Aerodynamic Efficiency of F1 Cars

Here are our CFD links and discussions about aerodynamics, suspension, driver safety and tyres. Please stick to F1 on this forum.
Tommy Cookers
616
Joined: 17 Feb 2012, 16:55

Aerodynamic Efficiency of F1 Cars

Post

An F1 car could drive upside down along the top of the tunnel in the Monaco GP, as long as it maintained a certain speed. If the tunnel was sloping down at a suitable angle, this speed could be maintained even if coasting in neutral.
The angle of slope required would show the efficiency of the aerodynamics.

In this ground effect situation any aeroplane made in the last 70 years could glide (at its best speed) through the tunnel at a 1 degree slope.

What angle of slope would the F1 car need ? (sincere question)

Would this sort of test help in the Greening of F1 ?

Lycoming
106
Joined: 25 Aug 2011, 22:58

Re: Aerodynamic Efficiency of F1 Cars

Post

you realize nobobdy has actually driven an F1 car upside down in a tunnel before (though it is theoretically possible) and there are much better ways of demonstrating lift to drag ratio right?

bhall
244
Joined: 28 Feb 2006, 21:26

Re: Aerodynamic Efficiency of F1 Cars

Post

I'm sure someone will chime in with the appropriate numbers, but I've always heard/read the line that even just lifting off the throttle in an F1 car slows it down as if one was braking heavily in a road car and taken that as anecdotal evidence that drag on an F1 car is pretty damn high.

User avatar
WhiteBlue
92
Joined: 14 Apr 2008, 20:58
Location: WhiteBlue Country
Contact:

Re: Aerodynamic Efficiency of F1 Cars

Post

According to Charlie Whiting F1 cars exceed 2.5 tons of downforce. The aerodynamic braking effect is approximately 1g which compares to 640 kg. So you would never be able to glide the thing. Considering that the car only weights 640 kg with driver you cannot reach a glide angle even with 100% negative incline.

Regarding greener designs the federation wanted the cars to go to 1.25 tons of downforce if possible with equal performance but the technical working group which was set set up to propose a low drag chassis with tunnels was over ruled by the FOTA internal voting. So we will probably see the stepped floor design and similar wings for some more years. Personally I would like to see F1 migrate to a lower drag, higher efficiency configuration. It would tie in nicely with fuel saving direct injection turbo engines.
Formula One's fundamental ethos is about success coming to those with the most ingenious engineering and best .............................. organization, not to those with the biggest budget. (Dave Richards)

Just_a_fan
591
Joined: 31 Jan 2010, 20:37

Re: Aerodynamic Efficiency of F1 Cars

Post

A decent F1 car will have a L/D of 3:1 or better. I understand that they generally generate the equivalent to their weight at 100mph (so 640kg d/f at 100mph). So at that speed one would expect a drag of about 200-220kg.

The "braking at equivalent of a road car when lifting off the throttle" issue is, I believe, at top speed i.e. 180mph+.

The reason the cars are so draggy is because they are open wheelers with big rear wings that act as parachutes (the rear wing has a fairly poor L/D compared to the car as a whole) when they come off the power.
If you are more fortunate than others, build a larger table not a taller fence.

Tommy Cookers
616
Joined: 17 Feb 2012, 16:55

Re: Aerodynamic Efficiency of F1 Cars

Post

Many thanks

User avatar
P.S.
5
Joined: 23 Oct 2011, 17:09
Location: Germany

Re: Aerodynamic Efficiency of F1 Cars

Post

Just_a_fan wrote:The reason the cars are so draggy is because they are open wheelers with big rear wings that act as parachutes (the rear wing has a fairly poor L/D compared to the car as a whole) when they come off the power.
I like to add, that also closed wheeler like lmp1 don´t exceed an L/D of 5. Even an Airliner has about 12-15. Modern gliders are between 40 and 70 depending to class.

