Airfoil
cross-sectional shape of a wing, blade (of a propeller, rotor, or turbine), or sail
An airfoil (American English) or aerofoil (British English) is a streamlined body that is capable of generating significantly more lift than drag. Wings, sails and propeller blades are examples of airfoils. Foils which work in a similar way submerged in water are called hydrofoils.
When oriented at a suitable angle, a solid body moving through a fluid deflects the passing fluid, resulting in a force on the airfoil in the direction opposite to the deflection. This force is known as an aerodynamic force and can be resolved into two components: lift (perpendicular to the freestream velocity) and drag (parallel to the freestream velocity).
The lift on an airfoil is primarily the result of its angle of attack. Most foil shapes require a positive angle of attack to generate lift, but cambered airfoils can generate lift at zero angle of attack. Airfoils have different shapes for different speeds: those for subsonic flight have a rounded leading edge, while those for supersonic flight tend to be slimmer. All have a sharp trailing edge.
The deflection of air by an airfoil generates a lower-pressure region above and behind itself.
This brief starts where responsible research should: with the source description of “Airfoil” as cross-sectional shape of a wing, blade (of a propeller, rotor, or turbine), or sail. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the general reference register because the source frames it as cross-sectional shape of a wing, blade (of a propeller, rotor, or turbine), or sail. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Sep 20, 2026. The linked authority identifier is Q4698744. The Library of Congress control number is sh85001301. None of the 1 selected statements returned an explicit reference.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
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The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Airfoil”, its source revision and the description used here.
- Expand the search: follow Airfoil primary sources, Airfoil archive and Airfoil research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Airfoil”?
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- Which cited source is closest to the event, object or claim?
Search terms from this dossier
This entry incorporates text from “Airfoil” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.