Ground Effect - Bring It Back

[bhall II]

It seems you are assuming your opinion is reality. It is not, it's just an opinion like everyone else's, including mine.

Trust me; I'm keenly of aware of how it looks. But, it doesn't change the fact that it's all here for everyone to see.

For a sport that prides itself on science-based technological innovation, it has a bizarre tendency to rely on anecdotal evidence when it comes to initiating change. For example, the most dramatic aerodynamic upheaval in the sport's history created a situation in which this...



...became this...



...because everyone thought it would improve overtaking, and here's what happened as a result:



Nothing. The change was statistically insignificant (even though instances of overtaking were actually reduced).

I'm beginning to think the most difficult task in the world is to prove that correlation doesn't equal causation. There are people who can look at this...

...and still somehow believe that refueling is bad for overtaking, despite the clear lack of any real evidence to support it. Downward trends in overtaking are far and away most pronounced for periods in which refueling is banned.

I don't think anyone denies that "dirty air" makes overtaking more difficult. Ultimately, however, it is not the reason why overtaking tends to become scarce over time. You have to look elsewhere for that answer.

[void]

Don't forget about the boring circuits that looks like a slot car tracks.

[rjsa]

I like charts and trends too. Check this out:

[bhall II]

That makes as much sense as a football bat. Then again, so do calls to move from one ground effect solution to another ground effect solution in order to affect something aerodynamically that cannot be affected aerodynamically.

If we're going to wish upon a star, can we at least aim for something a bit more substantial than increased overtaking? Think of the children!

Actual screens from Williams' design office

That's a real F1 car, and every blue area you see represents a negative pressure coefficient caused by the Venturi effect.

[Andres125sx]

Now, if you want a series in which "dirty air" is totally irrelevant, solving the problem is generally quite simple, and you even get to make a few choices: you can either open up the rules such that genuine aerodynamic performance differentiation is possible or you can standardize virtually everything such that it allows the sport to implement very basic aerodynamic devices that aren't especially sensitive to "dirty air," devices that would otherwise lead to ENORMOUS amounts of downforce (and "filthy air") if given enough room to develop them.

So there are devices wich aren´t specially sensitive to "dirty air". That´s definitely a step forward, you accepted this after 9 pages saying dirty air problem is next to imposible to reduce. Finally!

And yes, as you said those devices would lead to enormoous amounts of downforce... if given enough room to develop them. Same as wings, what´s the difference?

That´s the reason this is F1, not CanAm. There are rules to limit development and total downforce. Those rules wich today limit wing size, placement, rigidity, etc. would also limit downforce of those devices, but they would trade downforce from wings, with downforce from floor/GE, wich will result in cars with same downforce as today (or more, or less, what you prefer, that´s dictated by the rules) but less problems with dirty air.

[Andres125sx]

eg about 40000 Cessna 150/152/172 etc planes had full flap set to 40 deg
the drag typically prevented any climb (ie when abandoning an approach), the pilot having to make an immediate flap reduction (then around 1982 Cessna cut the full flap setting to 30 deg, and most light planes have this simpler arrangement)

in airliners the LE flap is always deployed with TE flap deployment - these at relatively low speeds
but the LE is also deployed without any (or any significant) TE flap deployment - this at higher speeds eg 200 kt


so I think that WT (tip vortices) of our car depends on the DF more than the drag the 'extra' drag goes more towards giving the wake a forward velocity ? - this is also a disadvantage (as hollus posted)

I think we´re saying more or less the same, but different ways. The only thing I´m not sure if agree if about if WT depend more on the DF than drag...

It´d be great to compare the WT of a plane in approach config (with full flap depolyment, LE, airbrakes, etc.) with the same cruising. Both scenarios create same lift, but different ways, one with a cambered wing at low speeds with lots of drag, and the other with a flatter wing at higher speeds with much reduced drag.

