Ground Effect - Bring It Back

[Just_a_fan]

Some people already complain that the current cars sound like vacuum cleaners - with fans on them lifting dust and stones off the track they'll behave like vacuum cleaners too!

[SectorOne]

Some people already complain that the current cars sound like vacuum cleaners - with fans on them lifting dust and stones off the track they'll behave like vacuum cleaners too!

Which is good No more excuses about dirty track, all they have to do is do a lap each and the track is cleaned

Which got me thinking about rain, what effects did the brabham have on a wet track?

[rjsa]

Anyway, any effect that the difference of density in the wake of a F1 car under mach .3 will make in downforce is negligible.

And that's exact the point of an assumption or approximation.

We are not talking P51s flying at mach 0.75.

I was just being pedantic - this is, or rather used to be, a technical forum. Some others on here may not know that assumptions and simplifications are used to make the calculations easier. They don't use these things in their fanboy threads

Ok, sorry I got it wrong.

[Andres125sx]

Yes, you can absolutely reduce the effects of "dirty air" by limiting a wing's AoA, but you will also dramatically reduce downforce unless the rules are also amended to allow huge wings to make up the difference.

You´re missing the point of the thread, it´s not reducing AOA to increase WS, but reducing wings to increase use of GE´s

[rjsa]

...

Ok, how do you do it? Please note, F1 cars are already in ground effect. They don't run the cambered undersides and skirts of the classic "ground effect cars" but they still make use of ground effect. Any wing placed within its own chord length of the ground will experience "ground effect" and the closer you run it - to a point - the more the effect increases the downforce produced.

Now, you could go back to tunnels and skirts but I'm not sure how else you could implement "ground effect" and have a hope of running close together.

Yes, but only by very hard manouvering around the rules.

The diffuser only exists because the rules were badly written back in the 80s. Rules say floor must be flat between the axles. That because floors never went backwards than that and who in hell would raise the nose, right? And the insane rake angles.

Now you're about to re-write the rules, force a pair of standard tunnels on the sidepods or even make the diffuser go forward and bring it's choke point on top of the mass center. Now just tune back the wings. Smash those almost flat, two elements max. Wider and lower rear, bring the front ones within the wheels where they are supposed be.



And enforce minimum hide height, kill the rake and even get rain racing back in the process.

[Andres125sx]

F1 use high cambered wings because they only care about downforce, drag is a minor problem so they use what create the highest downforce, high cambered wings

No, they use highly cambered wings because they have limited span available to them. The rules allow a relatively small box in which to fit the wing. In this situation, you make most downforce by making the chord as long as possible. In a restraining box, the only way to do that is to add camber. Lots of camber.

That´d be true if teams have a target downforce, so if a bigger box would be allowed then they´d use less cambered wings, but I think it´s not the case, teams look for the highest posible downforce because that´s the main factor to be fast.

So I don´t think with a bigger box they´d use less camber, they simply would create a lot more downforce using same camber on a bigger wing. The target is not an specific amount of downforce, but creating max posible downforce from slow speed without stalling at high speed. Well, maybe some stall at max speed is good to reduce drag but that´s a different debate.

Actually downforce can be created even by a flat surface with an angle of attack, so you don´t even need an airfoil to create downforce

Yes, but the amount of downforce produced by a flat plate is not as much as a cambered wing, or rather it's not nearly as efficient. An angled flat plate will produce some quite spectacular edge vortices that will make the air behind very unpleasant.

Agree, I was not defending the use of flat surfaces, it was only an example to explain high cambered wings are not a must to create downforce, downforce can be created from many different ways

The speed wich F1 cars travel are anything but slow, for example a huge Boeing 747 and its 100 tons take off at around 230km/h, depending on the TOW (take off weight), so no the airspeed F1 cars travel are not slooooooooow as you say, they´re quite fast

Go back and think about the respective spans and areas of the wings of F1 cars and 747s. Also, remember that F1 cars need maximum downforce in corners - the point on the track when they are at their slowest. Look at a 747 when it is at its slowest speed (that's when it's landing). What do you see? You see big multiple element flaps that create, you guessed it, a highly cambered wing. The turbulence behind a landing 747 is so bad that following aircraft are kept several miles away.

