Admin at 20:22, 3 May 2025

2025-05-03T20:22:31Z

@@ Line 60: / Line 60: @@
 {{Authority control}}
-{{DEFAULTSORT:Camber (Aerodynamics)}}
+[[Category:Camber]]
 [[Category:Aircraft aerodynamics]]
 [[Category:Aircraft wing design]]

Admin: 1 revision imported

2025-03-25T14:28:14Z

1 revision imported

← Older revision	Revision as of 07:28, 25 March 2025
(No difference)

wikipedia>Dolphin51: /* Overview */ Technical refinements.

2024-09-08T12:53:43Z

Overview: Technical refinements.

New page

{{Short description|Asymmetry between the two acting surfaces of an airfoil}}[[File:Aerodynamic camber.jpg|thumb|300px]]

In [[aeronautics]] and [[aeronautical engineering]], '''camber''' is the asymmetry between the two acting surfaces of an [[airfoil]], with the top surface of a wing (or correspondingly the front surface of a propeller blade) commonly being more convex ('''positive camber'''). An airfoil that is not cambered is called a ''symmetric airfoil''. The benefits of cambering were discovered and first utilized by [[George Cayley]] in the early 19th century.<ref>{{cite web
| title = Sir George Cayley—Making Aviation Practical
| first = Judy | last = Rumerman
| url = http://www.centennialofflight.net/essay/Prehistory/Cayley/PH2.htm
| website = [[Centennial of Flight Commission]]—History of Flight
| publisher = [[American Aviation Historical Society]]
| date = n.d.
| access-date = September 2, 2019
| quote = Experiments that he began to carry out in 1804 allowed him to learn more about aerodynamics and wing structures using a whirling arm device. Cayley observed that birds soared long distances by simply twisting their arched wing surfaces and deduced that fixed-wing machines would fly if the wings were cambered. This was the first scientific testing of airfoils as the part of the aircraft that is designed to produce lift.}}</ref>

==Overview==
Camber is usually designed into an [[airfoil]] to raise its maximum [[lift coefficient]] C<sub>Lmax</sub>. This minimizes the [[Stall (flight)|stalling]] speed of aircraft using the airfoil. An aircraft with wings using a cambered airfoil will have a lower stalling speed than an aircraft with a similar [[wing loading]] and wings using a symmetric airfoil.


One recent cambered design is called the [[supercritical airfoil]]. It is used for near-supersonic flight and produces a higher [[lift-to-drag ratio]] at near [[supersonic flight]] than traditional airfoils. Supercritical airfoils employ a flattened upper surface, highly cambered (curved) aft section, and greater leading-edge radius as compared to traditional airfoil shapes. These changes delay the onset of [[wave drag]].

==Definition==
An airfoil is said to have a positive camber if its upper surface (or in the case of a driving turbine or propeller blade its forward surface) is the more convex. Camber is a complex property that can be more fully characterized by an airfoil's '''camber line''', the curve ''Z(x)'' that is halfway between the upper and lower surfaces, and '''thickness function''' ''T(x)'', which describes the thickness of the airfoils at any given point. The upper and lower surfaces can be defined as follows:

: <math>
Z_\text{upper}(x)=Z(x)+\frac{1}{2}T(x)
</math>

: <math>
Z_\text{lower}(x)=Z(x)-\frac{1}{2}T(x)
</math>

===Example – An airfoil with reflexed camber line===
[[File:Reflex camber line.jpg|thumb|right|351px|An airfoil with reflex camber.]]
An airfoil where the camber line curves back up near the trailing edge is called a reflexed camber airfoil. Such an airfoil is useful in certain situations, such as with [[tailless aircraft]], because the [[moment (physics)|moment]] about the [[aerodynamic center]] of the airfoil can be 0. A camber line for such an airfoil can be defined as follows (''note that the lines over the variables indicates that they have been [[Nondimensionalization|nondimensionalized]] by dividing through by the chord''):

: <math>
\overline{Z}(x) = a\left[\left(b-1\right){\overline{x}}^3-b{\overline{x}}^2+\overline{x}\right]
</math>

An airfoil with a reflexed camber line is shown at right. The thickness distribution for a [[NACA airfoil|NACA 4-series airfoil]] was used, with a 12% thickness ratio. The equation for this thickness distribution is:

: <math>
\overline{T}(x) = \frac{t}{0.2}\left(0.2969\sqrt{\overline{x}}-0.1260\overline{x}-0.3516{\overline{x}}^2+0.2843{\overline{x}}^3-0.1015{\overline{x}}^4\right)
</math>

Where ''t'' is the thickness ratio.

== See also ==
* [[Chord (aircraft)|Chord]]
* [[NACA airfoil]]
* [[Aerodynamic drag]]
* [[Zero-lift axis]]

==References==
{{Reflist}}

;Sources
* [https://web.archive.org/web/20080804122746/http://www.desktopaero.com/appliedaero/airfoils1/airfoilgeometry.html ''Desktop Aerodynamics Digital Textbook'']. Retrieved 9/7/08.
* ''Theory of Wing Sections'', Ira H.Abbott and Albert E.Von Doenhoff (Dover Publications-1959) {{ISBN|0-486-60586-8}}

{{Authority control}}

{{DEFAULTSORT:Camber (Aerodynamics)}}
[[Category:Aircraft aerodynamics]]
[[Category:Aircraft wing design]]

Camber (aerodynamics) - Revision history

Admin at 20:22, 3 May 2025

Admin: 1 revision imported

wikipedia>Dolphin51: /* Overview */ Technical refinements.