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Old 07-30-2013, 05:19 PM   #26 (permalink)
aerohead
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form factor

Quote:
Originally Posted by sendler View Post
Something like foil Sim would be more than good enough to give us an idea if we could manipulate the shapes to suit our questions in general.



I already commented on the fuselage chart. It is way too long in form factor. By the time you take away 40% of the length, the sides are already straight. It is no longer a Kamm. It is a round nosed bullet.





That is the correct shape but doesn't make sense. Where are they measuring "l"?
The chart and its values are only for a fuselage of the fineness ratio shown.I selected it because I didn't do the research.It was tested at Germany's NASA,the DVL,where Kamm spent some of his time.
The 2.5:1 fineness ratio fuselage has the lowest drag.Cd 0.04
In ground effect its drag rises to Cd 0.08
When 'gross' wheels are added,it goes to Cd 0.12.
If you truncate it at 60% you should see the same 28% drag increase,or Cd 0.15.(drag of the body is figured separately with drag of wheels held constant).
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