147:
409:
now turbulent, reattaches to the surface aft of the bubble; the increase in drag is not extreme in this condition. However, if AOA is increased to the stalling point, an adverse pressure gradient builds, and a shockwave can form within the thin boundary layer ahead of the bubble, even at relatively low speed. At the critical angle, the bubble rapidly expands ("bursts"), causing airflow to suddenly detach from the entire surface (from leading to trailing edge). The abrupt loss of lift is exacerbated by the lack of traditional stall "warning" or
31:
158:
205:. Aerodynamicists determined that, by appropriately shaping the airfoil used, the severity of these problems could be greatly reduced, allowing the aircraft to attain much higher speeds; this is the basis of the supercritical wing. Its design allows the wing to maintain high performance levels at speeds closer to Mach 1 than traditional counterparts.
253:, was ultimately cancelled due to a combination of technical challenges and relatively high costs. Despite this, the work was one aspect of the programme that survived the cancellation of its principal intended recipient. The supercritical airfoil shape was incorporated into the design of the supercritical wing.
354:
408:
behavior of supercritical profile is unlike that of low-speed airfoils. The boundary layer along the leading edge of a supercritical wing begins thin and laminar at cruise angles. As angle of attack (AOA) increases, this laminar layer detaches in a narrow region and forms a short bubble. The airflow,
125:
produced supercritical airfoils similar to
Kawalki's earlier work; these were used to devise a supercritical wing that was, in turn, incorporated into both civil and military aircraft. Accordingly, techniques learned from studies of the original supercritical airfoil sections have been used to design
391:
In addition to improved transonic performance, a supercritical wing's enlarged leading edge gives it excellent high-lift characteristics. Consequently, aircraft utilizing a supercritical wing have superior takeoff and landing performance. This makes the supercritical wing a favorite for designers of
180:
Berlin-Adlershof designed a number of airfoils characterised by elliptical leading edges, maximal thickness located downstream up to 50% chord and a flat upper surface. Testing of these airfoils was reported by B. Göthert and K. A. Kawalki in 1944. Kawalki's airfoil shapes were similar to those
229:
also conducted their own research efforts into optimal transonic airfoil designs, intending for these efforts to support civil aviation programmes. Up until the 1970s, there was considerable focus upon developing an airfoil that performed isentropic recompression, a shock-free return of the airflow
237:
functioned as an early aerial testbed for the supercritical wing, performing numerous evaluation flights during this period in support of the research effort. Following initial flight testing, the new airfoils were tested at increasingly higher speeds on another modified military aircraft, the
208:
In 1962 the
Vickers VC-10, which had wing super-critical characteristics, was rolled out. The VC-10 was the first airliner to have a wing section that was specifically designed for the plane (rather than a standard shape). The design was worked on by the Vickers and UK research institutes.
85:
laminar airfoil shapes. Standard wing shapes are designed to create lower pressure over the top of the wing. Both the thickness distribution and the camber of the wing determine how much the air accelerates around the wing. As the speed of the aircraft approaches the
384:, where the local flow velocity will be Mach 1. The position of this shockwave is determined by the geometry of the airfoil; a supercritical foil is more efficient because the shockwave is minimized and is created as far aft as possible, thus reducing
268:
airliners, both of which were developed during the 1970s. According to
Hirschel, Prem and Madelung, the supercritical wing has been regarded as being an essential element of modern jetliners, pointing towards its use on Airbus' product range.
213:, based in Hatfield, England, designed its own improved airfoil profiles, which were sometimes referred to as rooftop rear-loaded airfoils. Hawker Siddeley's research subsequently served as the basis for the supercritical wing of the
350:, a shock is required to recover enough pressure to match the pressures at the trailing edge. This shock causes transonic wave drag and can induce flow separation behind it; both have negative effects on the airfoil's performance.
345:
number, flow over the upper surface of an airfoil can become locally supersonic, but slows down to match the pressure at the trailing edge of the lower surface without a shock. However, at a certain higher speed, the
340:
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). At a particular speed for a given airfoil section, the
192:
During the 1950s and 1960s, a number of different high speed research aircraft equipped with conventional airfoils repeatedly encountered difficulties in breaking the sound barrier, or even reaching Mach 0.9.