So, open wheeler or not, cars are in a different league than aeroplanes.
But L/D ratio is a key factor in saving fuel, while going still fast around corners. So rules need to be changend (more freedom) when fuel efficiency is desired.

Lycoming
106
Joined: 25 Aug 2011, 22:58

Re: Aerodynamic Efficiency of F1 Cars

Post

Cars are forced to use low aspect ratio wings because span is very limited, but a high lift coefficient is required. Although you can try and mitigate the effects by doing fancy things with the endplates, the fact is these wings generate a lot of induced drag. LMP cars do have much higher aspect ratios than F1 cars, and also generate more downforce from the undertray.

Also, a large part of the reason F1 cars are so draggy is because of the open wheels. There's a lot of turbulence around them, and they also represent a large percentage of the frontal area of the car.

bhall
244
Joined: 28 Feb 2006, 21:26

Re: Aerodynamic Efficiency of F1 Cars

Post

If dirty air is so bad for overtaking, how was Vettel able to stay right on Alguersuari's gearbox through those corners?
JohnsonsEvilTwin wrote:[youtube]http://www.youtube.com/watch?v=69qj1MeSlSE[/youtube]

User avatar
Kiril Varbanov
147
Joined: 05 Feb 2012, 15:00
Location: Bulgaria, Sofia
Contact:

Re: Aerodynamic Efficiency of F1 Cars

Post

bhallg2k wrote:If dirty air is so bad for overtaking, how was Vettel able to stay right on Alguersuari's gearbox through those corners?
JohnsonsEvilTwin wrote:[youtube]http://www.youtube.com/watch?v=69qj1MeSlSE[/youtube]
He was slip-streaming.

myurr
9
Joined: 20 Mar 2008, 21:58

Re: Aerodynamic Efficiency of F1 Cars

Post

bhallg2k wrote:If dirty air is so bad for overtaking, how was Vettel able to stay right on Alguersuari's gearbox through those corners?
Because he was doing something that we've seen Hamilton do a lot when trying to overtake - when following another car you take a slightly tighter line through the corner which positions your car into clean air restoring downforce. In the slower stuff you're more reliant on mechanical grip anyway.

Vettel wouldn't have been able to sit on Alguersuari's gear box through turn 8 in Turkey for example, as you can't really hold a tighter line through there and it's a fast aerodynamically limited corner.

MadMatt
125
Joined: 08 Jan 2011, 16:04
Contact:

Re: Aerodynamic Efficiency of F1 Cars

Post

Also the RB is way more efficient than the TR so that is giving Vettel an advantage too I think.

User avatar
strad
117
Joined: 02 Jan 2010, 01:57

Re: Aerodynamic Efficiency of F1 Cars

Post

Wouldn't Aerodynamic Efficiency imply something that slips thru the air? An F1 car with drag the equivalent of at least 1G is not very efficient. I think efficiency would imply little drag. Wouldn't it? A bullet has fair aerodynamic efficiency not an F1 car.
To achieve anything, you must be prepared to dabble on the boundary of disaster.”
Sir Stirling Moss

User avatar
Steven
Owner
Joined: 19 Aug 2002, 18:32
Location: Belgium
Contact:

Re: Aerodynamic Efficiency of F1 Cars

Post

Pat Symonds, 2004 wrote:Typically, adding downforce to the car must be balanced against the consideration of increased drag, but at Monaco - where overtaking is almost impossible - we are prepared to accept lower levels of efficiency. Where for an F1 car, a typical lift/drag ratio is in excess of 3 (essentially, to accept a 1 percent penalty in drag, you must find 3 percent or more downforce), for Monaco it is possible to drop below this magic ratio.

User avatar
strad
117
Joined: 02 Jan 2010, 01:57

Re: Aerodynamic Efficiency of F1 Cars

Post

I guess it depends on what you call efficiency...to me a lot of drag isn't very efficient
To achieve anything, you must be prepared to dabble on the boundary of disaster.”
Sir Stirling Moss