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Oleg,
Thank you for your comments. My apologies for missing the Span Loading
differentiation on the first go around.
That said, I still don't agree with the trends you've noted unless one is
dealing with the induced drag term (and wing) in isolation from everything else.
You can't ignore the weight scaling like that in a realistic scenario. It's
academic but unreasonable.
But this IS getting too detailed for more dialog here (I think).
I would really prefer to see analyses done on the whole planform rather
than relying on trends from individual engineering equations.
To that end, I'll find a web site and post the polar program I've developed
over the past 15 years or so. I don't see anything like that available as
freeware on the web anyway. It will have the articles used to derive the
formulation (RCSD series in 2000) as well as the source code, airfoil database
(derived from UIUC and some X-foil runs) and the compiled and installation
files.
It's in VB6 and can be modified by anyone that wants to use it. It has been
run (years ago) against the original Princeton work and other early DOS based
codes (developed by folks with more credibility). It reproduced those results
very well. It's independently derived and written by me but is reasonably
robust. I know the parasitic drag estimates are low and I'm trying to get flight
data to correct that.
It will take about a week to put this together. I'm changing our ISP this
week so hopefully next weekend I can set this up. I'll send a post to RCSE when
it's done.
If anyone tries it and has feedback, that would be appreciated. Hopefully
the Windows GUI will make it easier for folks to do this type of analysis if
their interests require it. And the source code and notes allow for corrections
in areas that are deficient.
In the meantime, thanks for the dialog. I understand your points but think
the view is rather constrained.
- Dave R
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