185:. The aviation authors Ernst Heinrich Hirschel, Horst Prem, and Gero Madelung have referred to the supercritical airfoil as being of equal importance, in terms of aerodynamics, as the innovation of the
831:
Tanner, Clinton E., Bombardier
Business Aircraft Senior Advisor, "The Effect of Wing Leading Edge Contamination on the Stall Characteristics of Aircraft" (reported in 24 December 2018 article in
233:
In the United States, the supercritical airfoil was an area of research during the 1960s; one of the leading
American figures in the field was Richard Whitcomb. A specially modified
46: – area of separated flow. The supersonic flow over a supercritical airfoil terminates in a weaker shock, thereby postponing shock-induced boundary layer separation.
276:
specification that had been issued for the supercritical airfoil. Around this time, Kawalki's work was reportedly playing an active role in the design of new airliners, such as the
388:. Compared to a typical airfoil section, the supercritical airfoil creates more of its lift at the aft end, due to its more even pressure distribution over the upper surface.
98:
begin to form. The formation of these shockwaves causes wave drag. Supercritical airfoils are designed to minimize this effect by flattening the upper surface of the wing.
101:
The origins of the supercritical airfoil can be traced back to the German aerodynamicist K. A. Kawalki, who designed a number of airfoils during the
704:. Einspruch (1984) gegen US-Patentschrift NASA über »superkritische Profile«, basierend auf den Berechnungsmethoden von K. H. Kawalki (1940) p. 107.
912:
299:
The adoption of the supercritical airfoil amongst modern jet aircraft has diminished the use of some other methods of decreasing wave drag. The
146:
886:
657:
472:
256:
In such a manner, the technology has subsequently been successfully applied to several high-subsonic aircraft, noticeably increasing their
832:
289:
135:
904:
871:
701:
428:"prevent the entire wing from stalling at once", they may also form an alternative means of providing recovery in this respect.
967:
982:
369:
axis: position along chord, leading edge left). The sudden increase in pressure coefficient at midchord is due to the shock.
962:
987:
850:
992:
303:
was one such method, having also been derived from
Richard Whitcomb's work as well as that of the German aerodynamicist
393:
347:
329:
726:
234:
392:
cargo transport aircraft. A notable example of one such heavy-lift aircraft that uses a supercritical wing is the
105:. Following the end of the conflict, multiple nations continued research into the field, including Germany, the
632:
312:
210:
114:
548:"A comparison of wing pressure distributions measured in flight and on a windtunnel model of the super VC. 10"
281:
177:
811:
307:. Alternatively referred to as "Whitcomb bodies" or "Küchemann carrots", it is closely associated with the
405:
835:
749:
934:
74:
304:
34:
Conventional (1) and supercritical (2) airfoils at identical free stream Mach number. Illustrated are:
30:
917:
374:
246:
605:
Palmer, Willam E. and Donald W. Elliott, "Summary of T-2C Supercritical Wing
Program", NASA SP-301
447:
416:
Due to this lack of buffet warning, aircraft using supercritical wings are routinely equipped with
280:. Additionally, some aircraft have been redesigned to incorporate supercritical wings; such as the
245:
While the supercritical airfoil had been initially worked on by NASA as part of the United States'
182:
165:
150:
122:
665:
117:
designed a number of advanced airfoils that were, amongst other programmes, incorporated into the
437:
487:
926:
900:
882:
867:
697:
272:
During 1984, Kawalki's research was cited as the basis for a formal objection against the US
957:
851:"NAVAIR 00-80T-80, Aerodynamics for Naval Aviators". Naval Air Systems Command, 1965, p. 86.
547:
285:
173:
102:
300:
293:
257:
161:
410:
385:
337:
172:
The supercritical airfoil was first suggested by aerodynamicists in
Germany during the
106:
87:
27:
Airfoil designed primarily to delay the onset of wave drag in the transonic speed range
157:
976:
342:
110:
764:
442:
421:
417:
239:
82:
78:
522:
73:
Supercritical airfoils are characterized by their flattened upper surface, highly
17:
618:
Andrews, William H., "Status of the F-8 Supercritical Wing
Program", NASA SP-301
373:
At a certain point along the airfoil, a shock is generated, which increases the
358:
333:
277:
250:
226:
214:
127:
118:
91:
866:
Gunston, Bill. "Airbus, the
Complete Story." 2nd ed., Haynes Publishing, 2009.
