Document
[111 4,093,156
United States Patent [191
1451 June 6, 1978
Coe, Jr.
3,884,435 5/1975 Cory et a l . ............................. 244/46
[54] SUPERSONIC TRANSPORT
12/1975 Mederer ............................ 24/45 A
3,926,389 [75] Inventor: Paul L . Coe, Jr., Yorktown, Va.
Primary Examiner-Trygve M. Blix [73] Assignee: The United States of America as Assistant Examiner-Charles E. Frankfort represented by the Administrator of Attorney, Agent, or Firm-Howard J. Osborn; John R.
the National Aeronautim and Space Manning; Wallace J. Nelson Administration, Washington, D.C.
[571 ABSTRAa [21] Appl. No.: 718,244 An aircraft of supersonic transport configuraton featur- [22] Filed: Aug.27,1976 ing thrust vectoring in conjunction with wing apex segments used as canard surfaces during take-off, land-
[51] Int. C1.z ........................... B64C 3/08; B64C 5/04
ing, and low-speed flight. The angle of incidence of the [52] U . S . C 1 . .................................... 244/45 A; 244/46; wing apex segments, when the segments are functioning 244/218 as canard surfaces, is variable with respect to the air- [58] Field of Search ................... 244/43, 46, 45 A, 48, craft angle of attack. The wing apex segments further- 244/56,201,218 more form a portion of the main wing panel swept [561 References Cited leading edge when not functioning as canard surfaces.
The combination of thrust vectoring and deployable U . S . PATENT DOCUMENTS wing apex segments results in increased aircraft range
3,069,115 12/1962 Strang .................................... 244/43
and improved low-speed longitudinal stability while
3,447,761 6/1969 Whitener et al. ...................... 244/46
providing acceptable take-off length capabilities.
3,642,234 2/1972 Kamber et al. .................... 244/45 A
3,730,458 VI973 Habcrkorn ............................. 244/47
3,738,595 6/1973 Bouchnik ............................... 244/43 5 Claims, 6 Drawing Figures 1 4 , J I3
1 . - 3
U. S.Patent June 6, 1978 Sheet 1 of 2 4,093,156
(u M
a a
l
(D M
U. S. Patent June 6,1978 Sheet 2 of 2
4,093,156
FIG. 2
FIG. 4 4
FIG. 5
FIG. 6
4,093,156
1 2
A still further object is to provide canard surfaces for SUPERSONIC TRANSPORT low speed longitudinal stability while maintaining an aircraft configuration providing efficient supersonic ORIGIN OF THE INVENTION cruise.
The invention described herein was made by an em- 5 SUMMARY OF THE INVENTION ployee of the United States Government and may be These and other objects of the present invention are manufactured and used by or for the Governmental for achieved by providing a supersonic transport, having governmental purposes without the payment of any the highly swept arrow wing configuration, with de- royalties thereon or therefor.
10 flectable jet exit nozzles to provide thrust vectoring and BACKGROUND O F THE INVENTION movable wing apex segments which act as canard sur- - - - Wind tunnel investigations of supersonic transport faces.
configurations having highly swept arrow wings indi- Studies have shown that the application of thrust cate that high levels of aerodynamic efficiency can be vectoring concepts, the deflection ofjet exit nozzles and obtained at Mach numbers on the order of 2.7. Further- 15 consequently thrust downward, provides significant more, the investigations indicate that minimum trim improvements in take-off lift characteristics. Specifi- drag at supersoni~ speeds can be obtained by position- cally, the take-off lift coefficient can be increased from ing the aircraft center-of-gravity relatively far aft. approximately 0.55 to approximately 0.7, and this can be However, such configurations exhibit relatively poor accomplished at a reduced angle of attack. The in- low-speed characteristics. In particular, the highly- 20 creased take-off lift coefficient reduces wing area and swept arrow wing configuration exhibits a compara- installed thrust requirements, permitting an improved tively shallow liftcurve slope which, when coupled match between the engine and the airframe which re- with the aircraft t a i l scrape angle, limits take-off lift sults in an increase in range while maintaining accept- coefficients to values of approximately 0.55. Further- able aircraft take-off field length capabilities. Moreover, more, for this take-off lift coefficient of 0.55 to be 25 the reduced angle of attack permits elimination of the achieved, a fairly high angle of attack is necessary “visor” nose requirement and allows reductions in the which constrains airframe design to inclusion of both a length of the landing gear, such modifications repre- “visor”-type nose, to provide acceptable pilot visibility, senting significant volume and weight savings.
