ELECTRIC-PROPULSION AIRCRAFT COMPRISING A CENTRAL WING AND TWO ROTATABLE LATERAL WINGS

Abstract

An aircraft includes a central wing accommodating passengers and/or freight and two lateral wings that pivot on the central wing about respective axes of rotation. The various wings obey the following geometric characteristics: 0.3×Long<L.sub.arg<L.sub.ong, 0.11×L.sub.ong<H.sub.aut<0.25×L.sub.ong, E.sub.nv>1.4×L.sub.ong, wherein L.sub.arg being the distance between the two axes, L.sub.ong being the length of the central wing, H.sub.aut being the height of the central wing, E.sub.nv being the wingspan of the aircraft. The axes of rotation are inclined by an angle relative to the vertical axis of the aircraft such that the lateral pivot from rear to front and vice versa so as to come closer to, or deploy on either side from, the fuselage.

Claims

1-9. (canceled)

10. An aircraft comprising a main fuselage composed of a central wing accommodating at least one of passengers and freight, two lateral wings pivoting on the central wing about respective axes of rotation, the wings obeying the following geometric characteristics:
0.3×L.sub.ong<L.sub.arg<L.sub.ong;
0.11×L.sub.ong<H.sub.aut<0.25×L.sub.ong;
E.sub.nv>1.4×L.sub.ong; where: L.sub.arg being a distance between the two axes of rotation of the two lateral wings; L.sub.ong being a length of the central wing; H.sub.aut being a height of the central wing; E.sub.nv being a wingspan of the aircraft; and wherein the two axes of rotation of the lateral wings are inclined by an angle β relative to a vertical axis of the aircraft, such that the two lateral wings pivot from rear to front and vice versa so as to come closer to, or be deployed on either side from, the main fuselage.

11. The aircraft of claim 10, wherein 10°<β<50°.

12. The aircraft of claim 10, wherein each of the two lateral wings comprise at least one aerodynamic control surface.

13. The aircraft of claim 10, wherein the two lateral wings pivot about the respective axes of rotation between a first extreme deployed flight position and a second extreme folded storage position of the aircraft, an amplitude of an angle Ω between the two extreme positions being 70°.

14. The aircraft of claim 10, wherein the two lateral wings pivot about the respective axes of rotation between a first extreme deployed flight position and a second deployed intermediate take-off position, an amplitude of an angle Ω between the two positions being 40°.

15. The aircraft of claim 10, wherein the two lateral wings pivot about the respective axes of rotation between a first extreme deployed flight position and a landing position, an amplitude of an angle Ω between the two positions being 40°.

16. The aircraft of claim 10, further comprising at least one pylon above the central wing supporting at least one of an electric propulsion and a thermal propulsion, said at least one pylon integrating at least one aerodynamic control surface.

17. The aircraft of claim 10, further comprising at least two hydrofoils below the central wing, said at least two hydrofoils being retractable in the central wing.

18. The aircraft of claim 10, further comprising at least one door at least at one of rear and front of the central wing.

19. The aircraft of claim 10, further comprising at least one cockpit on top of the central wing and located at a height of the two lateral wings.

20. The aircraft of claim 10, further comprising an emergency parachute inside the central wing.

Description

BRIEF DESCRIPTION OF FIGURES

[0032] Other advantages, aims and features of the present invention emerge from the following description made, for explanatory and not limiting purposes, with reference to the appended drawings, in which:

[0033] FIG. 1 is a front-top perspective view of ¾ of an aircraft in accordance with the present invention, with lateral wings in the level flight position and the representation of an X, Y, Z coordinate system,

[0034] FIG. 2 is a view similar to FIG. 1 in which the wings are partially folded forwards, in the flight position during the landing and/or take-off phase of the aircraft,

[0035] FIG. 3 is a view similar to FIG. 1 in which the wings are completely folded forwards, in the storage position,

[0036] FIG. 4 is a top view of the aircraft of FIG. 1,

[0037] FIG. 5 is a side view of the aircraft of FIG. 4, with extended foil-type fins,

[0038] FIG. 6 is a front view of the aircraft of FIGS. 5, and

[0039] FIG. 7 is a detail view of a variant of a pylon of the aircraft of FIGS. 1 to 6.

DESCRIPTION OF EMBODIMENTS

[0040] FIGS. 1 to 7 represent an aircraft 100 in accordance with the present invention, preferably with electric or hybrid propulsion.