I´d incline to say WT will be higher on approach config, I´m not saying lift/downforce does not affect WT, but I´d say drag also affect on a huge proportion.

full flap setting is designed to give essentially more drag but not significantly more lift than the next-to-full flap setting
because you need lots of drag to be able to adjust the approach angle of descent
eg at London Heathrow a few years ago a BA Airbus had all engines stop on the approach due to fuel icing
the captain reduced flap from full to what I call here next-to-full
the drag was reduced without the lift reducing, and all 350? lives were saved
(if the lift had reduced with the flap reduction a crash was certain)

Not neccessarily. When you´re descending and reduce drag, airspeed increases, what will compensate the lift reduction. The procedure is normal since L/D ratio is lower with full flap, so if you don´t have any thrust you need to improve the L/D ratio as much as posible

I´m almost sure about this because I fly RC planes, and I like experimenting. Slowest posible leveled flight almost stalling (that´s the target, but it frequently stalls ) is one of my favourite maneouvers. With full flap deployment you need higher throttle positions because drag is higher, but to keep a leveled flight as slow as posible, the best is with full flap deployment even if it requires higher throttle positions due to the increased drag. The almost part is because this obviously will depend on each plane and design, but I´m almost sure while it´s properly designed, the rule should remain constant.

[rjsa]

That makes as much sense as a football bat. Then again, so do calls to move from one ground effect solution to another ground effect solution in order to affect something aerodynamically that cannot be affected aerodynamically.

If we're going to wish upon a star, can we at least aim for something a bit more substantial than increased overtaking? Think of the children!

Actual screens from Williams' design office

http://a.yfrog.com/img850/8106/hcjw.png
http://a.yfrog.com/img826/4559/szg.png

That's a real F1 car, and every blue area you see represents a negative pressure coefficient caused by the Venturi effect.

http://i.imgur.com/8bBTIZX.jpg

Again the random web images. You don't know the test conditions and parameters.

Here one for you, from your youtube guy:

[bhall II]

So there...

Again...

We have a problem here. I know you're both wrong, and I've presented an exhaustive and objective list of the reasons why. Yet, it's had no effect.

And yes, as you said those devices would lead to enormoous amounts of downforce... if given enough room to develop them. Same as wings, what´s the difference?

That´s the reason this is F1, not CanAm. There are rules to limit development and total downforce. Those rules wich today limit wing size, placement, rigidity, etc. would also limit downforce of those devices, but they would trade downforce from wings, with downforce from floor/GE, wich will result in cars with same downforce as today (or more, or less, what you prefer, that´s dictated by the rules) but less problems with dirty air.

This statement totally fails to recognize that reducing the impact of "dirty air" in the manner I described would require the complete standardization of the chassis, from the leading edge of the front wing to the trailing edges of the rear wing end plates. Otherwise, development of any sort would rapidly adopt characteristics that progressively advance toward an ever-greater vulnerability to disruption by "dirty air," because that's exactly what it means to develop a Formula One car: you make use of everything. As sure as the fact that we will all one day die, it's inescapable.

Again the random web images. You don't know the test conditions and parameters.

And this betrays a complete inability to understand that a pressure coefficient is a pressure coefficient is a pressure coefficient is a pressure coefficient. We know how these things work. There's no mystery. There's no ambiguity.

Whether it's accepted or not, it will not change.

I'm fully aware that I'm easily frustrated and perhaps too quick to lash out with an overly riposte reply. I apologize. But, just try to imagine being involved in something like this...

"The sky is blue."

No, it's truck.

"-----"

I can't wrap my head around it. So, let's just agree to disagree, shall we?

[Andres125sx]

So there...

Again...

We have a problem here. I know you're both wrong

We poor ignorants....

And yes, as you said those devices would lead to enormoous amounts of downforce... if given enough room to develop them. Same as wings, what´s the difference?

That´s the reason this is F1, not CanAm. There are rules to limit development and total downforce. Those rules wich today limit wing size, placement, rigidity, etc. would also limit downforce of those devices, but they would trade downforce from wings, with downforce from floor/GE, wich will result in cars with same downforce as today (or more, or less, what you prefer, that´s dictated by the rules) but less problems with dirty air.

