Drag reduction modifications in wind tunnel: Audi A2 from Cd 0.288 to 0.204

[paulu]

This was just one presentation from the "The Aerodynamics Challenge Dissemination Event on 19 October 2011"

Some more presentation can be found here :
Coventry University - The Aerodynamics Challenge

[CigaR007]

I have often wondered if there is a "synergy" effect when combining different drag reduction mods. Would there be a perfect combination ?

[Cd]

Originally Posted by paulu

This was just one presentation from the "The Aerodynamics Challenge Dissemination Event on 19 October 2011"

Some more presentation can be found here :
Coventry University - The Aerodynamics Challenge

This is a gold mine of information !
Thanks so much for sharing .


Is any of this presentation available on YouTube or elsewhere as a video ?
I would have loved to hear what the speakers had to say .

[Piwoslaw]

Originally Posted by Vekke

A2 3l Had 0.25
145/80R14 tires
Lower ground clearance
smooth hubcaps
almost fully blocked front grille
smooth underside to some extent
plus lots of small modifications

Plus a lighter rear seat. Did it also have lightweight (magnesium) suspension elements? This, of course, doesn't effect aero.

[gone-ot]

...this presentation (aft body taper) looks interesting too: http://wwwm.coventry.ac.uk/researchn...ple%20body.pdf

...and, here's Jaguar info on wheel design: http://wwwm.coventry.ac.uk/researchn...l%20Design.pdf

[Vekke]

Lots of useful data which need lot of thinking to be able to use that when engineering/making parts. I liked those moving wheels, because I had one similar idea that was there also.

[sendler]

So is their 2 inch concave tail section showing me I should fit the skin 2 inches long to form a concave at the back of the Kammed off tail I am building for my Vetter style motorcycle?

[ecofreak]

Originally Posted by sendler

So is their 2 inch concave tail section showing me I should fit the skin 2 inches long to form a concave at the back of the Kammed off tail I am building for my Vetter style motorcycle?

I'm sure with a motorcycle, your Kamm will be much more pointed/tapered than a subcompact car. You could probably get away with six inches of cavity if it gave you much less added weight and if the Kammback was only a few square feet in area.

On a motorcycle, your Cd is basically just a raw factor of your frontal area. That's why a recumbent riding position is one of the most effective ways to bite a chunk off your fuel consumption. As long as your fairing is rigid in the wind, your mpg will kick butt. The rear back inches of the Audi fairing would end up being negligible on a motorcycle when compared to weight gain/frontal Cd.

Good luck with your motorcycle, sendler. We'll all love to see what you'll come up with!

[sendler]

Originally Posted by sendler

So is their 2 inch concave tail section showing me I should fit the skin 2 inches long to form a concave at the back of the Kammed off tail I am building for my Vetter style motorcycle?

As opposed to just squaring it off at half chord I should say.

[ecofreak]

Originally Posted by sendler

As opposed to just squaring it off at half chord I should say.

An extra two inches wouldn't hurt. You'd probably see improvement. Beyond two inches of whatever the study Audi used was not stable enough to hold it's shape in the wind.