Dirty air sensitivity and regulations

[wesley123]

Sure, but do you really think FIA and/or Bernie took the best decisions lately?

They have been going around in circles lately.

I can´t agree with this route, now the problem is even bigger, because aero problem is still here, but there are new problems due to this absurd rules.

The aero problems would always be there. Although I do agree, the aero has been shadowed by tires, fuel saving and DRS. Why should you even bother trying to overtake when you can drive past in the DRS zone? There is absolutely no reason to even attempt to overtake.

That´s a different approach for the same goal I´m proposing, improve efficiency

I agree on this one. F1 should aim more at efficiency. And not the aim they have now, it needs to be much stricter. The thing is, with the fuel flow limit they have now, it can easily be overcome by the driver saving fuel, thus it hardly is of any concern. Apply a 50L/hr limit and it would become an issue that needs to be overcome. This isn't a limit that can be overcome by fuel saving, no, some serious effort needs to be put in to save that much fuel, and that includes cutting drag(and thus, reducing downforce).

Ground effects was never phased out,

phased out was the wrong term I used there. I meant strictly limited. In pretty much all racing classes the diffusers are very small and often a stock piece.

Delta wing uses ground effect for its downforce, none of the horror crashes discussed in this thread have occurred to it yet.

The Delta wing doesn't even come close to the numbers that F1 cars, LMPs, indycars etc. etc. make. The percentages they claim from their underbody is because they generate almost no downforce from the rest of the car. The Delta wing was built around this whole idea. Less weight, Less drag, Less downforce, Less power, same speed.

I also don't think the Delta Wing even came in a situation of dangers i named.

[JDC123]

Hy there,

Something possible??

Maybe Haas built a "dirty air" car?
If you see a haas car in the midfield they are driving like the others in free air.

Jm2C

There is no such thing as a 'dirty air' car. An aerofoil will perform worse in turbulent air due to unpredictable inertia forces that cause premature flow separation from the wing surfaces. This is a scientific fact. There is absolutely no way you could design a wing to perform better in turbulent conditions as opposed to 'clean' laminar conditions.

[NutritionFact]

Okay, sience make the rulez...

[JDC123]

Okay, sience make the rulez...

I have explained the science as to why it fundamentally is wrong......

[hurril]

Okay, sience make the rulez...

I have explained the science as to why it fundamentally is wrong......

I don't think you're being entirely fair here. Clearly you'd build a car that is supposed to go around a track _all alone_ differently to one that has to deal with turbulent air. It's not going to be so much about dealing with turbulence as much as it is not going All In with very sensitive aerodynamics. It's going to be wasted time or effort.

[Raleigh]

There is no such thing as a 'dirty air' car. An aerofoil will perform worse in turbulent air due to unpredictable inertia forces that cause premature flow separation from the wing surfaces. This is a scientific fact. There is absolutely no way you could design a wing to perform better in turbulent conditions as opposed to 'clean' laminar conditions.

No, but you can make a car that will perform better in dirty air vs a car that is optimized for running in clean air (not that I'm suggesting this is what Haas have done).

As a rule, the simpler the aero the less performance will be lost by running in dirty air. A plain 2 element front wing like you'd find on a GP2 car may not generate the same downforce as an F1 front wing with it's 4-6 elements and finely tuned details, but the less complex wing retains most of its performance even if you're running right behind another car.

Indeed, you could probably design a simple wing that outright outperforms an F1 front wing when the car is running in dirty air (of course a car with this wing wouldn't be as fast as the F1 car in clean air, which is why teams don't do this). This contributes to racing frequently being closer in lower formulas than in F1, it's easier to follow another car.

Different types of aero also suffer different amounts from running in dirty air. Downforce from the floor will be less affected than downforce from the wings, and the front wing suffer more than the back wing. This is why F1 cars start understeering as soon as you get close behind another car, they keep most of the rear downforce but you lose the front end.

[rayden]

There would be no reason to design the car like that though.

You would be giving up far too much pure performance needed over the 90% of time that you are not in turbulent air.

You cannot make compromises like that at this level.

