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Finding Airfoil Data For Amateur Projects?
An anonymous reader asks: "I am an aerospace engineering student who is engaged in an amateur project. A major hurdle I am having is finding modern airfoil data which can be used for a non-profit project. As most aerospace engineers know, just about all modern airfoil data are guarded industry secrets, so building an amateur project that requires precise airfoil data is difficult, because of the lack of available modern information. There is plenty of dated airfoil data from the 1960s or earlier, but my project requires access to modern data. Note that I do not have access to a wind tunnel to procure this data on my own. Where would one find free modern airfoil data for use in an amateur project?"
There's a great GPL'd program out there called XFoil that contains a large database of standard airfoils, including several "flat bottomed" foils, that are easy to construct from balsa.
I've used these before in some simple hobby projects (that never actually got finished)
have you flown on a plane? he's after some data about those big long things sticking out the sides of it.
NASA
If all this should have a reason, we would be the last to know.
Here's a pretty good site with coordinate data. I used it for a Catia model once. If you want data on the performance of the airfoil as well, such as polar curves, here is another site. Anyways, one thing to take note of is that not all modern airplanes use modern airfoils. For example, the Gulfstream GIV uses a modified NACA airfoil.
Do not go gentle into that good night. Rage, rage against the dying of the light.
Sailplanes are a good place to start. Get a copy of "Fundamentals of Sailplane Design" by Fred Thomas, printed by the college park press in MD. ISBN: 0966955307. It has a bunch of equations you are probably sick of (Stokes anyone?) and wing profiles and data for some gliders, including the Eta Uberglider.
If L/D is all you need, it should be easy, though there are some other numbers in the book that are probably useful. Good luck! Also, it never hurts to ask...Have you tried the military? Sometimes they give up random tidbits of data without a FOIA request.
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The book that I always pull off my shelf is the classic "Theory of Wing Sections" by Abbott and von Doenhoff (ISBN: 0486605868). It's a compilation of NACA data (NACA is NASA's predicessor) and the most comprehensive reference on the subject that I know of. Amazon has a new copy for $14.
I'm not sure why modern data would be a must for any non trans/supersonic vehicle (and some supersonic aircraft still use the classic NACA 4-digit airfoils).
This discussion (Free Hydro/Aero-Dynamic Software Simulators?) has some [maybe] useful links in it.
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Oh you get all worked up about an AC account, but I bet you didn't even vote in the last election.
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If you're close enough to come to Prescott, AZ I have a feeling my university (Embry-Riddle Aeronautical University) would let you peruse our hundreds of volumes of data that NASA has given us (some of it on airfoils).
I have encountered the same lack of current information and airfoil performance. I am a garage-engineer that produces experimental r/c aircraft somewhat regularly.
p ro files/NACA4.html
_ Gi nsberg/
I have found several gpl/shareware programs that do help design airfoils and predict their usability, but on a small scale for r/c. And the properties obviously change for real-world aircraft.
here are some links that may help though:
http://www.pagendarm.de/trapp/programming/java/
http://raphael.mit.edu/xfoil/
http://ourworld.compuserve.com/homepages/Harold
http://www.compufoil.com
http://www.profili2.com
http://www.ozemail.com.au/~malhardy/
These are applications that I have used with mixed success. And remember - most of these are for model aircraft so YMMV.
Also just google, there are lots of others out there who have run into the same situation and started the own projects to make data available.
Yeah... that would've been neat in 1902, maybe.
Airfoil follows fairly well-known laws of aerodynamics; I would wager that any modern use of airfoil data is an order of magnitude (time) more extensive in its demand for details...
What he wants is data - modern data - which means probably *lots* of data for modelling, analysis, on a very accurate scale.
; -- the corruption of government starts with its secrets. a truly free people keep no secrets. --
Until I googled, I had no idea what an 'airfoil' was, the word isn't in my English dictionary here in England.
Turns out he's just asking about Aerofoils but it's one of those words that the Americans spell wrong, like 'color' and 'potatoe'.
I suggest he tries all the places he already looked, but use the spelling the rest of the world uses.
A pizza of radius z and thickness a has a volume of pi z z a
It is very interesting that you call yourself an Aero Eng student, but haven't mentioned anything about the NACA series of aerofoils (or maybe that is what you are calling 1960s or earlier). Why modern aerofoil data is required, as opposed to these foils is not known. If you are on the cutting edge of design, then you should have ready access to a wind tunnel for testing. If you don't, then you should be able to convince your instructors to let you carry out a project to derive appropriate NACA data for your modern aerofoil.
A standard NACA series aerofoil should suffice for your project, until everything else related to the design is settled to maximum efficiency (propulsion and so on). The six series aerofoil is actually the basis for the F-15 wing, it uses the 64A modified with camber at the leading edge. A lot of modern aerofoils are derived from the six-series NACA aerofoils, so they would make for a great starting point, while you modify the design to meet your requirements.
If you really must use a custom design, I would reccomend using X Plane and the aircraft design module, and design the aerofoil within that module. This also allows flying of the model in the simulator. X Plane uses Finite Element Analysis to carry out the appropriate computations to work out if the design will work, and generate lift in accordance with design principles.
Building your own wind tunnel / test rig would also be a possibility, such as the Wright brothers did, in order to test your designs. A good read of
Aircraft Design: A Conceptual Approach by Daniel P. Raymer;
Aerodynamics for Naval Aviators by the USN ASA-ANA ISBN 1-56027-140-X;
Modern Combat Aircraft Design by Klaus Huenecke also explains the F-16 wing as the NACA 64A204 series (modified) - although these last couple of titles would probably gain unwanted attention now-a-days.
I remember being able to develop a decent approximation for the E-2C Hawkeye and the Concorde aerofoils as part of my assignments at Uni. Surely your Uni / College library would have suitable titles on the shelves with some more in-depth listings of aerofoils and their application, and the appropriate modifications. The NACA series aerofoil data should also be available online (at least I remember that used to be the case).
Good luck with your project, anyway.
InfoSec that matters, when it counts.
"Airfoil data" in this context is a summary of performance data over various airspeeds for a given wing cross-sectional shape. There are endless books of these in hard-copy, and they're absolutely critical if you want to design an airframe without having access to a wind tunnel or extensive prototyping facilities.
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Dr. Mark Drela @ MIT is a great resource for these things. He is also an RC Sailplane enthusiast, so that is where I know him from. He is one of the most knowledgeable, helpful guys around, and makes all of his airfoils available to the public.
w w.monkeytumble.com/dnc/supergee.htm
http://raphael.mit.edu/DRELA.bio.html
http://w
thelocust[dot]org