Technical Regulations for 2009-2015

[autogyro]

Your muddling your aerodynamics with your DF again.

[WhiteBlue]

Autounion Type C and D cars (1936-1939) were shaped in the big wind tunnel of the aerodynamic institute of Berlin-Adlershof (Eagle's Court). At that time they focussed so much on reducing drag that moderate winds made the cars go airborne. Germany's second GP champion Bernd Rosemeyer died that way.



F1 was always aero, but not always about high DF or DF at all. A moderate DF is probably best.

[strad]

Man you are grasping and now you're talkin pre war Grand Prix racing not F1
But I will give W/B that..it has been to some degree or other been about aero in the streamlining sense..but not necessarily about downforce.

[Jersey Tom]

This is a funny thread.

[Pingguest]

It would be interesting to see a graph of downforce v engine bhp over the last 15 years.

Please
Don't give him a W/B an excuse to make more graphs, charts and silly statistics,
For the cat that thinks it's always been about high tech should try remembering when Can-Am cars had more power, more speed and more tech.

Aerodynamics are for people who can't build engines.
Enzo Ferrari

or it is for the people who arent allowed to build better engines, like every f1 team.

Aero has always been an huge factor in formula 1. Stating that these high downforce levels causes the less overtaking is rubbish, remember the ground effect cars? I believe those had more downforce, and there was alot of overtaking, so it is an rubbish excuse.

Those ground effect cars generated more downforce than actually necessary: the cornering speeds were mostly a consequence of the tyres. In case drivers slipstreamed and lost downforce, they still had enough to drive around the corner.

[Ogami musashi]

If you increase downforce you always increase drag and wake turbulence. QED

No.

No you don't; First, the drag concerned is the induced drag and oh my god hopefully we can design wings that have not more induced drag with high downforce like we can design wings with no so much downforce and high induced drag.

How? Low Coefficient of lift and high AR are the way to go.


To go to the main goal (showing you high downforce is not necessarily equivalent to bad wake and low DF to good one) the effects of the wake are far more than a question of strength.

This strength is dependent on so many parameters that it is too long to explain here why but i'll go for quoting them at least:
-Wingspan circulation (Velocity of the spanwise flows)
-Wingspan loads (distribution of lift)
-Finess
-Vortices combination
-Vortices direction
-Vortices developpement, roll up and decay



And yet, all of those parameters of strength do not tell the whole story of effect on the following car;

Indeed the strength of the vortex can be of moderate impact on the following car while the actual kinematics of the vortices is far greater.


That is to say that no..wake turbulence is not directly related to lift/df...it could be, that is, you could see a degradation of wake turbulence with increase in downforce, but that would not be because of increase in downforce, but by modification of some fundamental parameters (i quoted).

So your QED is not so much a QED.


To conclude that, i'll quote you measures to decrease vortices that exists:

-Use big surface, low Coefficient of lift and/or high Aspect ratio (hello liners, hello ground effects!)
-Increase virtually Aspect ratio (Hello endplates, C shaped wings!)
-Use counter annulation vortex generation (studied since 2000)
-Use pulsed jets
-Use 3D shaping (hello modern planes wings!)

Of course..if you compare a 1,5 tons cessna with a 470 tons 747, yes it does produce far greater turbulence..

Ah and by the way, the Wake separation standard for A380 is the same than a 747 weighting 100 tons more! Yes...airbus did some of the above mentionned measures.

Come on, if you do not want wake effects on following car...ban wings and GE!!

[WhiteBlue]

Of course..if you compare a 1,5 tons cessna with a 470 tons 747, yes it does produce far greater turbulence..

Ah and by the way, the Wake separation standard for A380 is the same than a 747 weighting 100 tons more! Yes...airbus did some of the above mentionned measures.

I'm sorry to tell you that you got your facts wrong. A380 are classed "Super" while 747 are classed "Heavy".

http://en.wikipedia.org/wiki/Airbus_A38 ... separation

In August 2008, the ICAO issued revised approach separations of 4 nmi (7.4 km) for Super (another A380), 6 nmi (11 km) for Heavy, 7 nmi (13 km) for medium/small, and 8 nmi (15 km) for light.[170]

These compared with the 4 nmi (7.4 km), 5 nmi (9.3 km) and 6 nmi (11 km) spacing applicable to other "Heavy" aircraft.

