Thread: Discussion XC#10 in a series, Giant Icon?
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Old Jun 24, 2010, 11:42 PM
G Norsworthy is offline
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United States, CA, San Jose
Joined Sep 2008
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Further analysis

Getting faster at this now that I have a method.

A 15 mile race does not change the ranking. I think you would have to go to a really short race to take advantage of the extra height of the 14" chord, something like the 10K we used to run in central FL.

Now the interesting part. I took a set of airfoils thinned and decambered from the AG23 series used in #8. Put those on the same airplanes plus one that TrekBiker designed. They all beat their respective wing in the AG23 series group, but the only one that stands out is the 12" chord. Now you have both aspect ratio and wing loading, and those win out over altitude. XFLR5 gave this wing a flatter glide slope below 1200m and that is what does it. Either there is a peculiarity in the program or this is the truth. In any case it highlights the importance of planform and airfoil progression. Now I understand the difference between TLAR and running the analysis. There must be more to be gained, especially with camber change.

#8 V2 Airfoils 97.11
150 Span V2 97.37
170 Span V2 98.6
12" Chord V2 89.2
14" Chord V2 97.54
TrekBiker 12" 93.13
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Last edited by G Norsworthy; Jun 25, 2010 at 05:09 PM. Reason: error in polynomial coefficients
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