WING ASSEMBLY FOR AN AIRCRAFT

Abstract

The present invention relates to a wing assembly (10) for an aircraft with a fuselage and at least one pair of wings, the wing assembly (10) defining a direction of flow (F) with respect to which the wing assembly (10) is configured to create lift for the aircraft, comprising a main section (12), which is configured to be mounted to the fuselage in a fixed manner so as to extend from the fuselage in an extension direction of the wing; and a plurality of flap sections (14) each with a body part (16), which are mounted to the main section (12) in a pivotable manner so as to be individually pivotable around a pivot axis (A) by means of a pivoting means (18) over a range of angular orientations including a horizontal orientation in which the body part (16) of the flap section (14) is substantially aligned with the main section (12) to form an elongate and substantially continuous cross-section; and a vertical orientation in which the flap section (14) is angled downwards with respect to the main section (12). The invention further relates to an aircraft equipped with at least one pair of such wing assemblies.

Claims

1. A wing assembly for an aircraft with a fuselage and at least one pair of wings, the wing assembly defining a direction of flow (F) with respect to which the wing assembly is configured to create lift for the aircraft, comprising: a main section, which is configured to be mounted to the fuselage in a fixed manner so as to extend from the fuselage in an extension direction (W) of the wing; and a plurality of flap sections each with a body part, which are mounted to the main section in a pivotable manner so as to be individually pivotable around a pivot axis (A) by means of a pivoting means over a range of angular orientations including: a horizontal orientation in which the body part of the flap section is substantially aligned with the main section to form an elongate and substantially continuous cross-section; and a vertical orientation in which the flap section is angled downwards with respect to the main section; wherein the flap sections each comprises a single ducted fan engine with a cowling, an air inlet and an air outlet which in operation is configured to produce thrust in a predetermined thrust value range; and wherein each ducted fan engine is formed in an integral manner with the body part of its corresponding flap section such that said body part constitutes a lower section of the cowling of the at least one ducted fan engine.

2. A wing assembly for an aircraft with a fuselage and at least one pair of wings, the wing assembly defining a direction of flow (F) with respect to which the wing assembly is configured to create lift for the aircraft, comprising: a main section, which is configured to be mounted to the fuselage in a fixed manner so as to extend from the fuselage in an extension direction (W) of the wing; at least one flap section with a body part, which is mounted to the main section in a pivotable manner so as to be pivotable around a pivot axis (A) by means of a pivoting means over a range of angular orientations including: a horizontal orientation in which the body part of the flap section is substantially aligned with the main section to form an elongate and substantially continuous cross-section; and a vertical orientation in which the flap section is angled downwards with respect to the main section; wherein the at least one flap section comprises at least one ducted fan engine with a cowling, an air inlet and an air outlet which in operation is configured to produce thrust in a predetermined thrust value range; wherein the at least one ducted fan engine is formed in an integral manner with the body part of the flap section such that said body part constitutes a lower section of the cowling of the at least one ducted fan engine; wherein operational conditions of the wing assembly include the current angular orientation of the at least one flap section and the thrust currently produced by the at least one ducted fan engine; and wherein the main section and the at least one flap section are configured such that at least in a range of operational conditions of the wing assembly, the at least one flap section produces at least about 40% of the lift of the wing assembly.

3. The wing assembly according to claim 2, wherein a plurality of flap sections are provided which are each individually pivotable and each comprise a single ducted fan engine.

4. The wing assembly according to claim 1, wherein the direction of the pivot axis (A) of the at least one flap section substantially corresponds to the extension direction (W) of the wing.

5. The wing assembly according to claim 1, wherein an upper section of the cowling and/or side panels of the at least one ducted fan engine with the at least one flap section in horizontal orientation is formed with a cross section in the direction of flow (F) of the wing assembly which produces lift during operation of the engine.

6. The wing assembly according to claim 5, wherein the upper section of the cowling in a cross section in the direction of flow (F) of the wing assembly is formed with a primarily convex curvature, comprising one half of a cambered airfoil profile.