and an elongated landing gear installation to maximize The elements constituting the other major compo- tail scrape angle. Moreover, this high angle of attack 30 nent of the present invention are movable wing apex results in a significant increase in drag imposing penal- segments, structures highly compatible with both the ties on low-speed performance. supersonic transport configurations and the application The most significant penalty involves the take-off of powered lift. The wing apex segments are hinged so field length constraint. In order to provide acceptable as to be separable from the main wing by forward rota- take-off field lengths, the conventional highly-swept 35 tion i n the wing plane thus forming aerodynamically arrow wing configuration requires a wing area and independent canard surfaces. Their deployment effec- installed thrust substantially above that required to pro- tively removes the wing apex to create a more linear vide efficient supersonic cruise. As a consequence, air- variation in pitching moment with respect to angle of craft range is forfeited. attack over a larger range of angles by preventing the The second problem, encountered in the low-speed 40 formation of wing apex vortices as previously men- flight regime, is the nonlinear variation of pitching mo- tioned. Rotation of the wing apex segments rearward to ment with respect to angle of attack. There is a ten- constitute an integral part of the highly swept wing dency for the aircraft to pitch up due to the formation of surfaces creates an aircraft configuration having the vortices at the wing apex as the aircraft angle of attack desired minimum trim drag for efficient supersonic is increased. 45 cruise.
The third significant problem associated with such In addition to their deployment capability, the wing configurations is the forward shift in aerodynamic cen- apex segments are furthermore angularly positionable ter as the aircraft speed goes from supersonic to sub- such that their angle of incidence is variable relative to sonic. Where the aircraft centersf-gravity is positioned aircraft angle of attack. Thus, the deployed wing apex to provide minimum trim drag at design Mach numbers 50 segments minimize one drawback associated with the of approximately 2.7, the shift in aerodynamic center to application of thrust vectoring to supersonic transport a more forward position at low speeds induces longitu- configurations. Specifically, thrust vectoring shifts the vector component of thrust aft of aircraft center of dinal instability.
It is therefore an object of the present invention to gravity during take-off creating a large negative, or increase take-off lift at a reduced angle of attack. 55 nose down pitching moment. By selectively positioning Another object of the present invention is to apply the angle of incidence of the deployed wing apex seg- thrust vectoring concepts to increase take-off lift. ments to provide a large lift component forward of A further object of the invention is to offset the pitch- aircraft center of gravity during take-off, the undesir- ing moment induced by thrust vectoring. able nose down pitching moment created by thrust An additional object is to eliminate the nonlinear 60 vectoring is cancelled out.
variation in pitching moment as related to angle of Moreover, the deployment and selective positioning attack. of the wing apex segments in conjunction with thrust A further additional object i s to restrain the forma- Vectoring minimizes another problem associated with tion of wing apex vortices which cause nonlinear varia- supersonic transport configurations. A reduction in tions in pitching moment with respect to aircraft angle 65 flight speed from supersonic to subsonic is accompanied of attack. by a forward shift in aircraft aerodynamic center, induc- ing longitudinal instability. Selectively positioning the Another additional object is to provide longitudinal w h g apex segments SO that their angle of incidence stability at low speeds.
4,093,156
3 4
produces a variable lift component and the jet exit noz- includes a root section 23 adjacent the side of fuselage zles so that their angle of declination increases the posi- 12 and a tip 24 disposed outboard of the root section 23.
tive lift component of the thrust vector tends to restore The forward extremity of root section 23 is positioned longitudinal stability to the aircraft in its initial trim somewhat aft of nose 13 and forward of the longitudinal condition.
5 midpoint station of fuselage 12. The spanwise length of A more complete appreciation of the invention and each main wing panel 22 between the root section 23 many of the attendant advantages thereof will be and the tip 24 is on the order of about four times the readily apparent as the same becomes better understood maximum width of fuselage 12.
by reference to the following detailed description when Each main wing panel 22 has a forward notched edge considered in connection with the accompanying draw- 10 21 and a leading edge 25 swept back at an angle of the ings wherein: order of about 14“ connecting the forward extremities of root section 23 and tip 24 thereof, and a trailing edge BRIEF DESCRIPTION O F THE DRAWINGS 26 connecting the aft extremities of the root and tip FIG. 1 is a plan view of the powered-lift supersonic sections.
