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Supercritical airfoils feature four main benefits: they have a higher drag-divergence Mach number, [21] they develop shock waves farther aft than traditional airfoils, [22] they greatly reduce shock-induced boundary layer separation, and their geometry allows more efficient wing design (e.g., a thicker wing and/or reduced wing sweep, each of which may allow a lighter wing).
, is the coefficient of lift of a specific section of the airfoil, t is the airfoil thickness at a given section, c is the chord length at a given section, is a factor established through CFD analysis: K = 0.87 for conventional airfoils (6 series), [4] K = 0.95 for supercritical airfoils.
9 Early and pre-World War II truck and buses. 10 See also. 11 References. 12 External links. ... This is a list of current and past vehicles and other products from ...
For example, the NACA 2412 airfoil has a maximum camber of 2% located 40% (0.4 chords) from the leading edge with a maximum thickness of 12% of the chord. The NACA 0015 airfoil is symmetrical, the 00 indicating that it has no camber. The 15 indicates that the airfoil has a 15% thickness to chord length ratio: it is 15% as thick as it is long.
English: Subsonic (1) and trans-sonic (2) airfoils at identical Mach number. A: Supersonic flow region . B: Shock wave . C: Area of stalled flow . On the trans-sonic (or supercritical) airfoil, the deceleration of the flow on the top surface, and the strength of the shockwave with which the flow returns to a subsonic regime, are reduced.
The supercritical airfoil is a type that results in reasonable low speed lift like a normal airfoil, but has a profile considerably closer to that of the von Kármán ogive. All modern civil airliners use forms of supercritical aerofoil and have substantial supersonic flow over the wing upper surface.
It addition, the wing was a new design, with a higher aspect ratio and supercritical airfoil. It was designed to compete with the Airbus A310 and Boeing 767, developed in the same era and of similar size. McDonnell Douglas worked with NASA on the aerodynamic design, and wind tunnel testing was conducted. [1]
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.