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Old 01-28-2010, 06:05 PM   #27 (permalink)
aerohead
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teardrops

Quote:
Originally Posted by ChazInMT View Post
MJ, I am using exactly what Aerohed described. I have analyzed the shape you posted here and have the results below. I hope it makes sense.


In this image I have placed your teardrop ideal and the ideal that Aerohed presented earlier. Your shape is the bright green one in this image. My shape is red. I have been extremely careful not to mess with any of the proportions of these shapes at anytime. Also, I have made a circle in my drawing program and have marked a point which is 25 past center and then I trace this shape to get my template, I did not simply trace Aeroheds foil shape.



In this image I have overlaid my shape (bright green) with the foil cross sections which I got from somewhere. You can see that my shape closely approximates the shape # 5 on this chart, your shape (red) is pretty close to #7.

I have noticed that the nose shapes on Aeroheds foil, your template, your ideal foil, and these foils on the chart are all quite different. This I suppose could be the subject of a new discussion.
The lower teardrop image within streamlines is from Baron R. von Fachsenfeld.This drop has a L/D ratio of about 2.72:1 which is a little longer than what is necessary.
Your green line drop would have the lower drag.
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