NACA 4 & 5 digit airfoils still used?
Brian R. Jones
general aviation aircraft, actually used NACA 4 and 5 digit series
airfoils in their wing design. My question is this: are they still
being used on modern aircraft (designs produced in the last 20 years
or so) and what aircraft employ them?
As an aerospace engineering student, I have studied them enough that
I would hope so. I do realize that since they are fairly simple,
they lend themselves to analysis and potential flow problems very
well, but it would be nice if there was a useful industry-related
side to their study as well. Many thanks!
-Brian
Jay Hardin
shown up in the last 20 years, other than homebuilts.
As far as what some of the current fleet uses, I know that the Cessna
152 and 172 use NACA 2412 airfoils, the Citabria has a 4412, and I
believe (not sure) that the Beech Bonanzas use 6-series airfoils.
With the availability of very good airfoil design programs these days,
almost no one uses the outdated NACA airfoils. Most of the new
homebuilt aircraft use airfoils custom-designed to meet the
requirements of the particular aircraft.
Jay
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Jay D. Hardin
Lockheed Martin
NASA Langley Research Center
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Dave J. Schwartz
Cessna Citations. The Cessna 210 uses a 6 series laminar flow section.
The Piper Cherokee also uses a 6 series, the 64(2)415 I believe;
however, it doesn't use it for laminar flow but rather because the
maximum thickness point of the airfoil is at a convenient place to run
the main spar through the cabin. The wing is riveted mostly with round
head rivets; so, extensive laminar flow is unlikely.
The Piper Commanche and the Mooney also use 6 series airfoils with
smooth flush riveted skins at least as far back as the max thickness
and thus may be able to achieve significant laminar flow if the wings
are clean.
The Cessna Cardinal also started out with a 6 series airfoil, probably
the same as the 210. I believe later Cardinals returned to the 2412.
The American/Grumman/Gulfstream singles are an odd case. The original
Yankee started out with an A modified (non-cusped) 6 series airfoil;
however, the rest of the A/C design really didn't allow it to operate
in the low drag region, and the price of poorer low speed handling was
not acceptable to the general aviation market. So the airfoil was
changed to a more conventional shape by the TLAR (that looks about
right) process. The lower forward portion of the airfoil was filled
out until a shape reminiscent of a 4 digit airfoil was created. This
was demonstrated to me by stacking a Yankee rib on top of the later
Trainer rib.
The Piper Tomahawk is the only GA craft I know of to try an use one of
the new GA airfoils. It uses the GAW-1.
For what it's worth, my Stephen's Akro also uses a 23012. Later
varients use 0012's or 0015's; or, one of the newer symmetrical
aerobatic airfoils the has a very large leading edge radius and the
maximum thickness very far forward. As of yet I've been unable to
locate and definitive aerodynamic studies of these 'foils.
In the homebuilt world many of the new "go-fast" designs use 6 series
airfoils. Dick Van Grunsven's RV series all use a 23013.
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/ | Dave Schwartz - Hewlett Packard, Spokane Division
/__ __ | P.O. Box 2500
/ / / / | Spokane, WA. 99220-2500
/ / /__/ |
/ | Internet: schw...@hpspkla.spk.hp.com
/ | Phone: (509)921-3648
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Stephens Akro - N31RS These opinions are strictly my own
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