Reducing the drag of a two element wing through stall

[Holm86]

has that front snorkel changed again

That's what I said but was rebuffed by someone saying that it was like that in Jerez.

you said that yesterday right??? but the snorkel didnt look like that yesterday .....
that snorkel is new for today ....

[Just_a_fan]

Looks like it did. I'm really curious what are they up to? I don't believe in all that 'active knee steering theory', but still why are they paying so much attention to that vent?

I've been wondering about this vent too. Looking at:



we can see that it is located over the bell crank rocker for the front left suspension. This makes me wonder if they are cooling something suspension related. Why do that? Because the suspension is working harder when the car is fully fuelled. Perhaps they have a remote reservoir there for the third spring (or something).

Alternatively, that side is the brake pedal side so I did wonder if it might be cooling the brake reservoir - again because the fully fuelled cars work the brakes harder.

On that picture you can also see, either side of the 'e' of Vodafone on the nose, that there are 2 holes. I wonder if they are to allow adjustment of the end of the torsion bars (which is normally accessed from the end of the tub when the nose is removed). I think this will allow a quick ride height adjustment during the pitstop to allow for a lighter car. I don't think these are the fixings for the nose as these are usually side mounted.

What do people think of these ideas?

[Shaddock]

Looks like it did. I'm really curious what are they up to? I don't believe in all that 'active knee steering theory', but still why are they paying so much attention to that vent?

I've been wondering about this vent too. Looking at:



we can see that it is located over the bell crank rocker for the front left suspension. This makes me wonder if they are cooling something suspension related. Why do that? Because the suspension is working harder when the car is fully fuelled. Perhaps they have a remote reservoir there for the third spring (or something).

Alternatively, that side is the brake pedal side so I did wonder if it might be cooling the brake reservoir - again because the fully fuelled cars work the brakes harder.

On that picture you can also see, either side of the 'e' of Vodafone on the nose, that there are 2 holes. I wonder if they are to allow adjustment of the end of the torsion bars (which is normally accessed from the end of the tub when the nose is removed). I think this will allow a quick ride height adjustment during the pitstop to allow for a lighter car. I don't think these are the fixings for the nose as these are usually side mounted.

What do people think of these ideas?

I doubt very much if its suspension related, there is nothing there to cool or needs cooling. However, if the pipe from the snorkel passed along the floor of the cockpit and then up into a ‘chamber’ or junction in the air box then things could get quite interesting.

My theory:-

Air going into the junction that ‘possibly’ travels in the fin to the blown rear wing could be partially/diverted into the intake for the engine or oil cooler instead by changes in pressure from the air coming in via the snorkel in a passive way, no moving valves or switches. The driver can control the pressure from the snorkel simply by putting his foot on the squeezable tubing on the floor (e.g. long straight – stalls rear wing – less drag).

[Pup]

Raptor, the question of this thread is "if the wing is stalling, then why?" If that isn't a discussion you're interested in having, that's cool, but just saying that the wing doesn't stall again and again is a bit pointless - we got it. Also, this thread was created to discuss the concept in general, and isn't meant to be an extension of what specifically the McLaren wing does - though obviously that it our primary reference at the moment. But we're also interested in the Ferrari wing of a few years back, which neither sucked nor blowed, in any sense of the terms.

OK, so we are all aware of the basic acceptance that stalling is bad. But some of us are trying to approach this with an open mind - even if in the end, the theory is debunked. Like I say, if you want to join that discussion, please do.

We have a working hypothesis as to why stalling an F1 wing might be beneficial, and we have some evidence already that stalling and F1-like wing does not produce the expected levels of additional drag. With that in mind, I don't think your derision is called for.

Again, I think you've got valuable input to make here; but I see this slipping into an argument, and I know we'd all rather avoid that.

