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Old 11-26-2013, 07:42 PM   #41 (permalink)
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Originally Posted by Otto View Post
Well, page 158 (fig. 4.31) of Hucho's 4th ed. book says the optimum shape is 14% less drag than the base shape, does it not?

Perhaps I'm misreading pages 157 & 158. Upon reviewing them, what's your take?
I believe that in the bar graphs,you see that after the very small radii were introduced to the 'basic' profile,that VW essentially achieved (within spitting distance) the same drag reduction as with the 'ideal' nose.
This is the concept of detail optimization that Hucho has hammered away at for decades.And why he is so quick to encourage the aft-body streamlining.
The forebody is in the most favorable pressure gradient,with the flow held against the body as it accelerates along the increasing body section towards the minimum pressure line.
You can have a lot of sins up front and still maintain attachment.

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