Dirty air sensitivity and regulations

[turbof1]

I have stopped looking at the problem as "combatting dirty air" and just to "being able to race the leading car closer".

A reason why variable geometry has not been considered, could be the difficulty: you'd need actuators more complex then the current DRS ones, and across several aero devices. All these actuators have to be fail-safe.

And of course again: no guarantee it's an actual solution. But that is something you can say about everything. I do wish they tried to test out variable geometry on aero devices.

[bhall II]

You can call it whatever you want; the mechanics are the same.

The great difficulty of active aero, especially in a hyper-competitive environment like F1 where everything is optimized to the Nth degree, is the Herculean task of accounting for flow structures that vary in both size and shape depending on airspeed. The former is intuitive enough to grasp conceptually, but the latter presents a virtual byzantine labyrinth of possibilities that's insanely difficult to understand due to the logarithmic nature of the relationships between speed, pressure, and the forces imparted.

When we see aero rakes attached to the cars, that's what they're analyzing.



Like I said before, it's much easier to make something perform worse than it is to make something perform better. That's why effective moveable aero, be it active like DRS or passive like Red Bull's flexible wings or somewhere in between like McLaren's f-duct, tends to be a concept that reduces downforce instead of increasing it.

[Andres125sx]

The fact that is it still passing through air, even if it is turbulent

Dirty air only reduces efficiency, but aerodynamics are still aplicable

Obviously. But, to what degree is efficiency compromised, and can it be overcome?

Overcome efficiency? Sorry I don´t understand what you mean

Like total pressure, total energy is constant. So, an increase in kinetic energy results in a decrease in potential energy. Ultimately, that means wake turbulence doesn't have a whole lot to offer, regardless of any aerodynamic elements deployed to harness it.

In other words, it's difficult to make a lot of one thing from a little of something else.

Of course, but what is really important is the points of DF the trailing car can get from that potential energy, and the points of DF are the product of that potential energy multiplied by a factor wich is dependant to the car.

If we cannot stop the decrease in potential energy when in a slipstream, we still can modify how much of that potential energy the car will use.

Ultimately, that means wake turbulence doesn't have a whole lot to offer, regardless of any aerodynamic elements deployed to harness it.

I don´t think so, if it would really be regardless of any aerodynamic elements deployed that would mean aerodynamics are almost useless when in a slipstream, when they obviously are not or no F1 car could be close to any other car not even for a single corner. With no aerodinamycs they´d be several seconds slower, on each corner.

They can keep close some time, so DF is reduced but not evaporated, and that means there´s still a good quantity of potential energy.

So if DF (x) is a product of potential energy (y) and the use the car can make of it (z), if you cannot stop that decrease in (y), you still can increase (z) to compensate


Basically this is the reason I think active aero could be used to, at least, reduce the problem. The difficult part obviously is figuring out out to increase aero only when in a slipstream efficiently


Without any other consideration, a fan would be the easiest way, as it does not modify anything phisically and the speed and DF can be modified. But no idea how to do it. A fan wing instead of a fan car has any sense?. I mean, the front wing equipped with a fan. Even if it would need a complete reconsideration of the concept so it only works as a mini fan car. If posible, it could be used without restrictions, as adding tons of DF to the front is not any useful, it only would serve to prevent the car from loosing balance when in dirty air, and that´s one of the biggest problems, it makes the car slower, the front tires degrade quickly, and also force drivers to be a lot more conservative, they cannot attack constantly, so only solving the balance problem the show will improve dramatically I think

Plausible or absurd?

[mrluke]

What is the evidence to show that the "wake" or a loss of downforce is the reason for difficulty in overtaking?

[bhall II]

So if DF (x) is a product of potential energy (y) and the use the car can make of it (z), if you cannot stop that decrease in (y), you still can increase (z) to compensate


Basically this is the reason I think active aero could be used to, at least, reduce the problem. The difficult part obviously is figuring out out to increase aero only when in a slipstream efficiently

That's not how it works.

A wing's camber, angle of attack, and constituent elements are largely a reflection of the prevailing conditions the wing is expected to encounter. Since F1 cars spend more time in clean air than in traffic, and clean-air configurations offer the highest possible performance potential, wings are designed accordingly. The problem is that conditions inherent to wake turbulence can't sustain the aggressive wing settings that are possible in clean air.

