Explain clever people :P

[PNSD]

Ok, anyone noticed one of Toyota's midwings is a delta delta wing? and the other a swept wing..? :S

Delta wings feature on supersonic aeroplanes, ie Concord,Eurofighter.

Now, who can explain flow seperation at subsonic levels?

I understand the advantages to a fighter plane or supersonic plane at supersonic speeds the leading edge is behind the shockwave created by the nose of the aircraft.

So yeah.. please explain the swept wing on the car, then the delta wing lol.

[flynfrog]

the areo guys spend high school building this?

[PNSD]

Niceone.

So care to explain the effects of a delta wing at subsonic speeds ?

[Tp]

Well the reason they are swept back is due to the fact that supersonic shockwaves have a nasty habit of sitting on the trailing edges of the wings, causing the ailerons to jam.

To solve this they had to remove the ailerons and the whole wing had to move. Or you needed a delta wing. The problem with delta wings is the cross section is unlike that of an ordinary commercial plane. It hasn't got that curved upper plane - the way plane's produce lift. So supersonic planes were designed to produce vortices on the upper surface to create lift.

[Tom]

I often wondered why F1 guys don't use swept back wings, have you ever noticed that slower aircraft, like Herculese, have straight wings, while some, like the Phantom I think, have swept wings. Surely the F1 teams have noticed this, I assume it gives a reduced frontal area (therefore reducing drag) while keeping the same surface area of wing producing similar lift. Any answers?

[R1ceboy32]

F1 cars don't use swept wings since they don't travel close to the speed of sounds...yet The swept wing essentially reduces the wave drag that is normally associated with transonic and supersonic flight. The sweep of the wing tends to reduce the wave drag by reducing the apperanent thickness of relative to the airflow. The problems with swept wings is that during low speeds, the air will start to travel spanwise reducing the amount of lift a wing will generate.

[Tom]

Ah, I did wonder if the speed was too low, esspecially as you need downforce only in slow corners.

[PNSD]

This is the reason i was confused.

I first noticed them at Monaco...

Hense me asking what do they do at substantially subsonic speed ?

[kilcoo316]

Well...

A designer looks for downforce in a corner, and indeed looks for less downforce down the straights = less drag.


Having a rearward swept wing will result in reduced downforce on the straights, but will result in increased downforce on the inside half of the wing in corners, helping to reduce car roll and keeping the aerodynamic platform more stable.

If the wing was forward swept, there would be the same downforce reduction on the straights, but increased downforce on the outside side of the wing in the corners, increasing yaw.


F1 cars have yaw rates of up to 50deg a second, so it is an avenue worth pursuing.

[Tp]

Why don't they just use a shorter mid-wing then?

[DaveKillens]

First off, the relative air velocity is nowhere close to the speed of sound, so that's really not something to deal with.
http://selair.selkirk.bc.ca/aerodynamic ... Page5.html
The wings are symmetrical about the centerline of the car, so there is no induced yaw, or roll.
On the Toyota winglets on the airbox, there are currently three elements, as PNSD described.
http://www.f1racing.net/en/photolarge.p ... &catID=110
These elements are so short that there's really no issue with spanwise flow or typical aircraft wing issues. But the turbulence coming from the cockpit area and around the airbox has a huge influence on when it eventually flows back to the rear wing. We now see some form of tabs, or horns, or winglets on the chassis nose, cockpit area, and airbox cover in almost all teams. The goal is to allow the rear wing deliver maximum downforce at minimum drag. And that's where these wonglets come in, because they not only contribute some downfoce by themselves, but more important, condition and straighten the air so that when it arrives at the rear wing, it is flowing straight and smooth and in a method allowing optimum conditions for the rear wing.
The air flowing close to the airbox has different turbulence an ddirections than , let's say, six inches away from the airbox. So although a straigh and regular wing section is OK, the design does not address different conditions close to the airbox, or a little distance away. And that's what these odd shaped wings do. They have different chord and size, determined by what conditions they are operating in, and the results desired. Obviosly, the airflow very close to the airbox is more turbulent than a few inches away, so a broader chord wing at the middle addresses that. Same with the shape, which co-incidently winds up appearing swept back.
Each team has the same problem, turbulence around the airbox and cockpit, which has the potential to reduce the effectiveness of the rear wing. So each team have strakes, or winglets, or whatever installed to deal with this problem. Because of different flow patterns, because basically each car has different philosophies on air management, we see different shapes on the wings on the airbox. And trust me, each team tries what the competitors are doing. When McLaren came out with the unique horns, I can guarantee you that each team fabricated up horns and ran them through the wind tunnel to see if they were effective on their car, and could be used.
In summation, the winglets on the Toyota possess the shape because the air flowing around the airbox is moving in different directions and velocity near the surface, and in a different manner further out, and further out. The wings are designed to accomodate the different requirements at different distances away from the airbox.