cruise aircraft of the present invention with the wing 15 An outboard wing panel 36 is integrally secured to apex segments retracted so as to be an integral part of each main wing panel a tip 24 thereof. The leading edge the aircraft wing planform; 37 of each outboard panel 36 extends outwardly and FIG. 2 is a plan view of the aircraft of the present rearwardly from the point at which panel 36 connects invention with the wing apex segments deployed as with main wing panel 22 to thereby provide a notched canard surfaces separate from the main wing; 20 leading edge continuation thereof. Each outboard wing FIG. 3 is a side view of the aircraft showing the wing panel 36 is also provided with a straight trailing edge 38 apex segments deployed as canard surfaces with the which extends outwardly and rearwardly from trailing angle of incidence varied from aircraft angle of attack; edge of panel 22. A pair of vertical fin or tail stabilizers FIG. 4 is a section taken at 4-4 of FIG. 1 of the 39 are integrally connected to main wing panel 22 and elements of the wing apex segments in the undeployed 25 outboard wing panel 36 at the notched inner connection position; thereof.
FIG. 5 is a section taken at 5-5 of FIG. 2 of the As mentioned hereinbefore, an inboard engine nacelle elements of the wing apex segment in the deployed 17 and an outboard engine nacelle 18 are located be- position; and neath each wing 20. A thrust vectoring nozzle 29 is FIG. 6 is a section taken at 6-6 of FIG. 1 showing 30 hingedly connected to each nacelle 17 and 18 in a con- the configuration of the tip of the wing apex segment ventional manner and conventional actuator means (not and the main wing panel at their juncture. shown) are provided for positioning the nozzles 29 in unison at an angle between --2” and -22” with respect DETAILED DESCRIPTION to the wings to thereby direct engine thrust resulting in Referring now to the drawings wherein like refer- 35 an increased lift coefficient across a range of aircraft ence numerals designate identical parts throughout the angles of attack.
several views, there is shown a fued swept-wing plan- As mentioned hereinbefore, wing 20 is provided with form aircraft, generally designated by reference nu- wing apex segments 40 forwardly disposed and extend- meral 11. Aircraft 11 is provided with a fuselage 12 ing along an initial length of swept leading edges 25. In having a length-to-equivalent-diameter,or fineness ratio 40 the undeployed position shown in FIG. 1, wing apex suitable for supersonic flight, and including a right-cir- segments 40 form an integral portion of the wing aero- cular conical nose 13 at the forward end thereof and dynamic surface creating a highly swept arrow plan- terminating in a conical tip 14 at the aft end thereof. A form. As shown in FIG. 4, a section taken along 4-4 of suitable control compartment or pilot’s cabin 15 is also FIG. 1, each wing apex segment 40 consists of leading included in the nose 13 of fuselage 12. A conventional 45 member 42, midmember 43 and trailing member 44 empennage assembly including a vertical stabilizer 31 stacked in the undeployed or stowed position to form a and swept horizontal stabilizers 32 is provided project- cross-section complimenting that of the leading edge 25 ing outwardly from the aft end of fuselage 12. The of main wing section 22. Flap 45, hingedly attached to airfoil sections of these stabilizer members 31 and 32 are leading member 42, is deployed in this stowed position preferably taken from the supersonic family of symmet- SO to more completely achieve the desired cross-section.
rical thin airfoils. As shown in FIG. 6, a section taken along 6-6 of FIG.
Aircraft 11 is provided with a wing, generally desig- 1, notched edge 21 of main wing panel 22 forms a nated by numeral 20, projecting substantially horizon- curved aerodynamic leading edge for smooth air flow tally outward from each side of the fuselage 12 aft of when wing apex segments 40 are deployed as canard nose 13 and terminating forward of conical tip 14. AS 55 surfaces. Additionally, tips 46 of each leading member will be further explained hereinafter, a pair of engine 42 of wing apex segments 40 have a curved tapered nacelles 17 and 18 are fixedly attached to each wing 20. portion, as shown in FIG. 6, which permits a smooth In the preferred embodiment, aircraft 11, as shown in transition in the stowed position between wing apex FIG. 3 is of the arrow, low-wing type with the upper segments and wing panels.
