Aerodynamic Streamlining Template: Part-C

[kach22i]

Originally Posted by SvdM

a recent competition on the GrabCAD site.

I registered on that site a few weeks ago so that I could contact somebody. Looked interesting, still have not posted.

Nice project, could you post a direct link to the contest if it is still up? It's the only way I can determine how successful you were, looks great without knowing anything about it though.

[SvdM]

The contest is in the judging phase, but I'm not sure when they announce.
Supercar Body Challenge - GrabCAD

[aerohead]

Originally Posted by SvdM

The contest is in the judging phase, but I'm not sure when they announce.
Supercar Body Challenge - GrabCAD

If they intend to drive these 'supercars' as one might the Bugatti Veyron then I suppose that induced drag will be a mandatory component of the design,and preclude any significant body plan taper necessary for meaningful drag reduction.

[kach22i]

Originally Posted by aerohead

If they intend to drive these 'supercars' as one might the Bugatti Veyron then I suppose that induced drag will be a mandatory component of the design,and preclude any significant body plan taper necessary for meaningful drag reduction.

Using the Bugatti Veyron drag (and down-force) as an example.............
the Bugatti Page: Bugatti Veyron driving experience

But 230 mph is about as fast as the Veyron will go until you put the car into top-speed mode. This involves coming to a stop and, while the car is idling, turning a key in a lock on the floor to the left of the driver's seat. When you do that, the car sinks down even lower on its suspension, until ground clearance has been reduced to a mere 2.6 inches in front and 2.8 in the rear. This setup also causes the front underbody flaps to close and the rear spoiler and wing to retract, although the wing remains tilted out of the body at a slight two-degree angle. These changes reduce the car's drag coefficient from 0.41 to 0.36, and they reduce the peak downforce from 770 to 120 pounds..

Some Cd listings posted.
Automobile drag coefficient - Wikipedia, the free encyclopedia

..............the same Cd as...........

0.36 Honda Civic 2001–2005

Just trying to put it all in perspective.

[aerohead]

Originally Posted by kach22i

Using the Bugatti Veyron drag (and down-force) as an example.............
the Bugatti Page: Bugatti Veyron driving experience


Some Cd listings posted.
Automobile drag coefficient - Wikipedia, the free encyclopedia

..............the same Cd as...........


Just trying to put it all in perspective.

When you consider that the Gale Banks GMC S-15 Syclone pickup truck was Cd 0.315,the 'supercars' don't seem so sexy.Although if I were to find myself at 268 mph,the induced drag would be lookin' pretty good.

[aerohead]

The 'Template' is based on a 2.5:1 streamline body of revolution depicted in Hucho's 2nd-Edition.You can see this image in the attached thumbnails,3rd from the left below the latest 'Template Part-C' image.
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I found a larger image of this same specification teardrop for those members attempting a mathematical or CAD representation of the form.
I can't post the image today,as the computers here are being converted to Windows-7,from XP.
I'll give the source for those members who'd like to double-check:
Fig.10.26,p.315,Chapter 10,"Forces on Immersed Bodies",Fluid Mechanics with Engineering Applications,Robert L.Daugherty,Joseph B. Franzini,Seventh Edition,McGraw-Hill Book Co.,1977,ISBN 0-07-015427-0
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I've photo-enlarged the image up to 11"X17" scale.It's a little grainy do to it's small original dimensions,but perhaps those interested can clean it back up.
I'll try for next weekend.
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Here's a try

[ksa8907]

could someone overlay this for me, im terrible at photo editing, no idea where to start.

[freebeard]

My copy of the template has a note that says equal height for the roof and equal wheelbase for the ground clearance. So I broke it up into two.

The ground planes are 1-2° out so I averaged that. And converted to jpg for transparent layers.

[ChazInMT]

Here, I used my own version of the template cause I dunno how to make the other one transparent.

Here's a bigger snap of the same thing to analyze better.

Bigger version of Intrepid with Template

[freebeard]

ChazInMT & ksa8907 -- .GIF is an indexed colorspace; if you convert to RGB you can do transparent layers.

In my 10-year-old copy of PhotoShop Elements it's under Image/Mode.