Horner:

“Basically, if you stall the wing you take all the drag off it and pick up straight-line speed,” Horner explained. “It’s something that’s been done quite a lot over the years but with the wing separators you’re not supposed to do that.”

Raptor22
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Re: Vodafone Mclaren Mercedes MP4/25

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very interesting concept

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horse
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Re: Vodafone Mclaren Mercedes MP4/25

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Shaddock wrote:If there were a pipe in the cockpit with a hole or flap cut out of it so snorkel air could escape, force from a knee seals this pipe and air pressure enters a version of this chamber at C.
But that gives a continuous flow to C, whereas the switch works with a pulse, right, not a continuous flow.
"Words are for meaning: when you've got the meaning, you can forget the words." - Chuang Tzu

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Shaddock
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Re: Vodafone Mclaren Mercedes MP4/25

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Shrieker wrote:
tok-tokkie wrote:Wiki on fluidics http://en.wikipedia.org/wiki/Fluidics

It includes this diagram of a fluidic amplifier but I would call it a flip-flop valve.
Image

A pulse to the side port C1 causes the flow to flip across to outlet O2 etc...
This IS how I imagined it would work right after reading SLC's first post about an operated system !

Great Stuff !!! + Props =D>

The stream entering the control ports may be much weaker than the stream being deflected

:lol: :mrgreen:
No reason you couldn't use a multi chambered/staged device to overcome that problem. If you shape the chamber so the rear is the default exit, then the snorkel air pressure will just move the airlflow across to the oil cooler when needed.
Last edited by Shaddock on 04 Mar 2010, 00:49, edited 1 time in total.

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Shrieker
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Re: Vodafone Mclaren Mercedes MP4/25

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Well...Umm... Actually i didn't state that as a problem. That's how it's supposed to work, i reckon. The answer to the question " how can such a small amount of air through a tiny scoop can have an impact on the rear wing air flow".
Last edited by Shrieker on 04 Mar 2010, 00:49, edited 2 times in total.
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