Some free papers (pdf) on race car aerodynamic

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747heavy
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Some free papers (pdf) on race car aerodynamic

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Last edited by 747heavy on Tue Aug 31, 2010 10:02 pm, edited 5 times in total.
"Make the suspension adjustable and they will adjust it wrong ......
look what they can do to a carburetor in just a few moments of stupidity with a screwdriver."
- Colin Chapman

“Simplicity is the ultimate sophistication.” - Leonardo da Vinci

DaveKillens
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Re: some free papers (pdf) on race car aerodynamic

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Thank you very much 747heavy, it all adds to my knowledge base.
Racing should be decided on the track, not the court room.

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mep
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Re: some free papers (pdf) on race car aerodynamic

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Very nice posts 747heavy, =D>


One thing is surprising for me in particular.
In the first paper is written that most race cars have their Centre of pressure (CP) behind Centre of gravity (CG) to have better stability (page 19).

Ok they are talking about stability.
Anyway I got the idea that a CP in front of CG is better for cornering because the front tires need to transmit higher forces to corner the car.
So placing the CP in front of CG should raise maximum cornering speeds.
What do you think about it?

Just_a_fan
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Re: some free papers (pdf) on race car aerodynamic

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Excellent. Now that I've finished my dissertation I can enjoy reading something not related to my Masters course for the first time in 2 years!
Turbo says "Dumpster sounds so much more classy. It's the diamond of the cesspools." oh, and "The Dutch fans are drunk. Maybe"

ChrisTipper
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Re: some free papers (pdf) on race car aerodynamic

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This is great help, thanks and this could help with my degree
Engineering student,but still learning alot about Formula One cars and I can Admit that

G37Sam
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Re: Some free papers (pdf) on race car aerodynamic

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Downloaded, thanks for sharing :)

Mystery Steve
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Re: some free papers (pdf) on race car aerodynamic

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mep wrote: Anyway I got the idea that a CP in front of CG is better for cornering because the front tires need to transmit higher forces to corner the car.
So placing the CP in front of CG should raise maximum cornering speeds.
What do you think about it?
I see the idea you're going for, but that would make things very unstable and hard to control at high speed. Next time you're playing darts, throw one backwards and imagine it's a Formula 1 car. While I do realize that is an extreme example of a forward center of pressure, the basic concept is the same.
Just_a_fan wrote:Excellent. Now that I've finished my dissertation I can enjoy reading something not related to my Masters course for the first time in 2 years!
It feels good, doesn't it... :)

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747heavy
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Re: Some free papers (pdf) on race car aerodynamic

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"Make the suspension adjustable and they will adjust it wrong ......
look what they can do to a carburetor in just a few moments of stupidity with a screwdriver."
- Colin Chapman

“Simplicity is the ultimate sophistication.” - Leonardo da Vinci

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747heavy
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Re: Some free papers (pdf) on race car aerodynamic

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aero vs. mecanical grip - roundup 2010 - nice

http://www.f1-forecast.com/pdf/F1%20Sea ... on%203.pdf
"Make the suspension adjustable and they will adjust it wrong ......
look what they can do to a carburetor in just a few moments of stupidity with a screwdriver."
- Colin Chapman

“Simplicity is the ultimate sophistication.” - Leonardo da Vinci

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747heavy
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Re: Some free papers (pdf) on race car aerodynamic

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sorry in French only, a documentation about the history of aerodynamic development in F1 - some nice photos and graphics

http://www.f1-forecast.com/pdf/F1-Forec ... le%201.pdf
"Make the suspension adjustable and they will adjust it wrong ......
look what they can do to a carburetor in just a few moments of stupidity with a screwdriver."
- Colin Chapman

“Simplicity is the ultimate sophistication.” - Leonardo da Vinci

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747heavy
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Re: some free papers (pdf) on race car aerodynamic

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mep wrote:Very nice posts 747heavy, =D>


One thing is surprising for me in particular.
In the first paper is written that most race cars have their Centre of pressure (CP) behind Centre of gravity (CG) to have better stability (page 19).

Ok they are talking about stability.
Anyway I got the idea that a CP in front of CG is better for cornering because the front tires need to transmit higher forces to corner the car.
So placing the CP in front of CG should raise maximum cornering speeds.
What do you think about it?