[trinidefender]

There is no such thing as a 'dirty air' car. An aerofoil will perform worse in turbulent air due to unpredictable inertia forces that cause premature flow separation from the wing surfaces. This is a scientific fact. There is absolutely no way you could design a wing to perform better in turbulent conditions as opposed to 'clean' laminar conditions.

No, but you can make a car that will perform better in dirty air vs a car that is optimized for running in clean air (not that I'm suggesting this is what Haas have done).

As a rule, the simpler the aero the less performance will be lost by running in dirty air. A plain 2 element front wing like you'd find on a GP2 car may not generate the same downforce as an F1 front wing with it's 4-6 elements and finely tuned details, but the less complex wing retains most of its performance even if you're running right behind another car.

Indeed, you could probably design a simple wing that outright outperforms an F1 front wing when the car is running in dirty air (of course a car with this wing wouldn't be as fast as the F1 car in clean air, which is why teams don't do this). This contributes to racing frequently being closer in lower formulas than in F1, it's easier to follow another car.

Different types of aero also suffer different amounts from running in dirty air. Downforce from the floor will be less affected than downforce from the wings, and the front wing suffer more than the back wing. This is why F1 cars start understeering as soon as you get close behind another car, they keep most of the rear downforce but you lose the front end.

Please stop propagating this myth. Running a more complex wing (a wing with more elements) does not mean it will be worse running in turbulent air. It is a fallacy. It can be worse but at the same time, it can be better.

What multiple elements allows a wing to do is run at higher alpha levels (angle of attack to the apparent airflow direction {due to other cars or the airflow moving over objects a wing will see an apparent airflow, I.e. Not necessarily the same direction airflow as a different area or wing on the car}). Allowing higher levels of alpha allow for much higher Cl (coefficient of lift) values at the expense of very high Cd (coefficient of drag values). Since downforce is still king, for the most part, in F1, the designers will trade the extra drag for downforce in most cases.

What really controls how the front wing operates in turbulence is down to many other variables that weren't mentioned. Some of these are:
a. The overall camber of the wing
b. The camber and shape of each element
c. The size of the slot gaps between each element, usually the larger slot gaps will mean a lower sensitivity to airflow changes but lower maximum Cl levels
d. How close the wing is run to the ground, as the front wings are partial diffusers in their operation and function as such.
e. Vortex generators, strakes and the like which help to keep flow attached to the underside of the wing.
And many more.

A 2 element wing if pushed as hard (as close to its partial or full stall region) will actually stall worse than a 4 or 5 element wing. This is because on a 2 element wing it is very easy for a partial stall region to quickly spread forward along the chord of the wing and severely degrade performance. On a more complex wing as the rear portion stalls the slot gaps help to stop the spread of the airflow stalled region from spreading. Therefore while part of the wing will still stall, it will actually lose less downforce than a 2 element wing.

When it comes to general wing or individual wing element camber, the designers can go many different roots (pun?). Variables such as how much camber is run and where along the wing the point of maximum camber is placed partially dictate the stall characteristics of a wing. Designers can choose to be more safe and go with a design that has a wider operating speed and angle (more effective for a car that consistently runs in dirty turbulent air) or for a design that has very high Cl numbers but will deliver it over a smaller range of angles. This second design philosophy will provide more peak downforce however once the wing starts stalling the stall region will spread very quickly.

So please, stop spreading this "simpler wings = more stable downforce" nonsense.

Thank you and good night.

[Nowhereman]

Boy were you wrong...

[Raleigh]

That's not what I wrote at all...

As I said, the reason why F1 front wings suffer so badly from running in dirty air is they are so complex and rely on such finely tuned airflow to generate their impressive peak downforce.

Which complexity is more down to the myriad vortex generators, strakes, airflow conditioners and precisely calculated aerofoil cross-sections rather than being tied to the number of main elements in the wing. You could make a simple wing with 6 main elements or a very complicated and finely tuned 3 element wing.

Very finely tuned airflow = complex wing = narrow range of peak performance = poor performance in dirty air.

