Reducing the drag of a two element wing through stall

[forty-two]

I suddenly thought of something.
Do you think Hamilton has got hollow knees?

Or perhaps Jenson has got hollow legs, which is more likely.

Well, maybe they should connect the hose to their brains... ha, ha.

So, is this in fact some sort of feed to allow for inflatable drivers? That would shave a few pounds off the car's weight I would have thought!

[Gecko]

And Gecko: I know your post was some time ago, but I'll reply here. You clearly have an understanding of what's going on, and I agree with what you say. After thinking about it, I don't mean to say that the induced drag component is negligible on the whole (when the wing is attached). However, I do think the most significant reduction in drag when the wing stalls is from the large reduction in pressure drag (due to the loading on the wing being massively decreased). Yes, the induced drag would also decrease due to this reduced loading (the decrease in loading will reduced the upwash which you get as a result of the trailing vortex system), but that component is still relatively small (I'd say 20-25% of the total drag delta). To be honest I've never had think about, let alone work out, the different components that make up the wing drag (hell, overall car Cd is all that really matters).

Dear SLC,

thanks for the reply!

I think we are mostly in agreement then. I will, however, maintain that the only reason that the pressure distribution on a loaded, mostly unstalled, wing does not press downward but rather somewhat in the direction of the flow is due to the induced upwash. Induced drag does manifest itself through the change in the wing pressure distribution, which is the phenomenon you are describing, and the drag due to this pressure distribution should directly correspond to the energy put into the wing upwash. As with many things in fluid dynamics, I believe we are simply describing the same effect from different, equivalent viewpoints.

I will take the debate one step further and state that stalling a part of the multi element wing would never give any reduction of drag in the case of a very wide wing (the 2D case). It is only because of the limited width and the corresponding upwash effects that one can exploit the phenomenon which you correctly described. Agreed?

[SLC]

And again, for those of you who think the McLaren slot is acting as a blown flap (and thus helping to prevent stall) are incorrect. This is what the Williams and Sauber wing are doing, and indeed what the McLaren 2009 wing did, but this has nothing whatsoever to do in terms of applied aerodynamics to the 2010 wing.

Hey SLC. Thanks for this interesting bit. Would you be able to share something more, or should we rely on the little riddle that you leave us with?

As far as the rest of the little rant goes, we are just normal people and some engineers trying to understand what's going on. I usually encourage people to talk and think about stuff that they do not know so that I can guide them, instead of just telling that they are wrong so why don't they just shut up and let the grown ups talk. If you are not satisfied with the discussion here, please keep it to yourself or attend a conference or two.

This is exactly the reason why my posts come off as rant-ish to you...: Little riddle? Have you not read *any* part of this thread? I've explained it as clear as I possibly can over the past 5 pages or so. The vector diagrams I linked to (ok ok fine, horrific MS Paints) show exactly how stalling the wing reduces the drag on the wing assembly. People just choose not to listen/believe me and go back to their own theory. I don't particularly care, but I know what McLaren are doing and anyone who doesn't think I am right is unfortunately wrong.

I will take your advice and keep information to myself. This will be my last post in this thread. For those of you who don't agree with what I've been saying, have fun arguing amongst yourselves.

I've already linked to this but Scarb's article on this explains the whole issue quite nicely: http://scarbsf1.wordpress.com/2010/03/0 ... -stalling/

Ignore the majority of the comments people have left, they are misguided. Just in case this wasn't clear by now: the slot in the flap element is there to facilitate the onset of stall on the wing which reduces the overall car drag.

[delacf]

The interesting thing, in my opinion, is how it works the air entering the airbox to produce the rear wing into losses. I do not believe in the theory of the knee-snorkel. The air entering the cockpit "loses all its speed". Not good for much. I dont think you can make any entry of air into the place that reaches the rear wing in good conditions.Greeting s

[autogyro]

The interesting thing, in my opinion, is how it works the air entering the airbox to produce the rear wing into losses. I do not believe in the theory of the knee-snorkel. The air entering the cockpit "loses all its speed". Not good for much. Greetings

The air flow from the shark fin intake to the slot can be fed through a restriction that is tuned to prevent effective blowing at a certain speed.
This would be a workable and intigral system needing no switching of the main flow.
The snorkel could be for something nothing at all to do with wing flow control.
Or it could be a variable and adjustable intake and it could be a 'knee' valve.
Any more for anymore?