7. The wing assembly according to claim 1, wherein a radius (R23) of a leading edge nose of an upper section of the cowling normalized by its chord line length (CL) is between 1.8% and 5%, and/or the chord line length (CL) is between 600 mm to 900 mm.

8. The wing assembly according to claim 1, wherein in a plan view of the wing assembly with the at least one flap section in horizontal orientation, the at least one flap section forms at least about 40% of the total lifting surface.

9. An aircraft, comprising a fuselage, at least one pair of wing assemblies according to claim 1, and a flight control unit for controlling the angular orientations of the flap sections and the thrust output of the ducted fan engines.

10. The aircraft according to claim 9, comprising at least two pairs of wing assemblies, wherein the main section and the at least one flap section of the at least one pair of wings assemblies are configured such that at least in a range of operational conditions of the wing assembly, the flap sections of said pair of wing assemblies produce at least about 40% of the total lift of all the wings of the aircraft.

11. The aircraft according to claim 9, comprising two pairs of wing assemblies with different wingspans, wherein preferably in a horizontal flight direction of the aircraft the pair of wings with lower wingspan is mounted in front of the other pair of wings.

12. The aircraft according to claim 9, wherein the flap sections of a main pair of wings comprise between 30 and 50% of the total lifting surface of said main wings, wherein the flap sections of a pair of canard wings comprise between 50% and 70% of the total lifting surface of said canard wings, and/or wherein, under normal, trimmed cruise conditions of the aircraft, said flap sections of the main wings contribute between about 45 and 60% of the total lift of the main wings, and/or the flap sections of the canard wings contribute between 65 and 85% of the total lift of the canard wings (10b).

Description

[0022] Further features and advantages of the present invention will become even clearer from the following description of embodiments thereof, when taken together with the accompanying drawings, which show in particular:

[0023] FIG. 1 a cross-section view of a wing assembly according to the present invention;

[0024] FIG. 2 an isometric view of a single integrated flap unit of a wing assembly according to the invention;

[0025] FIG. 3 a front view of three such integrated flap units;

[0026] FIG. 4 a plan view of an aircraft according to the invention with two pairs of wings;

[0027] FIG. 5 a front view of a wing assembly with a plurality of flap units in different angular orientations; and

[0028] FIG. 6 a schematic cross-section of the upper cowling of the ducted fan engine of FIG. 1.

[0029] In FIG. 1, a wing assembly according to the present invention is shown in a cross-section view and generally denoted with reference numeral 10. Said wing assembly comprises a main section 12, which is configured to be mounted to the fuselage of an aircraft in a fixed manner so as to extend from the fuselage in an extension direction W of the wing assembly 10, which is for example shown in FIG. 4. The wing assembly 10 defines a direction of flow F with respect to which it is configured to create lift for the aircraft in horizontal flight.

[0030] Furthermore, the wing assembly 10 comprises a flap section 14 with a body part 16, which is mounted to the main section 12 of the wing assembly 10 in a pivotable manner so as to be pivotable around a pivot axis A by means of a pivoting means 18, which is shown only schematically in FIG. 1 and may for example be embodied by a servo motor.

[0031] In FIG. 1, the flap section 14 is shown in a horizontal orientation, in which its body part 16 is substantially aligned with the main section 12 of the wing assembly 10 in order to form an elongate and substantially continuous cross-section. The flap section 14 may be pivotable around the pivot axis A over a range of for example 90° such that it can be angled downwards into a vertical orientation, in which the main section 12 and the body part 16 of the flap section 14 are substantially perpendicular to one another.

[0032] The flap section 14 further comprises a ducted fan engine 20 with a cowling 22, a leading edge nose 23, an air inlet 24, an air outlet 26, a rotatable rotor 28 and a fixed stator 30 which during operation by means of rotation of the rotor 28 produces thrust along the thrust axis T.

[0033] It shall further be pointed out that while the ducted fan engine 20 is formed in an integral manner with the body part 16 of the flap section 14 such that said body part 16 constitutes a lower section of the cowling 22 of the ducted fan 20, the upper section 22a of the cowling is also formed with such a cross-section in the direction of flow F of the wing assembly 10 that it also contributes to the lift provided by the flap section 14.