Yes, but not because of dirty air caused by the aero design, but because of the turbines

[Andres125sx]

I
This is where "dirty air" and performance differentiation converge. A trailing car will always tend to have worse aerodynamic efficiency than a car in "clean air." So, a trailing car will always tend to need a non-aerodynamic advantage in order to overtake, which the current formula doesn't allow. Hence, DRS and/or futility...

The answer is, quite simply, to have active aero. Allow the car behind to adjust its wings to give it more downforce in the dirty air. This negates the effect of being close to the other car in corners and allows the driver to close up to the car ahead. Then it's down to balls, and late braking at the end of the next straight...

That´s very similar to an idea I posted on the thread PZ opened to talk about fan cars whose fan only work when chasing a car. I said it could be better some sort of inverted DRS, it would be more of a DIS (downforce increase system). Instead of reducing drag in straights, it´d be better increasing downforce in corners so the trailing car can get close to the car in front before the straights, and then use slipstream

But I´d also prefer full active aero wich allow higher AOA when chasing a car to compensate dirty air

[rjsa]

I
This is where "dirty air" and performance differentiation converge. A trailing car will always tend to have worse aerodynamic efficiency than a car in "clean air." So, a trailing car will always tend to need a non-aerodynamic advantage in order to overtake, which the current formula doesn't allow. Hence, DRS and/or futility...

The answer is, quite simply, to have active aero. Allow the car behind to adjust its wings to give it more downforce in the dirty air. This negates the effect of being close to the other car in corners and allows the driver to close up to the car ahead. Then it's down to balls, and late braking at the end of the next straight...

That´s very similar to an idea I posted on the thread PZ opened to talk about fan cars whose fan only work when chasing a car. I said it could be better some sort of inverted DRS, it would be more of a DIS (downforce increase system). Instead of reducing drag in straights, it´d be better increasing downforce in corners so the trailing car can get close to the car in front before the straights, and then use slipstream

But I´d also prefer full active aero wich allow higher AOA when chasing a car to compensate dirty air

That's been tried before, the 2009 and the active front wings.

[Just_a_fan]

So I don´t think with a bigger box they´d use less camber, they simply would create a lot more downforce using same camber on a bigger wing. The target is not an specific amount of downforce, but creating max posible downforce from slow speed without stalling at high speed. Well, maybe some stall at max speed is good to reduce drag but that´s a different debate.

No, they'd design for a better L/D i.e. excellent downforce but with less drag. That way they're quick in the corners and the straights. There's only so much downforce you can use before you start to create issues for the driver and the tyres. Tyre grip increase is not linear with downforce - you can't just keep doubling downforce and expect a doubling of grip every time.

Yes, but not because of dirty air caused by the aero design, but because of the turbines

The reason is "wake turbulence". On approach the engines are running at little more than idle because they are trading height and speed in such a way that both reduce as they approach touch down. The huge lift generated by flaps and angle of attack causes huge turbulence behind the aircraft.


See how the vortices running off the back of the flap's outer end runs back to the large vortex pattern in the cloud behind? That big swirl in the cloud is caused by the wings working the air very hard.

Even wings that are in a "clean" configuration and that have fairly high aspect ratios cause wake turbulence


A lot of research has been carried out on wake turbulence because it is has a huge safety implication. Here's a great image from some of the research.

See how the vortex is formed by the end of the wing? See how little camber there is on the wing? This vortex has two effects:
1. It reduces the efficiency of the wing producing it - it effectively reduces the wing span by creating a downwash on the wing's upper surface. That's why racing cars run endplates and why modern passenger jet aircraft have vertical winglets on them.
2. It creates big turbulence issues for following aircraft - if you were to fly down the vortex you'd have massively different angles of attack on your wings depending on the direction of the vortex. The results of this can, and have been, fatal for smaller aircraft following large aircraft.

