supercritical wing

supercritical wing

[¦sü·pər′krid·ə·kəl ′wiŋ]
(aerospace engineering)
A wing developed to permit subsonic aircraft to maintain an efficient cruise speed very close to the speed of sound; the middle portion of the wing is relatively flat with substantial downward curvature near the trailing edge; in addition, the forward region of the lower surface is more curved than that of the upper surface with a substantial cusp of the rearward portion of the lower surface.

Supercritical wing

A wing with special streamwise sections, or airfoils, which provide substantial delays in the onset of the adverse aerodynamic effects which usually occur at high subsonic flight speeds.

When the speed of an aircraft approaches the speed of sound, the local airflow about the airplane, particularly above the upper surface of the wing, may exceed the speed of sound. Such a condition is called supercritical flow. On previous aircraft, this supercritical flow resulted in the onset of a strong local shock wave above the upper surface of the wing (illustration a). This local wave caused an abrupt increase in the pressure on the surface of the wing, which may cause the surface boundary-layer flow to separate from the surface, with a resulting severe increase in the turbulence of the flow. The increased turbulence leads to a severe increase in drag and loss in lift, with a resulting decrease in flight efficiency. The severe turbulence also caused buffet or shaking of the aircraft and substantially changed its stability or flying qualities. See Aerodynamic force, Aerodynamic wave drag, Transonic flight

Supercritical airfoils are shaped to substantially reduce the strength of the shock wave and to delay the associated boundary-layer separation (illustration b). Since the airfoil shape allows efficient flight at supercritical flight speeds, a wing of such design is called a supercritical wing. See Airplane, Wing

supercritical wing

supercritical wing
A wing planform in which the upper surface is relatively flat and there is a more pronounced curvature on the lower surface. This permits a high cruising speed and carriage of increased payload.
References in periodicals archive ?
NASA also utilized modified F-8s for research on supercritical wing airfoils and digital fly-by-wire control systems.
The supercritical wing, winglets, fly-by-wire system, engine performance enhancements and composite materials used throughout the aircraft were all developed in partnership with NASA.
The Rockwell Sabreliner 65, nevertheless proved faster and more resistant than Fosset's airplane with its NASA engineered supercritical wing, making the plane all the more fuel-efficient.
Fairoz Assistant GM for Western Aviation."The Hawker 4000, with its sophisticated composite fuselage, supercritical wing, powerful Pratt & Whitney Canada FADEC-controlled engines and state-of-the-art Honeywell Primus EPIC avionics, simplifies the lives of busy executives and helps maximize their productivity.
Airbus owes much of its success to the supercritical wing design at Hatfield.
Described as the most significant aerodynamic contributor of the second half of the 20th century, the NASA Langley engineer's major accomplishments include area rule fuselage and supercritical wing designs.
Further, the FRCs have continued flight research work in tilt-rotor aircraft, fly-by-wire control systems, integration of computers into flight control systems, winglets, high angle-of-attack vehicles, high-maneuverability aircraft, supercritical wings, and space shuttle aerodynamics.