Aircraft with improved aerodynamic performance

• US 9,284,046 B2
• Filed: 05/30/2011
• Issued: 03/15/2016
• Est. Priority Date: 02/14/2011
• Status: Active Grant

• Current Assignee: Alenia Aermacchi SPA (Leonardo S.p.A.)
• Original Assignee: Alenia Aermacchi SPA (Leonardo S.p.A.)
• Inventors: Lucchesini, Massimo, Merlo, Emanuele
• Primary Examiner(s): Benedik, Justin
• Application Number:
  US13/985,522
• Publication Number:
  US 20140070056A1
• Time in Patent Office: 1,751 Days
• Field of Search: 2441991-1994, 244/88
• US Class Current: 1/1
• CPC Class Codes: B64C 1/0009 Aerodynamic aspects
• CPC Class Codes: B64C 1/1476 Canopies; Windscreens or similar transparent elements
• CPC Class Codes: B64C 23/06 by generating vortices
• CPC Class Codes: B64D 33/02 of combustion air intakes air intakes for gas-turbine plants or jet-propulsion plants per se F02C7/04; air intakes for combustion engines in general F02M35/00
• CPC Class Codes: B64D 7/00 Arrangements of military equipment, e.g. armaments, armament accessories, or military shielding, in aircraft; Adaptations of armament mountings for aircraft dropping bombs or the like B64D1/00; armaments or mountings therefor per se F41
• CPC Class Codes: Y02T 50/10 Drag reduction

Abstract

An aircraft (10) with improved aerodynamic performances is adapted to keep the directional stability and a very good aerodynamic behavior at medium-high incidence. The aircraft (10) includes a fuselage (12) to which shaped wings (18, 20) are associated, and a nose (52). The aircraft (10) also includes a vortex control device (72) of the extension of the leading edge of the wing at the root (LERX), shaped in order to symmetrize the bursting of the vortices generated by such LERX with a medium-high incidence. Said aircraft comprises removable equipment with at least one dissipation device of incident radar waves, on at least one hot portion of the aircraft.

Claims

1. An aircraft with improved aerodynamic performances, for maintaining direction stability and optimal aerodynamic behaviour with a medium-high incidence;

said aircraft comprising a fuselage to which wings are associated, at least one air intake and a nose with a tapered section, and at least one engine;

wherein said aircraft comprises a control device of the vortex of a leading edge extension of the wing leading edge root extension, in which the ratio between the surface of one leading edge extension and a height of a corresponding control device is 2.35 m with a variable tolerance in a range from 100% and −

50% of the ratio, comprising between 1.175 m and 4.70 m, said control device of the vortex generated by the edge, cooperates with a tail, obtained by coupling of a vertical tail with the wings whose leading edges penetrate trailing edges of each wing;

an equipment comprising at least one dissipating device of incident radar waves which is removably applied on at least one hot portion of the aircraft;

the at least one hot portion of the aircraft comprising;

a piloting cabin or cockpit having at least one transparent portion;

a fuselage frame;

a plurality of leading edges of components, the components comprising wings, tail veils and air intakes of the at least one engine;

at least one engine face;

wherein to reduce radar marking from the at least one engine face, the equipment comprises at least one grid having an inner structure with a plurality of apertures, and a support structure having a plurality of rings securing said grid to the aircraft;

each of the apertures comprises an internal surface coated with radar absorbing material adapted to absorb electromagnetic waves at high frequency;

said grid is adapted to permit entry of air flow towards the at least one engine and reduce radar visibility of the at least one engine face of the aircraft.

2. The aircraft according to claim 1, wherein said nose, with a low extension, has a profile with a variable geometry starting from a tip up to a connecting corner of said nose with an apex of said leading edge root extension, said profile having, starting from said tip, a substantially circular section and a section with an oval and domed geometric shape.

3. The aircraft according to claim 1, wherein said decoupling of the horizontal and vertical tail is obtained by a vertical stabilizer with a trapezium shape and coupled with the wing wherein the leading edges penetrate the trailing edges of each wing.

4. The aircraft according to claim 3, wherein said decoupling of the tail is obtained by a horizontal empennage having a trapeze shape, with symmetric and asymmetric deflection, said horizontal stabilizer having a trapezium shape, with the symmetric and asymmetric deflection, said horizontal stabilizer having a hinge axis, which is inclined with respect to a transversal axis of the aircraft.

5. The aircraft according to claim 1, wherein said air intake does not have a spacer of limit layer or diverter on the upper side of the intake.

6. The aircraft according to claim 1, wherein said air intake has a medium radius at the leading edge of an inner lip equal to 7 mm, wherein a medium radius of a lower lip is equal to 17.5 mm and a medium radius of an outer radius is equal to 14 mm, the capture area of said air intake is equal approximately to 0.322 m², the throat area of the air intake is approximately equal to 0.257 m² and the air inlet to the engine is approximately equal to 0.273 m².

7. The aircraft according to claim 1, wherein each wing of the aircraft is shaped as a trapezium and has at least a saw-tooth area in at least one portion of the wingspan, said wing also providing an leading edge with a radius with a triangular profile.

8. The aircraft according to claim 1, wherein each wing of the aircraft is provided with a profile with variable bending, both at the leading edge and of the trailing edge, near at least one flap, for producing a reduction of the bending which alleviates effects of compressibility.