249:
programme, the supersonic airliner that was being developed to harness it, the
425:
265:
261:
194:
186:
131:
930:
637:
Turning Point 7: A Bumpy Ride: Seattle's Economic Booms, Busts and Comebacks
308:
218:
202:
198:
197:
airflow over the upper surface of the traditional airfoil induced excessive
95:
67:
63:
126:
airfoils for several high-speed subsonic and transonic aircraft, from the
336:
farther aft than traditional airfoils, they greatly reduce shock-induced
696:
Hans-Ulrich Meier, Die Pfeilflügelentwicklung in Deutschland bis 1945,
353:
222:
59:
620:
Supercritical Wing Technology: A Progress Report on Flight Evaluations
607:
Supercritical Wing Technology: A Progress Report on Flight Evaluations
328:
Supercritical airfoils feature four main benefits: they have a higher
273:
546:
Browne, G. C.; Bateman, T. E. B.; Pavitt, M.; Haines, A. B. (1972).
879:
Aeronautical Research in Germany : From Lilienthal until Today
311:, a recent innovation of the era to minimise wave drag by having a
473:"NASA Supercritical Airfoils: A Matrix of Family-Related Airfoils"
352:
156:
145:
292:
model that adopted a new one-piece supercritical wing to improve
818:
296:
by delaying the rise in drag and increasing lift-to-drag ratio.
968:
The Supercritical Airfoil at NASA Dryden Flight Research Center
877:
Hirschel, Ernst Heinrich; Prem, Horst; Madelung, Gero (2012).
315:
area which changes smoothly along the length of the aircraft.
424:
recovery systems, to meet certification requirements. Since
963:
Supercritical airfoil at US Centennial of Flight Commission
925:(3693). London, UK: Reed Business Information: 2127–2142.
209:
Between 1959 and 1968, the British aerospace manufacturer
365:
axis: Mach number, or pressure coefficient, negative up;
633:"The Online Encyclopedia of Washington State History"
552:
Aeronautical Research Council Reports & Memoranda
181:
subsequently produced by the American aerodynamicist
221:
airliner which first flew during 1972. In parallel,
201:, as well as a form of stability loss known as
90:, the air accelerating around the wing reaches
503:Hirschel, Prem and Madelung 2012, pp. 184-185.
592:
590:
588:
8:
77:("downward-curved") aft section, and larger
38: – supersonic flow region,
881:. Heidelberg: Springer Berlin Heidelberg.
678:Hirschel, Prem and Madelung 2012, p. 390.
596:Hirschel, Prem and Madelung 2012, p. 185.
582:Hirschel, Prem and Madelung 2012, p. 120.
512:Hirschel, Prem and Madelung 2012, p. 389.
62:designed primarily to delay the onset of
897:Aerodynamic Design of Transport Aircraft
29:
911:Warwick, Graham (23–29 December 1979).
463:
958:Supercritical Airfoils at Aerospaceweb
413:as a low-speed contour would provide.
178:Deutsche Versuchsanstalt für Luftfahrt
176:. During 1940, K. A. Kawalki at
7:
833:Aviation Week & Space Technology
136:McDonnell Douglas AV-8B Harrier II
25:
748:Reis, Ricardo (1 December 2014).
658:"The Nation: Showdown on the SST"
622:. NASA, February 1972. pp. 49–58.
121:. In America, the aerodynamicist
765:"Richard Whitcomb's Triple Play"
288:, which had a second generation
837:Thin Margins in Wintry Takeoffs
750:"Coca-Cola bottles and carrots"
361:/pressure coefficient diagram (
42: – shock wave,
471:Harris, Charles (March 1990).
1:
789:, p. 622. McGraw-Hill, 2001.
664:. 29 May 1971. Archived from
260:. Early examples include the
247:National Supersonic Transport
787:Fundamentals of Aerodynamics
716:Warwick 1979, p. 2127.
609:, February 1972. pp. 13–34.
448:Vought F-8 Crusader (TF-8A)
394:Boeing C-17 Globemaster III
348:drag-divergence Mach number
330:drag-divergence Mach number
235:North American T-2C Buckeye
168:Supercritical Wing Airplane
58:in American English) is an
1009:
564:Gunston 2009, pp. 28, 51.
284:, popularly known as the
164:before his flight on the
913:"AV-8B Advanced Harrier"
211:Hawker Siddeley Aviation
189:to high speed aircraft.