[0041] This aircraft 100 includes a central wing 1, forming a fuselage for the transport of passengers and/or freight, and two lateral wings 2 and 2′. These wings can pivot about respective axes of rotation 3 and 3′ to take different positions which will be described later.

[0042] The general shape of the aircraft 100, and in particular of the wings 1, 2 and 2′, is of a known type, and obeys the following geometrical considerations: [0043] L.sub.arg is the distance between the two axes of rotation 3 and 3′ of the pivoting lateral wings 2 and 2′, [0044] L.sub.ong is the length of the central wing 1, [0045] H.sub.aut is the height of the central wing 1, [0046] E.sub.nv is the wingspan of the aircraft 100,

[0047] According to the present invention, these geometric characteristics must meet the following conditions:

0.3×L.sub.ong<L.sub.arg<L.sub.ong,

0.11×L.sub.ong<H.sub.aut<0.25×L.sub.ong,

E.sub.nv>1.4×L.sub.ong.

[0048] The two axes 3 and 3′ located in transition zones 4 and 4′ between the central wing 1 and the lateral wings 2 and 2′, allow pivoting each of the lateral wings 2 and 2′. The axes 3 and 3′ are located in these zones 4 and 4′ with high thickness so as to support the lift forces generated by the lateral wings 2 and 2′ on the fuselage.

[0049] As shown in FIG. 1, the axes 3 and 3′ are inclined by an angle β relative to the vertical Z. The rotation of the lateral wings 2 and 2′ by an angle Ω about the axes 3 and 3′ leads to the following considerations: [0050] for angles of rotation −40°<Ω<+40°: a variation in flight of the relative angle of aerodynamic incidence between the lateral wings 2 and 2′ and the central wing 1 accompanied by a change in the aerodynamic thrust center along the longitudinal axis X of the aircraft; [0051] for angles of rotation Ω>70° or Ω<−70°: a storage of the lateral wings 2 and 2′ forwards or backwards, in particular on the ground or on water.

[0052] The variations, of incidences and position of the thrust center, relatively between the central wing 1 and the lateral wings 2 and 2′ allows choosing the distribution of the total lift between the lateral wings 2 and 2′ and the central wing 1, these configurations being chosen according to the different phases of flight.

[0053] At high relative angles of aerodynamic incidence of the aircraft (>10°), in particular for take-off and landing, a configuration is adopted with the lateral wings 2 and 2′ which are pivoted so as to reduce their aerodynamic incidence angle to avoid the stalling of the lateral wings 2 and 2′ and maintain the effectiveness of the roll control by the fins 5 and 5′. In this configuration, the central wing 1, of low elongation, close to the shape of a delta wing, supports a greater portion of the lift thanks to the vortices generated around it, while producing a stronger induced drag. The lift-to-drag ratio thus degraded is adapted to the landing phases.

[0054] In cruise flight, the lateral wings 2 and 2′ are fully deployed (Ω=0°), the three wings distribute the lift so as to maximize the lift-to-drag ratio, the lift distribution approaches an elliptical form.

[0055] The lateral wings 2 and 2′ are each equipped with one or more rear control surfaces 5 and 5′ ensuring the aerodynamic control of the aircraft 100.

[0056] The aircraft 100 can also take off and land on water, thanks to at least two hydrofoils 6 and 6′ located below the central wing 1. The hydrofoils 6 and 6′ are retractable in respective housings 11 provided for this purpose in the central wing 1 (see arrows R). This allows reducing the drag in flight and enables low speed maneuvers in shallow water.

[0057] The central wing 1 includes a cockpit 7 located close to the lateral wings 2 and 2′ on the longitudinal axis X. This allows controlling the whole vital elements of the aircraft 100 as well as the spacing on the ground or on water, the maneuvers in ports and airports are easier.

[0058] The aircraft 100 is also provided with one or more pylons 8. Each pylon 8 supports thermal or hybrid electric powertrains 9. These pylons 8 incorporate rear control surfaces 10 for controlling the aircraft 100 in yaw and/or in pitch and/or in roll.

[0059] The rear of the central wing 1 is equipped with one or more access door(s) 12 which can be open upwards and or downwards. These doors 12 can be maneuvered on the ground, in flight, on water.

[0060] The central wing 1 is finally equipped with one or more emergency parachutes 13 distributed in the low volumes.

[0061] It should be understood that the detailed description of the object of the invention, given only by way of illustration, does not, in any way, constitute a limitation, the technical equivalents also being included within the scope of the present invention.