In a table of nautical miles for heavy, medium and light aircraft it looks like this:

A380......6.........7..........8
747........4.........5..........6

The additional spacing for the A380 is 50%, 40% and 33%. On average the spacing behind a landing A380 has to be +40%. The additional weight of the A380 is 120 ton more than the max weight of a 747. This is 27% more. It shows again that even the most important billion dollar projects cannot deliver less turbulences when the aero force increases. In fact the turbulence increases more than the max take off weight increases.

[Ogami musashi]

The additional spacing for the A380 is 50%, 40% and 33%. On average the spacing behind a landing A380 has to be +40%. The additional weight of the A380 is 120 ton more than the max weight of a 747. This is 27% more. It shows again that even the most important billion dollar projects cannot deliver less turbulences when the aero force increases. In fact the turbulence increases more than the max take off weight increases.

That is only for take off and landing (with flaps on), cruise spacing is the same and another A380 has no restriction following another A380.


The first fact is because of increase in coefficient of lift when flaps are on, combination of wakes from flaps (which are larger than on other planes) and wings; Cruise spacing shows that even with the additional weight of A380 (thus additional lift) the wake strength is the same and finally the non restriction for another A380 shows that wake effects depends a lot on geometry.

Well ma..that's what i said the post before.

[WhiteBlue]

And you are wrong again. The latest reports suggest that wake turbulences of Supers have been noticed at 300 meters below their actual flight level. The authorities are in the process to review and restrict in flight clearances.

BTW I think that take of and landing wake is far more relevant to race cars than in flight wake. They happen in the ground effect zone as all the race cars work.

[Ogami musashi]

And you are wrong again. The latest reports suggest that wake turbulences of Supers have been noticed at 300 meters below their actual flight level. The authorities are in the process to review and restrict in flight clearances.

source.

BTW I think that take of and landing wake is far more relevant to race cars than in flight wake. They happen in the ground effect zone as all the race cars work.

No.. nothing to see; planes vortices go downward, Cars upward and by the way in contrary to plane cars do not increase their AOA (which increases the tendency to go downward).

That in addition that it is still not down to level of downforce.

The simple fact is that a plane would have infinite span, there would be zero vortices.

[WhiteBlue]

BTW I think that take of and landing wake is far more relevant to race cars than in flight wake. They happen in the ground effect zone as all the race cars work.

No.. nothing to see; planes vortices go downward, Cars upward and by the way in contrary to plane cars do not increase their AOA (which increases the tendency to go downward).

That in addition that it is still not down to level of downforce.

The simple fact is that a plane would have infinite span, there would be zero vortices.

I don't think we will ever agree on this. Race cars obviously do not fly in free air. This is why turbulences on the ground are much more relevant. You only have one direction for the wake to develop and this is up because under the car or plane you only have the track or run way. I don't see a big difference weather you have a lift or a downforce. The wake pattern surely will be different if the force is inverted. But as already shown the wake turbulences by aircraft ground traffic are proportional to the aerodynamic force. It is unreasonable to think that this isn't true for race cars only because the force is inverted.

I'm tired of this and I don't intend on taking this forward. I will obviously not change your opinion. Let us give it a rest.

[autogyro]

This might help WhiteBlue. A friend of mine had his Cessna 172 flipped upside down by the wake turbulance of a Jumbo at a range of two miles.
Mind you there will still be those saying the complete oposite.
Its this damn aero DF God that does it.

[Ogami musashi]

I don't think we will ever agree on this. Race cars obviously do not fly in free air. This is why turbulences on the ground are much more relevant. You only have one direction for the wake to develop and this is up because under the car or plane you only have the track or run way.

Err, vortex of cars goes to the sky; on a plane they go to the ground and the seriously mix up with the ground atmospheric turbulence;

i don't see how this can be seen identical. Ground effects in car and in Plane (which use the downward movement of air) are totally different for that very reason.

I don't see a big difference weather you have a lift or a downforce.

I see thaT...but that doesn't mean you're right.

But as already shown the wake turbulences by aircraft ground traffic are proportional to the aerodynamic force.

Okay i give up. You still haven't understood the simple concept of multiplication.

I'm tired of this and I don't intend on taking this forward. I will obviously not change your opinion. Let us give it a rest.

For once..i agree.

[strad]

W/B wrote

I don't intend on taking this forward

Thank God!!!!!!!

[autogyro]

W/B wrote

I don't intend on taking this forward

Thank God!!!!!!!

Ogami, he is asking for you.