concept cars aerodynamic

[fabrio]

I have seen more images about citroen C-Sportloungue and the Lotus "circuit car", and I have noticed the way in which the planners they have decided to isolate the front wheels aerodynamically.
some image:


By fabrio at 2007-07-22


By fabrio at 2007-07-22


By fabrio at 2007-07-22

about the lotus, from http://www.gglotus.org/ggrace/circuitcar/circuitcar.htm
You can read:
"#

Aerodynamics
# Flat bottom with front aero splitter and rear diffuser
# Aerodynamically designed body shape with minimal drag and frontal area
# Single plane rear wing, high downforce, carbon composite, dual element rear wing (optional)"

and about the citroen from:
http://car.kak.net/modules.php?op=mo...ticle&sid=4660

You can read this one:

"Optimised aerodynamic design

Special attention has been paid to the aerodynamic, flowing lines - strong Citroën values. The drag coefficient is 0.26 and rear lift 0.02. In addition to styling and volume that enhance air penetration, various technological features contribute to that result:

- air ducts on both sides of the front bumper. They produce an air flow through the front wheel arches, creating a virtual fairing.
- an electro-mechanical system at the rear of the roof. It consists of micro electro-mechanical systems (MEMs), which create a virtual airfoil by propelling jets of air and substantially improve the vehicle's drag and stability at high speeds.
- a reverse mobile airfoil, under the structure at the rear of the vehicle. This cylinder-activated reverse airfoil improves lift and enhances vehicle stability at high speeds. It has three positions:
- a "neutral" position, integrated with the rear styling, when the vehicle is stationary or in the city,
- a position adopted at a cruising speed of above 90 kph that optimises the drag coefficient and lift,
- a position activated during emergency braking to increase negative lift by adding support and stabilising the vehicle.
- the smooth subframe improves both drag and positive lift by optimising air flow under the vehicle.

This capacity to penetrate the air enhances the C SportLounge's efficient, dynamic handling, performance and environmental-friendliness."

Now, second you, this system in order to guide the air around the wheels is better or worse to the classics flow shunters?

for examples this?



It is possible, to install this particular system of air guide?

[lunarhighway]

wheel aerodynamics is a complex matter, and i'm not sure i fully understand it, but i'm sure there are ways to improve the airflow trough the wells.

the citroën seems to have two separate ducts. i think the lower ones are for break cooling and the upper ones seem to vent air into the upper wheelwell.

the second car seems to have one intake, but it might split internally to do the same.

i read somewhere that a lot of wheel drag is assosiated with the fact that the airflow follows the direction of the wheel. at the back of the wheel it's carried upwards into the wheelwell and than forward at the top of the wheel and than down again there it meets the oncoming air at the botton of the bumper. wich is partly why fairings (like you made) should work.

letting air into the wheelwell at the top might change the pressure and provide a better aerodynamic situation.

anyway that's what i've pieced together from things i found on the web, i'm not sure if what i say is right.

i think citroën's are a good source of inspiration (maybe production cars even more then concept cars) , because they have a long history of innovative cars and their FE is very good. the classic citroën DS for example has a completely flat underside and variable ground clearance. try to find that on a production car today!

[fabrio]

I suppose that, you refer at this image:



about my job http://www.gassavers.org/showthread.php?t=4385, I have noticed an increase of turbolent flow noise, you think thats are necessary an modification?

please, read my other topic:
http://www.gassavers.org/showthread.php?t=4429

also this:
http://www.gassavers.org/showthread.php?t=4431

I would appreciate your comment.

thanks

ciao

fabrio

[basjoos]

Increased wind noise is an indication of increased turbulence. As you decrease turbulance and drag, the car should produce less wind noise and become quieter.

[fabrio]

YES!!!!

but the nois is increased!

[Bill in Houston]

My car has a huge space around the rear wheels within the fender well. It is not needed for suspension travel, and is not occupied by struts or springs or anything like that.

Would it
a)possibly
b)probably
c)probably not
be helpful to make some fender liners to reduce the amount of space? They would basically be the shape of the wheel arch.

[fabrio]

Originally Posted by Bill in Houston

......

Would it

what means?

and this ?

Originally Posted by Bill in Houston

a)possibly
b)probably
c)probably not
be helpful to make some fender liners to reduce the amount of space? They would basically be the shape of the wheel arch.

excuse, but I do not understand

[Bill in Houston]

I was asking a separate question from yours, but related to wheel well turbulence.

[GasSavers_rookie]

Aero Mod Infohttp://www.hotrod.com/techarticles/b...ips/index.html

[fabrio]

Originally Posted by Bill in Houston

I was asking a separate question from yours, but related to wheel well turbulence.

ah... you can show to me a photo of wheel well ?