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Old 08-31-2015, 05:16 PM   #652 (permalink)
aerohead
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included angle

Quote:
Originally Posted by freebeard View Post
I like that he uses the VW Beetle as a benchmark. It's relevant to my interest.

1.75/2.5=0.7. Assuming a 12' length, increasing the Beetle's fineness ratio to 2.5 would require a 5.14ft boattail. What is the included angle at the tip of the optimal body? I used 45°, as close enough to 2*22° in my experiment with redwood lath, and got a boattail length of 3ft.
For ground reflection in elevation Mair suggests 44-degrees,Buchheim 46-degrees.
For plan-view,technically it would be the same.
I'm favoring the tail contour of the 3.92:1 airfoil section for plan-view.
I can't defend it scientifically.It allows a wider rear wheel track.
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