surface of wings 20 being substantially flush with the 60 Wing apex segments 40 are pivotally connected to midline of fuselage 12, although mid- and high-wing fuselage 12 in a conventional manner and actuator arrangements are also considered to fall within the means (not shown) are provided for forwardly deploy- scope of the present invention. ing wing apex segments 40 as independent canard sur- Each wing 20 includes a main wing panel 22 fvredly faces separate from main wing panels 22 as shown in interconnected with fuselage 12, and a forwardly dis- 65 FIG. 2. In the deployed position shown in FIG. 5, a posed wing apex segment 40, later described in detail, section taken along 5-5 of FIG. 2, each wing segment extending along an initial portion of the swept leading 40 forms a high lift canard surface by the repositioning edge 25 of main wing panel 22. Each wing panel 22 of leading member 42, midmember 43, and trailing 4,093,156 C
0 6
member 44 relative to one ‘another while flap 45 is re- canard surfaces effectively removes the apex of wing 20 tracted to a position proximate with the underside of the which significantly delays the onset of wing vortex leading edge of leading member 42 to more completely formation resulting in a substantially linear variation in achieve the desired cross-section.
pitching moment as aircraft angle of attack is increased.
Wing apex segments 40 are furthermore rotatably During supersonic phases of flight, wing apex seg- connected to fuselage 12 by conventional means for ments 40 are retracted to the positions shown in FIG. 1.
movement within a range of 10” declination to 20” incli- This operation involves the reorientation of leading nation with respect to the centerline of fuselage 12.
member 42, midmember 43 and trailing member 44 into Actuator means (not shown) are provided for altering a “stacked” relationship and the deployment of flap 45 the position of the wing apex segments 40 in unison such 10 to produce the cross section shown in FIG. 4 compli- that their angle of incidence can be varied relative to the menting that of the leading edge 25 of main wing sec- angle of attack of main wing panels 22. By so doing, a tion 22. The blending of the wing apex segments 40 with lift component of varying magnitudes can be generated main wing panel 22 is enhanced by the shape of apex forward of aircraft center of gravity 50.
segment tip 46, as shown in FIG. 6. Furthermore, thrust The actual construction of the wing apex segments vectoring nozzles 29 are positioned at substantially 2” pivotal connection as well as the control mechanisms declination with respect to wings 20. These operations and actuators to effect both forward deployment of result respectively in the formation of an aerodynamic members 42, 43 and 44 and the rotation of wing apex wing surface complimentary to efficient supersonic segments 40 as canard surfaces have been omitted in the cruise flight and the provision of maximum aircraft interest of clarity, inasmuch as these details are consid- 20 forward thrust.
ered conventional components and well known in the As the speed of the aircraft drops from supersonic to art.
subsonic, a shift in aerodynamic center occurs. In the preferred embodiment, aircraft center of gravity 50, OPERATION shown in FIG. 1, is located at approximately 53.8 per- In operation the present invention fully exploits the 25 cent of the wing mean chord length ( c ) 53. As illustrated advantages inherent in highly swept arrow wing config- in FIG. 3, aircraft aerodynamic center shifts forward uration at supersonic speeds and provides components from cruise location 51, at approximately 57.1 percent c, which minimize the disadvantages of this configuration to low speed location 52, at approximately 51 percent c.
during take-off and low-speed flight regimes.
The longitudinal instability associated with this forward During take-off, thrust vectoring nozzles 29 con- 30 shift is counteracted by employing thrust vectoring in nected to each engine nacelle 17 and 18 are deflected combination with wing apex segment deployment and downward in unison as shown in FIG. 3. This results in positioning to restore the aircraft to its initial trim con- take-off lift coefficient of 0.7 as compared to 0.55 for a dition. In so doing, nozzles 29 are rotated downward similar configuration not utilizing thrust vectoring. The from a cruise declination of approximately 2” with re- increased value of the take-off lift coefficient reduces 35 spect to the wings to produce a greater positive lift the wing area and installed thrust requirements permit- component behind aerodynamic center 52. Simulta- ting an improved match between engine and airframe neously, members 42,43,44 and 45 forming each wing which, in turn, results in approximately a 12.5% in- apex segment 40 are forwardly deployed from the crease in range while still providing acceptable take-off stacked cruise positions shown in FIGS. 1 and 4 to the 4 0 field length capabilities. Furthermore, this high take-off relative positions shown in FIGS. 2 and 5 to form ca- lift coefficient can be achieved at a reduced angle of nard surfaces. Following deployment at a “no-lift” attack. The reduced angle of attack eliminates the ne- angle of incidence, wing apex segments 40 are angularly cessity of a “visor” nose and also reduces the length of positioned to produce a variable lift component forward the landing gear with respect to that utilized in contem- of center of gravity 50.