[WhiteBlue]

I would laugh if it was just to cool some advanced CPU for monitoring the car. Remember they have to use the FIA ECU so might be restricted to much for testing / monitoring purposes on tests.

Did I dream it, or did I read some time ago that the "FIA ECU" was actually designed and manufactured by McLaren Technology?

If so, I doubt they'd have too much trouble running a "Custom" version if they needed some extra instrumentation for testing. I'm not sure if that would be legal or not, but providing they only use it during winter testing I imagine it'd be ok??

Yes, McLaren is the supplier. And also yes, they could be running something special at tests. There is no scrutineering at tests.

[Shaddock]

I would laugh if it was just to cool some advanced CPU for monitoring the car. Remember they have to use the FIA ECU so might be restricted to much for testing / monitoring purposes on tests.

Did I dream it, or did I read some time ago that the "FIA ECU" was actually designed and manufactured by McLaren Technology?

If so, I doubt they'd have too much trouble running a "Custom" version if they needed some extra instrumentation for testing. I'm not sure if that would be legal or not, but providing they only use it during winter testing I imagine it'd be ok??

The ECU is strapped up next to the engine, not up front in the nose. You data log on the car, not process, that's done in the pits.

[Pup]

SLC, thanks for your contributions - much appreciated.

[ringo]

I was expecting him to lose it one of these days He has been shouting from the roof tops for days.
He did a good job really. He stood to his conviction, he had diagrams, quotes from people in the know like Christian Horner and the offcicial F1 website technical drawings, so we can't blame the guy for getting impatient.

[Raptor22]

the guys an impatient arsehole who is yet to produce a proper CFD flow diagram to illustrate his point of view.
he claims to have the skill and means yet chooses not use those tools, instead poor MSpaint diagrams....something doesn't add up.

If his employer allows him time to post on internet forums then I'm sure they will let him use their Catia to generate the required flow diagrams to prove his point.

Instead all we have is constant hammering that he has explained it as simply as possible, yet even highly educated engineers don't understand the concept.
Something doesn't add up


Scarbs article has not been peer reviewed and no engineer from any other team has commented on the wing stall, ever. Sure Chritian Horner said wing stall has been used for years yet a few years back at a seminar at Pretoria University I asked Rory Byrne (yes THAT Rory Byrne) if there was any credibility behind upper element wing stall as had been reported in the F1 tabloids and his response was "don't believe everything you read about F1!"

It may well be that they are "Stalling" the upper element but I would appreciate being educated with numbers and proper illustrations and not by the ranting of someone insisting I must believe because he sad so.
The church minister hasn't got that right in over 30yrs, its unlikely some anonymous character on an internet forum will.

[Pup]

Whatever. I suspect this thread has run it's course. Motion to adjourn?

[SLC]

If his employer allows him time to post on internet forums then I'm sure they will let him use their Catia to generate the required flow diagrams to prove his point.

Right, so I wasn't gonna bite but I'm weak, and this *will* be my last post, but the above sentence alone tells me just how little you know about the aerodynamic process within modern F1.

Good day.

[forty-two]

SLC, thanks for your contributions - much appreciated.

+1
All posts have made interesting reading

[Scania]

could someone explaine what the fuction it is & how it work plz?

[ringo]

the guys an impatient arsehole who is yet to produce a proper CFD flow diagram to illustrate his point of view.
he claims to have the skill and means yet chooses not use those tools, instead poor MSpaint diagrams....something doesn't add up.

If his employer allows him time to post on internet forums then I'm sure they will let him use their Catia to generate the required flow diagrams to prove his point.

Instead all we have is constant hammering that he has explained it as simply as possible, yet even highly educated engineers don't understand the concept.
Something doesn't add up


Scarbs article has not been peer reviewed and no engineer from any other team has commented on the wing stall, ever. Sure Chritian Horner said wing stall has been used for years yet a few years back at a seminar at Pretoria University I asked Rory Byrne (yes THAT Rory Byrne) if there was any credibility behind upper element wing stall as had been reported in the F1 tabloids and his response was "don't believe everything you read about F1!"

It may well be that they are "Stalling" the upper element but I would appreciate being educated with numbers and proper illustrations and not by the ranting of someone insisting I must believe because he sad so.
The church minister hasn't got that right in over 30yrs, its unlikely some anonymous character on an internet forum will.

I hear you man, I get what you are saying, we need concrete proof.
might have to wait till the year is through and we get a season review.