Anyone that is interested in aerodynamics and streamlined shapes might want
to visit this website: http://www.speed101.com/photos.htm . Scroll down
near the bottom of the page until you see these headings: "The Virtual
Edge" and "The ETA Edge". The Virtual Edge is a streamlined bike built by
Matt Weaver that's gone 78 mph on human power. The Virtual Edge is Matt's
new bike. You'll see a picture of the Virtual Edge which has done 78 mph on
human power and a diagram of the design for the ETA Edge. The pictures are
probably worth a thousand or so emails.
Then be sure to check out the link ( http://www.speed101.com/words.htm ) to
a discussion the principles behind the shape and what he was trying to
accomplish.
* Scroll down to "The "Virtual Edge" - Technical Notes". (The Virtual Edge
was the predecessor to the ETA Edge, and used the same principles employed
in the ETA Edge.)
* Now, scroll down to these headings: "Extensively Natural Laminar Body"
and "Body Design".
He's using a shape that's sorta like an elongated egg, with the small end
in the front. Or, maybe a backwards teardrop. This design helps maintain
the laminar flow of air in the boundary layer for as long as possible along
the length of the vehicle. According to him, when the laminar flow is
disrupted the resulting turbulence increases drag 300% on the surface of
the vehicle at all points downstream of the interruption. That's probably
what caught my attention. So the long, gentle curves in the front maintain
the laminar flow, and the short steep curves in back reduce the amount of
body caught up in the turbulence.
BTW, does anyone know where to get a good deal on about 10 Red-Top 12-volt
Optimas?
Henry Deaton
Sunny San Francisco
(Yes, I'm still working on my bike)
>Can I assume that a teardrop is still a good aerodynamic shape?
>What is the 'best' aerodynamic shape? Does the best shape change
>as frontal area changes? (I realize that ground effects will
>require a change to the perfect free air shape.)
>
>Are we back to a belly tank with a stabilizing fin?
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/// what is needed. It isn't that difficult, folks.
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