Aviation Stack Exchange
Aviation Stack Exchange

Questions tagged [airfoil]

The 2D shape of a section of aircraft wing.

An airfoil is the two-dimensional cross-section of a wing or other aircraft surface. It is generally shaped so that it provides lift to keep the aircraft in the air, but can also, or instead, be optimised to provide control, drag, or something else.

Different flight regimes have different optimal airfoil shapes.

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Are airfoil profiles patented? If not, why?

For something that takes so much research and can effect performance drastically, there seems to be no patents on airfoils. Too simple in appearance to patent? They appear simple at first but the performance characteristics behind them are quite…
usernamechecksout
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Why doesn't an airfoil rotate?

As far as I understand, two of the reasons how an airfoil generates lift are Coandă effect and downwash. However, if there is upwash near the leading edge, why isn't an airfoil rotated by the two forces (upwash at the front and downwash at the back…
Mun
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Should the pitching moment be up or down?

I had a question regarding the direction of the pitching moment. To make sure we are on the same page, here is what I know so far (please correct me if I am wrong). Lift acts through center of pressure Normally moment is taken around Aerodynamic…
T-REX
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Which design method is used for super critical airfoils?

How is an Airfoil categorized as super critical or not super critical? What are the ways to design a super critical airfoils?
Victor Juliet
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Does wash-out reduce drag?

I am in the process of designing a small wing (Re ~ 50-100k) and was planning to "un-twist" the tip of the foil by -5°. This corresponds to the 5° aoa where the center part of the wing has the highest Cl/Cd. I am aware that wash-out is mostly about…
fho
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What is the name of this airfoil?

Is there a general name for this type of airfoil? I'm having trouble finding any information on it so if anyone knows anything about it please let me know!
Lisa Ban
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What are Uses of thin airfoil and thick airfoil?

I have heard that thin airfoils are used for fast fyling and thick airfoil a are used for more lift. Is it true? Can you explain specific uses of thick and thin airfoils ?
Skyspy
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What is a "suction airfoil"?

I just stumbled upon this entry on airfoiltools.com: http://airfoiltools.com/airfoil/details?airfoil=griffith30symsuction-il There is basically no information there and (a quick cursory) web search did not yield anything useful. My search bubble…
fho
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Why am I seeing extremely high L/D ratio of (e.g. L/D = 90) in my 2D airfoil analysis?

Can anyone explain/justify why, using the 'Theory of Wing Sections' by ABBOTT the lift/drag ratios seem so high. For example, I'm doing an analysis of the NACA0012 airfoil and using their experimental data on pg462/463 at 8 degrees CL is roughly 0.9…
Barnaby
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What is the best airfoil for Edge 540 Style Aircraft?

I need help picking an airfoil. I'm an artist and have limited knowledge of such things. It's for a game with an aircraft similar to an Edge 540 / Extra 300. Unfortunately I have a limited selection of airfoils though and need some suggestions for…
Gullie667
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F.X Wortmann airfoil naming convention

Does anyone happen to have a reference or such that explains the naming convention used by Prof. Wortmann for his airfoils? Usually it follows that for symmetrical ones, the first 2 digits are to indicate the planned transition location at zero…
user46017
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How much lift do supercritical airfoils produce?

Compared to your regular asymmetric cambered airfoil, How much does lift do supercritical airfoils produce?
James Davis
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How does the airfoil pitching moment relate to center of pressure?

I've looked everywhere to find the answer and it's still unclear to me. How does pitching moment relate to center of pressure? Does it relate to coefficient of lift? I have made a carbon fiber wing (Eppler E423) and the CM of that wing is around…
user28729
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What airfoil simulation software is suitable for a cut trailing edge?

I'm looking for a way to simulate airfoils used to reduce turbulence. airfoiltools.com already does this a long way. However I have width and length limits, and I'm interested in comparing full profiles with profiles that are virtually longer but…
Carl R
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meanings of the numbers in the airfoil NACA 65(12)-10, where to find and plot

I am trying to plot an airfoil named NACA 65(12)-10 in javafoil. I found it in a few research articles. However, I am not sure from what series the airfoil is from. I tried looking it up on Airfoiltools website but to no avail. I am unsure if it is…
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