115:Hawker Siddeley Aviation
282:Hawker Siddeley Harrier
812:"C-17 Globemaster III"
727:"NASA and the Jet Age"
377:to the critical value
370:
357:Supercritical airfoil
169:
154:
52:supercritical aerofoil
47:
983:Aircraft aerodynamics
752:. upmagazine-tap.com.
668:on December 21, 2008.
400:Stall characteristics
356:
160:
149:
81:radius compared with
56:supercritical airfoil
33:
988:Aircraft wing design
918:Flight International
763:Hallion, Richard P.
729:. airandspace.si.edu
480:NASA Technical Paper
375:pressure coefficient
230:to subsonic speeds.
166:Vought F-8A Crusader
993:American inventions
687:Obert 2009, p. 251.
573:Obert 2009, p. 251.
493:on 18 October 2011.
438:Whitcomb area rule
371:
305:Dietrich Küchemann
294:cruise performance
217:, a multinational
170:
155:
48:
18:Supercritical wing
899:IOS Press, 2009.
888:978-3-642-18484-0
849:Hurt, H. H. Jr.,
767:. airforcemag.com
134:airliners to the
113:. In particular,
16:(Redirected from
1000:
946:
944:
942:
933:. Archived from
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492:
486:. Archived from
477:
468:
290:AV-8B Harrier II
286:Harrier jump jet
225:Germany and the
183:Richard Whitcomb
174:Second World War
123:Richard Whitcomb
103:Second World War
21:
1008:
1007:
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1001:
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937:on 8 March 2012
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332:, they develop
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313:cross-sectional
301:anti-shock body
258:fuel efficiency
162:Thomas McMurtry
144:
28:
23:
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12:
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952:External links
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107:United Kingdom
88:speed of sound
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523:"Wing design"
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111:United States
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83:NACA 6-series
80:
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71:
70:speed range.
69:
65:
61:
57:
53:
45:
41:
37:
32:
19:
939:. Retrieved
935:the original
922:
916:
896:
878:
860:Bibliography
845:
836:
827:
806:
798:
794:
786:
781:
769:. Retrieved
758:
743:
731:. Retrieved
721:
712:
692:
683:
674:
666:the original
661:
652:
640:. Retrieved
636:
627:
619:
614:
606:
601:
578:
569:
560:
551:
541:
530:. Retrieved
527:www.vc10.net
526:
517:
508:
499:
488:the original
483:
479:
466:
443:NACA airfoil
422:stick-pusher
418:stick-shaker
415:
403:
390:
378:
372:
366:
362:
327:
298:
271:
255:
244:
232:
207:
191:
171:
100:
79:leading-edge
72:
55:
51:
49:
43:
39:
35:
895:Obert, Ed.
821:. May 1998.
706:(in German)
426:wing fences
359:Mach number
334:shock waves
319:Description
278:Airbus A310
251:Boeing 2707
227:Netherlands
215:Airbus A300
128:Airbus A310
119:Airbus A300
977:Categories
853:at faa.gov
771:1 February
532:2023-02-03
454:References
420:alert and
266:Boeing 767
262:Boeing 757
195:Supersonic
187:swept wing
151:NASA TF-8A
132:Boeing 777
109:, and the
96:shockwaves
931:0015-3710
801:: p. 623.
459:Citations
309:area rule
219:wide-body
203:Mach tuck
199:wave drag
138:jumpjet.
68:transonic
64:wave drag
432:See also
324:Benefits
75:cambered
941:22 July
733:27 June
642:7 March
223:postwar
153:in 1973
142:History
66:in the
60:airfoil
929:
903:
885:
870:
700:
411:buffet
382:p-crit
274:patent
94:1 and
815:(PDF)
799:ibid.
491:(PDF)
476:(PDF)
406:stall
943:2011
927:ISSN
901:ISBN
883:ISBN
868:ISBN
819:NASA
773:2010
735:2020
698:ISBN
662:TIME
644:2011
484:2969
404:The
386:drag
264:and
130:and
92:Mach
923:116
979::
921:.
915:.
840:).
817:.
660:.
635:.
587:^
550:.
525:.
482:.
478:.
396:.
242:.
50:A
945:.
907:.
891:.
775:.
737:.
646:.
554:.
535:.
379:C
367:x
363:y
54:(
44:C
40:B
36:A
20:)
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