Hi mep,

To be honest, I don´t 100% know what he means in this article.
For me it looks like he is talking about CoP in sideview, then what he says and explains makes sense.
And this goes along the lines of what Mystery Steve says.
It´s the "weather vane" (Wetterhahn) effect, which helps with longitunal stability under yaw conditions. Imagine the car goes sideways at high speeds, if you have your CoP behind the CoG, the resulting force will try to straighten the car and makes it a bit understeer. This is a very safe and stable condition, because the effect reduces it´s self when the car straightens out. If you have a CoP before the CoG, the resulting force will increase yaw/turn in the car more, until it travels backwards. That´s a very unstable and difficult to control condition.
You see this in F1 with the extended engine covers. With this concept, you can setup the car a bit more oversteering for the low speed corners, and it will get more neutral/understeering in the medium and fast corners.

Here another explaination from Vasslon:
>>>>
Toyota used four identical scale models to develop aero parts for the car in its on-site tunnel, and one of the more unusual components that were introduced was the ‘humpback’ engine cover. ‘They are very simple,’ explains Vasselon, ‘it doesn’t bring a lot, it’s just something which improves stability under lateral wind, it has no effect in pure straight line aero. There was almost no aero development on this part, it was just a case of creating surfaces rearward. We went to it after checking there was no unexpected detriment. You see similar concepts on Le Mans cars – you move your centre of pressure rearward, so if you have lateral wind you create a stable car that can brake and steer.’
<<<<

I don´t think, the guy in the report referes to the vertical CoP (downforce distribution) of the car.
If you have your CoP for vertical pressure (downforce) at your CoG, the car will have the same balance (US/OS) throught the speed range. It´s normally a good starting point.
From here you can use your front wing or rear wing adjustments to move the CoP in relation to the CoG forward or backward, to achieve the desired characteristic.
If you have your CoG wrong (not optimal) you can try to compensate with a different CoP, but this means the characteristic of the car (US/OS) will change with speed.

That´s my take on it, but I could be wrong, and there a probably other members on this forum, which know more about it, and can explain it better, then I can.
"Make the suspension adjustable and they will adjust it wrong ......
look what they can do to a carburetor in just a few moments of stupidity with a screwdriver."
- Colin Chapman

“Simplicity is the ultimate sophistication.” - Leonardo da Vinci

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747heavy
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Re: Some free papers (pdf) on race car aerodynamic

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some info about CFD simulation in F1

http://ditwww.epfl.ch/SIC/SA/publicatio ... age11.html
"Make the suspension adjustable and they will adjust it wrong ......
look what they can do to a carburetor in just a few moments of stupidity with a screwdriver."
- Colin Chapman

“Simplicity is the ultimate sophistication.” - Leonardo da Vinci

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747heavy
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Re: Some free papers (pdf) on race car aerodynamic

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Last edited by 747heavy on Tue Aug 31, 2010 10:04 pm, edited 1 time in total.
"Make the suspension adjustable and they will adjust it wrong ......
look what they can do to a carburetor in just a few moments of stupidity with a screwdriver."
- Colin Chapman

“Simplicity is the ultimate sophistication.” - Leonardo da Vinci

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fausto cedros
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Re: Some free papers (pdf) on race car aerodynamic

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Just saw this, i guess that i'll post my thesis when i have time (but it's in italian!)
I didn't have time to read the article, but i think the following:
having the cop ahead of the cog will make the car oversteering;this is an unstable condition because at a given steering angle, an increase of speed will increase the centrifugal acceleration (v^2/R) and turn diminish the turning radius, this favouring a further increase of the centrifugal force, the lateral loads and pushing the car to the limit in a nonlinear fashion.
Having the cop behind the cog will make the car understeer. in this case at a given steering angle the increase of speed will enlarge the turning radius, this way counteracting the increase in centrifugal force due to the speed increase and preventing the car to unwillingly, nonlinearly reach the limit.

(Or so it's supposed to be :D )
"Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere" Anthony Bruce Colin Chapman

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747heavy
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Re: Some free papers (pdf) on race car aerodynamic

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"Make the suspension adjustable and they will adjust it wrong ......
look what they can do to a carburetor in just a few moments of stupidity with a screwdriver."
- Colin Chapman

“Simplicity is the ultimate sophistication.” - Leonardo da Vinci