In broad, (very) simplified terms, what keeps air flow attached to an aerodynamic surface is potential energy. The more potential energy contained within a packet of air, the more that packet of air can be productively manipulated before it detaches. Because total energy is constant, or conserved, the increased kinetic energy of a turbulent wake means it has less potential energy to keep packets of air attached to a wing element. To wit, the efficiency of a wing is reduced when passing through turbulence, because air flow detaches earlier than it would in clean air.



Increasing AoA would only make the problem worse, like the pilot of a stalled aircraft who pulls back on the stick instead of pitching the nose down. For F1, the corrective action would be to reduce AoA. However, that won't increase downforce, and it's not likely to prevent further losses, because precious little about wake turbulence is consistent. By definition, it's unsteady.

It's possible that deploying flaps to make the front wing larger could help mitigate the problem. But, deploying flaps would definitely have a negative impact on elements downstream.

Again, it's a lot easier to reduce downforce with active aero than it is to increase it.

Random thoughts on a wing equipped with fans...

1. The outer extremities of a car are the worst possible places to add weight.
2. Not that I'd really care, unrestricted fans could potentially become a performance differentiator such that overtaking would be affected by aero the same way it is now, except in reverse. If the idea is less aero, that outcome would make it all pointless. (And the result would still be subject to negation by convergence.)
3. Aero balance can be managed passively. In fact, it is.



The adverse impact of wake turbulence is diminished as you move from the front of the car toward the back. That means front-biased low-pressure zones (pictured above) should theoretically be no worse than evened out by turbulence. In practice, ordinary development makes it a moot point.

What is the evidence to show that the "wake" or a loss of downforce is the reason for difficulty in overtaking?

None exists. It's all anecdotal.

[Andres125sx]

What is the evidence to show that the "wake" or a loss of downforce is the reason for difficulty in overtaking?

It´s called common sense, when you´re trying to overtake and your car suddenly becomes 1 second slower and its balance is ruined (understeer) because of that wake turbulence as drivers complain about frequently... what more evidence do you need?

BTW, I think we all agreed a long time ago it is not the reason, but one of the reasons.

[Andres125sx]

So if DF (x) is a product of potential energy (y) and the use the car can make of it (z), if you cannot stop that decrease in (y), you still can increase (z) to compensate


Basically this is the reason I think active aero could be used to, at least, reduce the problem. The difficult part obviously is figuring out out to increase aero only when in a slipstream efficiently

That's not how it works.

Yes it is how it works, if you cannot reduce wake turbulence you always can increase aero on the car passing through that wake turbulence. Not sure what makes you think you cannot increase car´s aero, as if they would be using all known technologies to create DF. No they´re not, so there´re a lot of options to increase DF.

You´re assuming I want to increase DF increasing AoA of wings, when I´m not. But incrasing AoA is not the only way to increase DF

Random thoughts on a wing equipped with fans...

1. The outer extremities of a car are the worst possible places to add weight.
2. Not that I'd really care, unrestricted fans could potentially become a performance differentiator such that overtaking would be affected by aero the same way it is now, except in reverse. If the idea is less aero, that outcome would make it all pointless. (And the result would still be subject to negation by convergence.)
3. Aero balance can be managed passively. In fact, it is.

1. Who cares, all cars will be the same and laptime lost can be easily compensated if people bother
2. No, the idea is not less aero. This proposal is exactly to avoid reducing aero, but still improving wheel to wheel racing, wich is the main point of this idea. People usually think aero and close racing are incompatible, I think with active aero they´re not and that´s exactly what excites me about this idea, wheel to wheel racing while cornering at 4-5 Gs sounds too good to not try it.
3. That´s not what it looks like when drivers complain about the dificulty to stay in a slipstream, or when they are forced to desist from trying and have to move back 1,5-2,5 seconds to avoid destroying his front tires


So this fan wing idea must not be that absurd if you can only say this about it

[rjsa]

What is the evidence to show that the "wake" or a loss of downforce is the reason for difficulty in overtaking?

None exists. It's all anecdotal.

You can say the same about photons and gravity. And who knows what else.

This feels like a high school debate club. Arguing for the sake of it, with no set objective other than winning the discussion. Or bothering the opponent out of it.

[bhall II]

You can say the same about photons and gravity. And who knows what else.

I disagree with your examples, but I understand your point (especially the part about how silly this whole thing has become).