porary supersonic transport configurations. 45 From the foregoing description, it is readily apparent During takeoff, wing apex segments 40 are deployed that the applicant has developed an aircraft utilizing a as in FIG. 2, the relative positions of leading member combination of components which fully exploit the 42, midmember 43, trailing member 44 and flap 45 being favorable characteristics of a highly swept arrow plan- as shown in FIG. 5. Furthermore, thrust vectoring form as it applies to supersonic flight regimes and which nozzles 29 are positioned at substantially 22” declination 50 minimize the unfavorable characteristics evidenced in with respect to wings 20. The thrust vectoring results in such configurations during take-off, subsonic and tran- a large negative, or nose down pitching moment since sonic flight regimes. Obviously, many modifications the vector component of thrust 54 passes aft of the and variations of the present invention are possible in center of gravity 50. By deploying wing apex segments the light of the above teachings. It is to be understood, 40 as canard surfaces and angularly positioning them to 55 therefore, that the foregoing disclosure relates only to a produce a forward positive lift component of desired specific embodiment of the invention, and that numer- magnitude, a positive, or nose-up pitching member is ous modifications, variations and uses of the present generated which cancels the negative pitching moment invention are possible in the light of the above teach- introduced by thrust vectoring.
ings, as will be readily apparent to those skilled in the During the subsonic and transonic phases of flight, art without departing from the spirit and scope of the wing apex segments 40 remain deployed in the forward present invention as set forth in the appended claim.
position shown in FIG. 2 thereby forming independent What is claimed as new and desired to be secured by aerodynamic canard surfaces for the aircraft. Contem- Letters Patent of the United States is: porary supersonic transport configurations have a char- 65 1. An aircraft having supersonic flight capabilities acteristic non-linear variation in pitching moment with comprising: respect to aircraft angle of attack due to the formation a fuselage having a fineness ratio suitable for super- of wing apex vortices as the aircraft angle of attack is sonic flight; increased. Deployment of wing apex segments 40 as
4,093,156
I 8
a wing connected to each side of said fuselage and means for selectively positioning said wing apex seg- projecting outwardly therefrom, each said wing ments and segmented members so that their angle including: of incidence produces a variable forward lift com- (a) a main wing panel having a relatively thick ponent providing artificial longitudinal stability to swept leading edge and a relatively thin trailing 5 said aircraft in its initial trim condition.
edge, said main wing panel having notched lead- 2. The aircraft of claim 1 wherein said notched lead- ing edge means for receiving a movable wing ing edge means of each said main wing panel has a apex segment in its stowed position; curved aerodynamic leading edge for smooth airflow the wing apex segment forming a forward exten- about said main wing panel when said wing apex seg- sion of the swept leading edge of said main wing 10 ment is in the deployed position.
panel in the stowed position for efficient super- 3. The aircraft of claim 1 wherein each said wing apex sonic cruise, said wing apex segment being sepa- segment includes a curved tapered tip for smooth transi- rable from said wing and both pivotal and rotat- tion between said notched leading edge means of said able to a deployed position such that said wing main wing panel and said wing apex segment in the apex segment acts as an independent aerody- 15 stowed position to create an aerodynamic surface con- namic surface providing a lift component to said ducive to efficient supersonic flight.
aircraft forward of said main wing panel, said 4. The aircraft of claim 1 wherein each said wing apex wing apex segment being further segmented into segment is comprised of a plurality of said members members to obtain desired sectional configura- each having a cross-section complimentary to that of tions; the wing apex segment providing a sub- 20 the other said members and the relative position of each stantially linear variation in aircraft pitching said member being alterable with respect to the other moment with resDect to aircraft angle of attack said members in such a manner that in the dedoved I by suppressing t i e formation of wing apex verti- position said plurality of members are positiongd s ; b - ces when the wing apex is in a deployed position; stantially in line, the composite cross-section thereby at least one engine nacelle affied beneath each said 25 provided forming an aerofoil; and in such a manner that wing and terminating substantially at the trailing in the stowed position said plurality of members forms a edge thereof; an engine contained in each said na- substantially stacked configuration the composite cross- celle for producing thrust; and jet exit nozzles section thereby provided complimenting said relatively hingedly attached to substantially the rearmost thick swept leading edge of said main wing panel and extremity of each said nacelle so constructed and 30 thus blending in as an integral portion of said wing.
arranged as to direct thrust; 5. The aircraft of claim 1 and including means for means for selectively positioning said jet exit nozzles angularly positioning said wing apex segments in the such that their angle of declination increases the deployed position such that the angle of incidence of positive lift component of the thrust vector during said wing apex segments is selectively variable between -110" and +210".
reductions in flight speed from supersonic to sub- 35