[hollus]

I hate to fuel the conspiracy theories and I would rather think that the misterious airflow is influenced by the helmet, actively or passively; but those snorkels keep changing in shape and still are always right above the left knee, left being the braking leg. This also would fit with reducing drag (at the cost of downforce) in the straights while recovering for braking.
But that would be so ilegal!
Or maybe it wouldn't, if I am happy using the helmet to control flow, why not the knee! One can always claim that the tube is for cooling the rear side of the rear wing anyways...

[conni]

I hate to fuel the conspiracy theories and I would rather think that the misterious airflow is influenced by the helmet, actively or passively; but those snorkels keep changing in shape and still are always right above the left knee, left being the braking leg. This also would fit with reducing drag (at the cost of downforce) in the straights while recovering for braking.
But that would be so ilegal!
Or maybe it wouldn't, if I am happy using the helmet to control flow, why not the knee! One can always claim that the tube is for cooling the rear side of the rear wing anyways...

WHY would it be illegal?? the rules state that the driver cant adjust the rear wing
and he wont be will he!! he will be adjusting the airflow that goes over the rear wing

conni

[Pup]

From a very philisophical and not so mathematical point of view, I'll consider a rear wing a single element flat panel at an angle of 45 degrees to the floor. By its mere being in the flow, high pressure will accumulate in front of it and low pressure behind. This pushes perpendicularly to the wing, thus the car is pushed partially downwards and partially backwards. I'll call these pressure forces. Now, the wing, if the airflow is attached, will receive air flowing horizontally at 250Km/h and produce air flowing at 45 degrees to the floor, presumably at close to 250Kmh along the wing plane. This air has thus now moving forwards at the square root of 2 less than the initial horizontal speed, or about 175Km/h. It has lost 75Km/h of horizontal speed (relative to the car, relative to the ground it has gone from stationary to 75Km/h moving forwards) and must thus be pushing the car backwards. This air is also now moving at 175Km/h vertically and thus it must push the car downwards. I'll call these flow forces. Do not dismiss flow forces, a F1 car travelling at 300Km finds in the order of 100Kg of air in its way every second, and we all know that it mostly pushes it all upwards.
Thus, looking at pressure forces, if you get more downforce on the car, you have to pay as more drag on the car. Looking at flow forces, if you get more downforce in the car you also must pay as more drag in the car. The relative magnitudes can vary of course and my very crude plank wing does not even try to capture it.
As I see it, if the wing would go from nice attached flow to a stall, be this total or partial, the pressure forces would likely increase (more downforce and drag on the car), while the flow forces would for the most part, dissapear, (less downforce and less drag on the car). Flow forces probably have a better downforce to drag ratio than pressure forces, but in the straight they are not so needed. The car would not lose all downforce, as it would not lose all drag. In stall, it gains more of both, downforce and drag from prossure forces, and loses both downforce and drag from flow forces. It is all a quastion of the relative magnitudes.

I think what you're getting at is the relationship between induced and form drag. This seems to be the general consensus as to where an answer to the conundrum might lie.

In the diagram from that page, you can see how the two interact with an airplane wing...



In this example, the induced drag falls as the wing is leveled off with speed. Of course, in F1, the wing is fixed, so induced drag not only begins at a much higher level (due to the higher angle of attack), but also rises instead of falls with speed. So it's easy to contemplate that in a stall, the loss in induced drag might well more than make up for the additional form drag that might be incurred. Add that to the idea that an F1 wing is far more draggy than an airplane wing, even in an unstalled state, and it becomes even more intriguing since the difference in drag between a stalled and unstalled state will be less than in aviation.

Like you say, we just need the flow diagrams to prove it.

[Just_a_fan]

I doubt very much if its suspension related, there is nothing there to cool or needs cooling. However, if the pipe from the snorkel passed along the floor of the cockpit and then up into a ‘chamber’ or junction in the air box then things could get quite interesting.

