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Old 01-14-2014, 06:39 PM   #23 (permalink)
aerohead
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sharp angle vs 'Template'

Quote:
Originally Posted by Xist View Post
Aerohead, somehow I had not seen your response. I will wait for my girlfriend to come over, ask her how to determine the angles, and like I do far too often, groan in exasperation, and then she will laugh at me.

Beluga and Aerohead, I apologize for not using words like a big boy, but as usual, like right now, I really needed to be doing something else, so I hoped that you guys could figure out what I intended. Beluga, instead of building a giant boat tail, I bought a Civic HX, and went from twenty-seven to forty-seven MPG.

Aerohead, how come the sharp angles that do not follow the template are inherently more aerodynamic? It looks like the earlier and the sharper the taper, the better.

Would completely removing a truck bed be more aerodynamic than building an aerocap?
Xist,I'm going to try and answer your question with some additional visual drag tables which I'm currently working on.
You'll find that things are extremely conditional/contextual.
The sharp angled test models were a way for Buchheim and his team to start with extremely fundamental shapes,collect data,and then expand out from there.Buchheim ended up with the 'Template',producing bodies as low as Cd 0.14.Kamm did the same thing,starting in the mid-1930s.Kamm's 'Template' produced Cd 0.12.Same as Walter Lay's 'Template' of 1933.THe original 'Template' dates to 1922,with Paul Jaray's airship-inspired 'pumpkin seed' half-body car of Cd 0.13.
I've completed some photo-copy work on the new tables and will work on them through the week.Hope to post next Saturday.
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With respect to the pickup truck,I removed the bed from my Dodge pickup and lost 2-mpg,as well as causing an overheat condition.
Constructing a custom,streamlined bed/cover would be better than just an aeroshell.I have one of those as a work-in-progress which I hope to complete before the world ends.
From some of the other tables you can already see that the sharp angles don't deliver the 'lowest' drag,they only beat the 'Template' when all the other parameters which allow the 'Template' to function are abandoned.
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