Any system that generates grip by the use of aerodynamic manipulation in a small vehicle like a car will produce turbulence - you can't avoid it.

[Tommy Cookers]

wake turbulence 'research' is just hype (because WT is inherent)

the real issue was the authorities lax regulation
(for 35 years the seperation rules sorted aircraft into 3 categories - <200,000 lb, 200,000 - 600,000 lb, and over 600,000 lb and ....
only when the number of aircraft near and over 600,000 lb had increased about 100 fold problems were the rules extended)

[Andres125sx]

That's been tried before, the 2009 and the active front wings.

Yes, but not too hard. I never understood the reason they stopped that approach, it was a good idea, much better than DRS

[Andres125sx]

The reason is "wake turbulence". On approach the engines are running at little more than idle because they are trading height and speed in such a way that both reduce as they approach touch down. The huge lift generated by flaps and angle of attack causes huge turbulence behind the aircraft.

As you said previously, because with approach wing configuration they deploy both LE and TE, so the wing actually is a wing with lots of camber, same as F1.


For landing they need as much lift as posible to reduce landing speed and runway requirements, and drag is not a problem because when landing they need to reduce speed. Similar to F1, they need as much lift as posible with no (too much) worries about drag.

Taking off it´s different and that´s the reason flaps have two different configurations, one for landing with full deployment so wings have a lot of camber, and another to take off with only half deployment so the wing has some camber but a lot less.

If drag is a problem, camber is reduced. When landing it is not a problem so they use as much camber as posible (same as F1) so dirty air/drag/wake turbulence are high

[bhall II]

Yes, you can absolutely reduce the effects of "dirty air" by limiting a wing's AoA, but you will also dramatically reduce downforce unless the rules are also amended to allow huge wings to make up the difference.

You´re missing the point of the thread, it´s not reducing AOA to increase WS, but reducing wings to increase use of GE´s

Oh...

This lateral effect of generating the maximum posible downforce (dirty air) could be minimized if they´re forced to use different airfoils, period.

It seems to me the point of the thread is persistently ignore responses that don't cater to an ill-considered view of reality until somehow a broad consensus can be reached that, yes, we can walk on water if we just try really, really hard.

[Tommy Cookers]

@ Andres

landing flap setting is chosen to give a greater Cd and a so lower lift/drag ratio - because you want to descend
because of this lower L/D ratio you will be unable to climb with landing flap (more or less)
so takeoff flap is chosen to give a greater L/D ratio

WT comes from pressure difference above and below wing - ie lift coefficient regardless of how this is achieved
the main difference between landing flap and takeoff flap is the Cd - not the lift coefficient
greater Cd with unchanged lift coefficient should increase wake velocity in direction of car or plane motion (not laterally)

btw
leading edge flap is also used with little or no trailing edge flap (ie first and last stages of flap use)
it gives useful lift coefficient with small AoA and less pitching moment than TE flap and is important in climb

[Andres125sx]

Yes, you can absolutely reduce the effects of "dirty air" by limiting a wing's AoA, but you will also dramatically reduce downforce unless the rules are also amended to allow huge wings to make up the difference.

You´re missing the point of the thread, it´s not reducing AOA to increase WS, but reducing wings to increase use of GE´s

Oh...

This lateral effect of generating the maximum posible downforce (dirty air) could be minimized if they´re forced to use different airfoils, period.

It seems to me the point of the thread is persistently ignore responses that don't cater to an ill-considered view of reality until somehow a broad consensus can be reached that, yes, we can walk on water if we just try really, really hard.

Yes it looks like that, the thread goes about GE, and you keep ignoring that arguing about wings

I said you can use a different airoils to reduce dirty air, but not to compensate the downforce reduction with a bigger wings as you stated, but to compensate it with more ground effects so dirty air would be reduced, wich is the point of the thread