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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:
The camber line is shown in red, and the thickness – or the symmetrical airfoil 0012 – is shown in purple. The simplest asymmetric foils are the NACA 4-digit series foils, which use the same formula as that used to generate the 00xx symmetric foils, but with the line of mean camber bent.
The mean camber line or mean line is the locus of points midway between the upper and lower surfaces. Its shape depends on the thickness distribution along the chord; The thickness of an airfoil varies along the chord. It may be measured in either of two ways: Thickness measured perpendicular to the camber line.
In case B above the thickness is measured perpendicular to the foil chord line. This is sometimes described as the "British convention" and can be seen in Bertin & Cummings 2009 [3]. Note that each definition implies a different camber line geometry for a given airfoil. Since the camber line curvature is small on most aircraft, the effect of ...
The profile was designed in 1922 by Virginius E. Clark using thickness distribution of the German-developed Goettingen 398 airfoil. [1] The airfoil has a thickness of 11.7 percent and is flat on the lower surface aft of 30 percent of chord. The flat bottom simplifies angle measurements on propellers, and makes for easy construction of wings.
Swept wings are a practical outcome of the desire to have a low thickness-to-chord ratio at high speeds and a lower one at lower speeds during takeoff and landing. The sweep stretches the chord as seen by the airflow, while still keeping the wetted area of the wing to a minimum. For practical reasons, wings tend to be thickest at the root ...
A rounded edge would behave as a blunt body in supersonic flight and thus would form a bow shock, which greatly increases wave drag. The airfoils' thickness, camber, and angle of attack are varied to achieve a design that will cause a slight deviation in the direction of the surrounding airflow. [3]
The mean camber line (or simply "camber line") is constituted by the midpoints of all airfoil cross-section segments perpendicular to the chord. Different definitions for the thickness Note that the thickness can be defined in several ways (see File:Airfoil thickness definition.svg). The so-called "British convention" is used here.