Even so, the fact remains that no one has an empirical understanding of the relationship between wake turbulence and overtaking. Therefore, no one knows exactly how, or even if, it can be addressed, much less if it can be done in a way that's palatable to those who want to get rid of gimmicks like DRS and fragile tires.

So this fan wing idea must not be that absurd if you can only say this about it

No, I foolishly assumed you would remember previous criticism and understand that it still applies.

Let's just agree to disagree, shall we?

[miqi23]

Even so, the fact remains that no one has an empirical understanding of the relationship between wake turbulence and overtaking. Therefore, no one knows exactly how, or even if, it can be addressed, much less if it can be done in a way that's palatable to those who want to get rid of gimmicks like DRS and fragile tires.

May be they do have an empirical understanding of the relationship between wake turbulence and overtaking, and their opinion is not that important because the politics outweighs their opinions in this instance?

[strad]

What is the evidence to show that the "wake" or a loss of downforce is the reason for difficulty in overtaking?

Hmmmmmm
Ever tailgate a semi at 80 or so?

[Andres125sx]

So this fan wing idea must not be that absurd if you can only say this about it

No, I foolishly assumed you would remember previous criticism and understand that it still applies.

Let's just agree to disagree, shall we?

So no more comments about viability of a front wing with a fan?

If posible, I still think it might be a good option to adjust DF levels when in a slipstream, total DF of the car would be determined by the floor and rear wing (restricted by rules to achieve desired levels) , while the FW would only be tool to keep the car balanced constantly, even if in a slipstream.

I think a fan probably is one of most resistant devices to create DF in turbulent air, and does not cause any dramatic change on the aerodinamic parts behind it as it does not change anything phisically like active wings would do

But I don´t own the technical knownledge to understand if this is posible or not, so I´ll keep asking to those with more knownledge than myself. Sorry Ben but you´re one of those who has already solved some of my doubts (thank you for that btw) so I´m afraid this discussion will continue

[mrluke]

What is the evidence to show that the "wake" or a loss of downforce is the reason for difficulty in overtaking?

Hmmmmmm
Ever tailgate a semi at 80 or so?

Apologies if I was not clear.

Is there any evidence at all to show that the reason overtaking is difficult is down to a loss of downforce?

i.e. Can we show that the difficulty is not caused by:
- reduction in drag
- reduced braking distances
- high corner apex speeds
- track design
- "spec" cars
- Something else?

If we hope to come up with an effective solution we need to first diagnose the cause accurately.

Is it true to say that in 1990 following cars were not affected by a downforce loss whereas in 1995 they were?



Ferrari F1 1990


Ferrari F1 1995


Note that from 1990 there was a continual decrease of overtakes rather than abrupt change in response to rule changes or similar.

Furthermore, can we really say that the aero impact on the following car was the same between 1995 and 2008?

Ferrari 2008

[bhall II]

May be they do have an empirical understanding of the relationship between wake turbulence and overtaking, and their opinion is not that important because the politics outweighs their opinions in this instance?

What's the political benefit to maintaining the status quo? I understand that front runners rarely embrace change of any kind. But, the structure of the sport's governance no longer demands unanimity.

More plausible, in my view, is the likelihood that the sheer multitude and complexity of the variables involved make such an understanding extraordinarily difficult to achieve. Adding to the challenge is the sport's archaic ruleset, as it's resulted in cars that are designed to conflicting standards, because it seems no one recognizes the stupidity of tacking on new concepts to a base that's over 20 years old.

What makes matters of outside perception worse is the widespread, yet largely erroneous, belief that the wings of a F1 car behave like the wings of an aircraft. They don't.

The fundamental functionality of this...


via Simscale

...is virtually identical to that of this:



via Keith Young

(I'm not saying you or anyone in particular is wrong about anything in that regard. I'm mostly just pointing this out for the hell of it.)

[bhall II]

What is the evidence to show that the "wake" or a loss of downforce is the reason for difficulty in overtaking?

Hmmmmmm
Ever tailgate a semi at 80 or so?

I think everyone understands that wake turbulence doesn't do anyone any favors. The question is degree, and it's very easy to exacerbate the problem if rule changes don't reflect a thorough appreciation of the variables.

What was interesting was that by using a scientific approach to the problem it became clear that previous attempts to solve the problem had in reality made things worse.

"Almost all of the attempts to reduce downforce in the recent past have been retrograde in terms of overtaking possibilities and wake behaviour," one member of the OWG said. "If we had wanted to make overtaking chances worse, that was what we would have come up with."