[Ciro Pabón]

Dave, I'm not sure if this can induce yaw or roll: the wind speed of the "inner" part of the wing is slower than the wind speed of the "outer" part of the wing.

As an (almost) extreme case, I take the Repsol curve in Catalunya.

This curve has (according to my own restitution) a 35.4 m radius and 146 degrees of deflection (deflection is the change in direction of the car or the angle of the curve). This means the length of the curve is 90.0 m.

If the car is at 100 kph, or 27.8 m/s (according to Brembo), the wing is 2 m wide and you drive exactly by the centerline, this happens:

- The center of the car travels at 100 kph. The car travels 90 m in 3.2 seconds.
- The outer tip of the wing travels 92.6 m in the same 3.2 seconds. The speed of the wing outer tip is 102.8 Km/h
- The inner tip of the wing travels 87.5 m in the same 3.2 seconds. The speed of the wing inner tip is 97.2 Km/h

The difference in air speed between the inner and outer wing tips is 5.7 Km/h or roughly 6%. I wonder if this creates enough yaw or roll that you can actually feel...

Do you know how much downforce difference this creates? I believe it should be proportional to wind speed, but then you have to integrate over the entire wing.

Anyway, I believe this effect helps the car to turn: the inner wheels have less downforce than the outer wheels. This should help the car to take the curve. There is also less drag in the inner part of the wing, a fact that doesn't help the car to turn, but this is a secondary effect.

It creates some deleterious roll: as the car has more downforce on the outer part of the wing, it should tend to roll towards the outside of the curve.

[DaveKillens]

Point well taken Ciro, logical and I believe it. But then again, the same rules apply to the front and rear wings, and any flip-ups.
Let's go back to the airbox winglets. In a turning scenario they would also be slightly masked by the front portion of the air intake, the outside root should be shrouded, and receive very little airflow, and if much, quite disturbed airflow along the surface of the airbox. The root of the inside wing would receive cleaner air, and of a higher pressure than it's opposite location.
But any effect would give a roll tendency to the outside, and apply more load on the outside tires, and less on the inside, which already have inertia unloading them. I don't think that is as desirable as having the opposite effect, making the inside tires carry more cornering force.

[Scuderia_Russ]

the areo guys spend high school building this?

The first thing I saw when I saw that was it reminded me of the car Homer built for Unkie Hurb before he went bankrupt.

[mep]

Very interresting discussion.

I wonder if someone here realy understands the funktion of this
elements totally.

The first wing has a profile to create downforce.
The second is propably there to guide the air back
in a straight line and maybe to the rear wing.

But the wings have al more or less a angle of attack
of zero. So it's hard to believe that they will guide
air down to the rear wing.
They are more there to reduce the vortex from the airbox to
reduce drag.

It's other than an the RedBull where it's clearly visible
that they guide the air down to the rear wing.
Don't forget that the air box is much higher than the rear wing.
So they must have a positive angle of attack to guide the air down.

viewtopic.php?t=3014
(I have a RedBull picture here, I had the chance to take
a close look at some of the cars and I think that the teams
follow different types of philosophys in designing the airbox wings.
Some try to create downforce by the airbox wing itself and
the other try to create a downwash to the rear wing
to produce the downforce there)