This statement totally fails to recognize that reducing the impact of "dirty air" in the manner I described would require the complete standardization of the chassis, from the leading edge of the front wing to the trailing edges of the rear wing end plates. Otherwise, development of any sort would rapidly adopt characteristics that progressively advance toward an ever-greater vulnerability to disruption by "dirty air," because that's exactly what it means to develop a Formula One car: you make use of everything. As sure as the fact that we will all one day die, it's inescapable.

So a device less sensitive to dirty air than wings will evolve to a situation where it´s more vulnerable to dirty air than wings... Might your eminence explain this for us poor mortals?

[mrluke]

All that Bhall is really saying is it doesn't matter what you change all of the cars too, it is only the differences between the cars that leads to overtaking.

And as we have seen overtaking for overtakings sake doesn't add anything to the show.

[bhall II]

Might your eminence explain this for us poor mortals?

No one particularly cares about how this works in isolation...



No one particularly cares about how this works in isolation...



No one particularly cares about how this works in isolation...



And no one particularly cares about how this works in isolation...



Why? Everyone is too busy caring about how it all works together...



...because it has to be seamless if a team has legitimate aspirations to compete for World Championships. It's also the aspect of performance where "dirty air" does far and away the most damage.

If this was a problem that could be solved, the 2009 rules would have affected at least a shred of change, and it would have been apparent immediately, because the concepts were brand new and unrefined. They were shifted more toward ground effect by rule; double-diffusers reinforced this by accident; the return of slick tires dramatically increased mechanical grip; and most teams had push-to-pass KERS functionality. The stage was set.

So, why did overtaking actually drop? And what makes you think trading one ground effect solution for another ground effect solution is going to help when it can't possibly address the systemic issues in play??


Remember: most upwash comes from under the car, through the diffuser, and venturi tunnels would be no different

I recognize that most of this this is probably counterintuitive, and, frankly, I can't necessarily blame anyone for being skeptical. No fans of any sport are more ill-served by its leadership and "the specialized press" that covers it than those who follow F1. Logic is like a foreign language.

[Just_a_fan]

The neutral centre section of the front wing was supposed to aid in overtaking by removing the bit of the wing that was most influenced by the dirty air. What happened? The teams designed front wings and under-nose structures specifically to make the neutral section produce downforce. Very clever, you say, but it put them right back where they were previously.

The Law of Unintended Consequences strikes again!

[bhall II]

I think that was probably negligible when weighed against gains to underbody downforce enabled by a high nose above the neutral center section...

[Andres125sx]

So, why did overtaking actually drop? And what makes you think trading one ground effect solution for another ground effect solution is going to help when it can't possibly address the systemic issues in play??

Basically because I don´t want to trade one GE solution for another GE solution, but a wing based solution for a GE based solution.

Anycase GE is just an idea, the target is to reduce dirty air problem and you´ve stated yourself there are solutions wich would reduce the problem. Let´s talk about that instead of explaining why this or that solution will never work. I think nobody is defending a particular solution, we only want to discuss about how to reduce the problem as much as posible

[rjsa]

Again the random web images. You don't know the test conditions and parameters.

And this betrays a complete inability to understand that a pressure coefficient is a pressure coefficient is a pressure coefficient is a pressure coefficient. We know how these things work. There's no mystery. There's no ambiguity.

Whether it's accepted or not, it will not change.

I'm fully aware that I'm easily frustrated and perhaps too quick to lash out with an overly riposte reply. I apologize. But, just try to imagine being involved in something like this...

"The sky is blue."

No, it's truck.

"-----"

I can't wrap my head around it. So, let's just agree to disagree, shall we?

No there isn't any ambiguity. But just posting images that seem to suit you OPINION of how things are supposed to work do not make them a fact.

I give it to you that you are very good at putting together colorful illustrated posts - and it seems you might me the leader of your school's debate team - but when it gets complicated the fluid mechanics knowledge lacks. So may be you don't have it as figured out as you think you do.

What I'm failing to understand is in your opinion what is the solution. Because you picked arguments with everyone presenting ideas but I can't see the picture of what you propose.