And, yes, of course no team would sacrifice overall lap-time for stability running behind another car (again, I wrote that in the original post), you've got to be able to catch the car ahead before you can think about overtaking.

[ChrisDanger]

A more complex wing (or at least one that maximises downforce) creates a bigger wake than a simpler (smaller downforce-producing) wing. I would think it's the smaller wake that makes it easier to follow closely, not necessarily that a simpler wing is less sensitive to turbulence.

So I doubt this will ever be true:

Indeed, you could probably design a simple wing that outright outperforms an F1 front wing when the car is running in dirty air...

[trinidefender]

That's not what I wrote at all...

As I said, the reason why F1 front wings suffer so badly from running in dirty air is they are so complex and rely on such finely tuned airflow to generate their impressive peak downforce.

Which complexity is more down to the myriad vortex generators, strakes, airflow conditioners and precisely calculated aerofoil cross-sections rather than being tied to the number of main elements in the wing. You could make a simple wing with 6 main elements or a very complicated and finely tuned 3 element wing.

Very finely tuned airflow = complex wing = narrow range of peak performance = poor performance in dirty air.

And, yes, of course no team would sacrifice overall lap-time for stability running behind another car (again, I wrote that in the original post), you've got to be able to catch the car ahead before you can think about overtaking.

You actually did say it,
"As a rule, the simpler the aero the less performance will be lost by running in dirty air. A plain 2 element front wing like you'd find on a GP2 car may not generate the same downforce as an F1 front wing with it's 4-6 elements and finely tuned details, but the less complex wing retains most of its performance even if you're running right behind another car.

Indeed, you could probably design a simple wing that outright outperforms an F1 front wing when the car is running in dirty air (of course a car with this wing wouldn't be as fast as the F1 car in clean air, which is why teams don't do this). This contributes to racing frequently being closer in lower formulas than in F1, it's easier to follow another car."

Flow conditioners and strakes can be use to clean up turbulent (many times referred to as dirty) airflow or they can be used to change the direction of airflow.

Vortex generators can also take unstable airflow or airflow that has a tumbling motion and give it a swirling vortex motion. This won't function the same as clean flow but it can be used all the same.

The complexity of a wing is not what decides it's sensitivity. It is simply the variables I mentioned earlier such as slot gap size, camber, ride height and the one that sums all up and takes all other factors into account is how close the designers run the wing to its stall angle for the predicted conditions and other factors; density altitude, balance of the car, driver feeling (still very important) etc.

[turbof1]

The complexity of a wing is not what decides it's sensitivity. It is simply the variables I mentioned earlier such as slot gap size, camber, ride height and the one that sums all up and takes all other factors into account is how close the designers run the wing to its stall angle for the predicted conditions and other factors; density altitude, balance of the car, driver feeling (still very important) etc.

I think that's the key: as long as downforce is that much of a premium teams basically would increase it for any drag penalty, your camber, slot gaps, etc will be pushed to the limit, with increased probability on stalling due running in turbulent air. Drag penalty is correlated to engine power too: the more engine power you have, the easier it is to take the extra drag in return of more downforce, and if the latter limited enough the more sensitive your aero will become.

Remember the ground effect cars of the late 70's/early 80's? It might not look like that at first sight, but the complexity of the underbody was nothing to sneeze at. Yet they produced a tremendous amount of downforce while cars where still able to follow eachother rather closely.

EDIT: very nice article with unexpected results: http://www.espn.co.uk/f1/story/_/id/151 ... means-2017

I suddenly realized this is the Haas VF16 Ferrari topic. Gents, how about I move or split this topic?

[PlatinumZealot]

The More air manipulation from front to back the more sensitive the aero, but that a more sensitive car can still have more down-force than an insensitive car in traffic. RedBull 2009 to now.

[hurril]

The More air manipulation from front to back the more sensitive the aero, but that a more sensitive car can still have more down-force than an insensitive car in traffic. RedBull 2009 to now.

Right, but what's being alluded to here is probably best described as aero volatility. The down force could be a magnitude better for clean air than for dirty (which could still be, as you say, better than that of a shitty car.) Still, such a big difference is going to mean something for the drivability.