My theory:-

Air going into the junction that ‘possibly’ travels in the fin to the blown rear wing could be partially/diverted into the intake for the engine or oil cooler instead by changes in pressure from the air coming in via the snorkel in a passive way, no moving valves or switches. The driver can control the pressure from the snorkel simply by putting his foot on the squeezable tubing on the floor (e.g. long straight – stalls rear wing – less drag).

I would have thought that if they just wanted air to control the rear wing thingy then they could just have used the nose cone vent and no one would have thought too much about it.

Of course, the top vent could just be cooling the ECU which they might have moved to make room for the clever rear wing stuff under the engine cover...

[tok-tokkie]

Looks like it did. I'm really curious what are they up to? I don't believe in all that 'active knee steering theory', but still why are they paying so much attention to that vent?

Several posters have referred to that as a vent. That is an air inlet; snorkel it was called in the previous post. A vent is at the other end of a duct (can be an anus too).

Main Entry: 2vent
Function: noun
Etymology: Middle English, anus, outlet, probably from Anglo-French, wind, draft, outlet
Date: 15th century

1 : an opening for the escape of a gas or liquid or for the relief of pressure: as a : the external opening of the rectum or cloaca : anus b (1) : pipe 3c, fumarole (2) : hydrothermal vent c : an opening at the breech of a muzzle-loading gun through which fire is touched to the powder d chiefly Scottish : chimney, flue
2 : an opportunity or means of escape, passage, or release : outlet <finally gave vent to his pent-up hostility

Source Websters

[Shaddock]

I doubt very much if its suspension related, there is nothing there to cool or needs cooling. However, if the pipe from the snorkel passed along the floor of the cockpit and then up into a ‘chamber’ or junction in the air box then things could get quite interesting.

My theory:-

Air going into the junction that ‘possibly’ travels in the fin to the blown rear wing could be partially/diverted into the intake for the engine or oil cooler instead by changes in pressure from the air coming in via the snorkel in a passive way, no moving valves or switches. The driver can control the pressure from the snorkel simply by putting his foot on the squeezable tubing on the floor (e.g. long straight – stalls rear wing – less drag).

I would have thought that if they just wanted air to control the rear wing thingy then they could just have used the nose cone vent and no one would have thought too much about it.

Of course, the top vent could just be cooling the ECU which they might have moved to make room for the clever rear wing stuff under the engine cover...

Possibly, but can the snorkel provide enough air to rear wing to make a difference when it's switch on/off, or would you use it as a relay controlling the air direction from the the flow from the air box.

[Pup]

WHY would it be illegal?? the rules state that the driver cant adjust the rear wing
and he wont be will he!! he will be adjusting the airflow that goes over the rear wing

conni

I guess if the airflow is controlling some sort of valve or flap, then the FIA could consider it a moveable aerodynamic device - and probably rightly so I'd have to think. But if somehow this was all accomplished pneumatically, with no moving parts, then I could see your point.

But wow, what a convoluted system that would be.

Hey, I'm open to anything, but count me as more than a bit dubious at this point.

[Pup]

I would have thought that if they just wanted air to control the rear wing thingy then they could just have used the nose cone vent and no one would have thought too much about it.

Playing devil's advocate, it might be impossible to get such a duct around all the suspension and steering bits that are packed in between the nose and the river.

Of course, the top vent could just be cooling the ECU which they might have moved to make room for the clever rear wing stuff under the engine cover...

It could easily just be for cooling, though I doubt any electrical equipment would have been placed inside the hot engine bay to begin with. I think all that stuff usually goes on the floor around the driver.

[Mysticf1]

looking at the above shot, it seems the duct isnt being used to the rear wing, the bodywork / fin attached to the rear wing is much narrower and does not flare out as it attaches to the wing...

[Shaddock]

I have just knocked this up in Powerpoint



I think it may be a little more complicated than this, but the basic principle might work.

[mith]

Several posters have referred to that as a vent. That is an air inlet; snorkel it was called in the previous post. A vent is at the other end of a duct (can be an anus too).

Good to know. I'm still polishing my English.