Underbody Vortex Generators.. 1

[Chezee350]

Hi..

some of you might have seen the Vortex Generators that Mitsubishi included in the latest rendition of their Lancer Evo VIII MR.

image:

link:

http://www.mitsubishi-motors.com/corporate/about_us/technology/review/e/pdf/2004/16E_03.pdf

i was wondering what race teams are using to keep turbulent air flow that is uner the car, attached to smooth underbodies of race cars, especially for the rear diffuser, since the prolonged attachment of airflow to a rear diffuser would suck the car down better than if the air seperated sooner, what shapes or anything is used for this?

thanks!

 

[72miura]

I believe that some cars may do this to keep flow attached on the underside of ground efects tunnels.

Carroll Smith suggested the use of vortex generators to keep flow attached on the under side of high angle of attack wings and in ground effects tunnnels.

To me, in theory it makes sense that it would work.

 

[evelrod]

There was an article recently about this very subject as it related to Fords GT 40. It seems the old race cars suffered from terrible aerodynamics (oh shucks, I am shocked!) and the re incarnation of the car for street was equally awful in it's initial configuration. Most of the work centered on the rear diffusers and the front diaplane/spoiler...The sad part of all this? I don't remember which mag I read it in! Sorry...Google, I guess.

Rod

 

[ArizonaSpeed]

Vortex generators are more effective where there is laminar airflow and then there's a sudden airflow seperation. Although I suspect it would work before the point of airflow seperation if it's occuring in the diffuser area.

If it is occuring, one thing that will help is adding or adjusting a rear spoiler or a wing.... as it works together with the diffuser.

Here is some reading on the subject:

http://www.advantage-cfd.co.uk/Newsletter/Newsletter-Articles.html

See Volume 15 no. 2

Dave

 

[Kmelthratter]

I may not be correct, but dimples on golf balls are for traction (so that the spinning of the gold ball can change its direction) are they not?

 

[bvanhiel]

I may not be correct, but dimples on golf balls are for traction (so that the spinning of the gold ball can change its direction) are they not?

No, they're not for traction. Dimples delay flow separation. Do a google search and you'll find lots of discussion.

-b