Random Wind Tunnel and Smoke Pictures Thread

[aerohead]

Originally Posted by freebeard

Rake it or lower the stagnation point.

I still think the towel-rack wing could be turned upside down and make a dandy diffuser, the modern way to make downforce.

And ditch the pop-up headights for a strip of LEDs just before the front edge of the hood.

*The Daytona rake was analyzed and what they settled on was optimized for their target performance.Passenger cars had to be like the race car for homologation purposes,or otherwise they would have never been allowed to race it. (Tail wagging the dog).
*The air under the car might not be suitable for a wing.And it would have to be much larger because of it in order to create the same amount of force.That's why it was placed so high in the airstream.To minimize drag.
NOTE: Chrysler DID want to place the spoiler directly over the rear axle,but they considered that a non-starter.

[kach22i]

http://ecomodder.com/forum/showthrea...k-26965-7.html

[Cd]

Thanks for that last post of the Beetle. I never expected attached flow at the windshield / roof junction - especially this clean.
I'm constantly amazed at what air does, vs. what I THINK it will do !

[freebeard]

You can trace back from that late windshield to the pre-60 version where the contour is the same but the glass shrinks to give a more generous rounded edge. It doesn't really help, and it's like looking out the mouth of a cave. Things really didn't change until the 1303 Superbeetle. That windshield is maybe worth 4mph top speed at Bonneville.

I don't know if I trust that picture though. If there're those inward rolling vortexes off the drip rail, why don't the smoke streams roll into cones?

[Cd]

Originally Posted by freebeard

I don't know if I trust that picture though. If there're those inward rolling vortexes off the drip rail, why don't the smoke streams roll into cones?

I would think because we are seeing just one stream of smoke, and it is centrally located, right at the centerline of the car.

( You were referring to the drip rails above the doors, yes ? )

[aerohead]

Originally Posted by freebeard

You can trace back from that late windshield to the pre-60 version where the contour is the same but the glass shrinks to give a more generous rounded edge. It doesn't really help, and it's like looking out the mouth of a cave. Things really didn't change until the 1303 Superbeetle. That windshield is maybe worth 4mph top speed at Bonneville.

I don't know if I trust that picture though. If there're those inward rolling vortexes off the drip rail, why don't the smoke streams roll into cones?

So far,it seems like most presenters will show the most flattering view of their product.It must be poor etiquette to reveal the gruesome details.
Here's what Cd is talkin' about

[CFECO]

At what speed was the beetle tested at? That could have been 20 mph to make it look aero.

[Cd]

Originally Posted by CFECO

At what speed was the beetle tested at? That could have been 20 mph to make it look aero.

You mean like this thing :


Here is the video of the test, and the stream is a mess. Why did they choose to have the smoke all messy like that ? You can't make out a thing.

[gone-ot]

Key wording: "...generate DOWN force..."

[kach22i]

Gallery: Smoke streams are used to help designers and engineers fine tune the - The Challenge of Standardizing Aerodynamic Testing - Article - TruckingInfo.com


Wind Tunnel