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Old 03-29-2010, 06:11 PM   #24 (permalink)
aerohead
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Ernie's wing

I located my photo of Ernie's New Beetle.It's in orthogonal projection,so nothings really in true-length,but the angle of the car allowed a cursory noodling.
It appears that the centerline of the backlight hits 22-degrees about 1/2 a door handle length down the glass and I would suspect that the flow is very feeble,if not separating there.
Down at the bottom of the glass,the angle is on the order of 34-degrees with the horizon.
A protractor reveals that Ernies wing relaxes that angle to about 19-degrees,well within Mair's 22-degree limit.
If you place a French-curve over the car,with and without Ernie's wing,it looks like the wing 'doubles' the apparent length of the car's aft-body at centerline ,where the imaginary line would intersect the ground.
With respect to the streamlining template,at centerline,it would be the same as taking the Beetle with 30% of an aft-body,and extending it out
to about 80 %.
Of course the sides aren't done,but you can see how the wing could definitely help push Ernie into 50+ mpg territory.Sweet!
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