[0034] By angling the flap section 14 with respect to the main section 12 around the pivot axis A, the flap section 14 may act as a control surface of the wing assembly 10, while simultaneously the thrust vector T is rotated and the lift provided by the flap section 14 is varied as well. Thus, by integrating the pivotable flap section 14 with the ducted fan engine 20, said flap section 14 acts as an aerodynamic control surface at the same time as being able to vector thrust, thus providing two degrees of freedom within a single unit. With the flap section 14 furthermore contributing a substantial percentage of the lifting surface of the wing assembly 10, vastly improved maneuverability and higher flight speed is made possible compared to conventional designs.

[0035] Consequently, the flap section 14 produces a significant proportion of the total aircraft lift in addition to providing thrust magnitude and thrust vectoring that can be altered individually. Said flap section 14 is thus utilized in all flight phases to reduce thrust demand on the engine at low flight speeds or to allow payloads to be increased. As can further be seen from FIGS. 2 and 3 discussed below, the design of air inlet 24 of the ducted fan engine 20 together with the geometrical properties of the remaining components of the flap section 14 allows for clean inlet conditions at all flap section angles.

[0036] In said FIGS. 2 and 3, a single flap section 14 with an integrated ducted fan engine 20 and three such flap sections 14 are shown in an isometric view and in a front view, respectively. It can be seen that each of the flap sections 14 carries only a single ducted fan engine 20, while in other modifications of the shown embodiment, multiple ducted fan engines might be integrated in a single flap section. It can furthermore be seen from FIGS. 2 and 3 how the cowling 22 of the ducted fan engine 20 is shaped in its upper section 22a as well as in the section of the side panels 22b of the ducted fan engine 20 in an aerodynamic manner with a cross-section, which will also contribute to producing lift with the flap section 14 during operation of the engine 20.

[0037] Furthermore, in FIG. 4, an aircraft 100 with a fuselage 102 and two pairs of wings 10a and 10b is shown in a plan view, wherein each of the wings 10a and 10b is equipped with flap sections as discussed above, and wherein the first pair of wings 10a serve as main wings, while the second pair of wings 10b with a shorter wingspan serve as canard wings located in front of the main wings 10a.

[0038] Therein, the overall planform of the main wings 10a is chosen such that the flap sections contribute to about 35% of the overall main wing planform as indicated by boxes 104, whereas the flap sections of the canard wings 10b contribute to about 61% of the total planform surface of the canard wings 10b as indicated by boxes 106. The respective wing planforms are defined to extend toward the centerline C of the aircraft 100.

[0039] Due to the additional lift contributed by the specific design of the flap sections 14 provided to the wings 10a and 10b as discussed above, in nominal, trimmed cruise condition of the aircraft 100, the flap sections of the main wings 10a will contribute about 49% of the total lift of said main wings 10a, while the flap sections of the canard wings 10b will contribute about 77% of the total lift produced by the canard wings 10b. Thus, the flap sections of the main wings 10a and canard wings 10b combined will produce more than 50% of the overall lift of the aircraft 100 under said conditions.

[0040] Additionally, in FIG. 5, one of the main wings 10a is shown in a front view with its plurality of flap units 14 all in different angular orientations, in order to demonstrate their ability to independently pivot over a range of angular orientations.

[0041] Lastly, in FIG. 6, a schematic cross-section in the direction of flow F of the upper section 22a of the cowling 22 of the ducted fan engine 20 of FIG. 1 is shown, which provides for minimum inlet distortion of air sucked into the engine 20 in hovering configuration as well as maximum lift in cruise configuration of the respective flap unit 14. In particular, the upper section 22a of the cowling 22 is formed with a primarily convex curvature as one half of a cambered airfoil profile with camber line CA, wherein the dashed line in FIG. 6 represents the theoretical lower half of said profile.

[0042] Furthermore, the radius R23 of the leading edge nose 23 of the upper section 22a of the cowling 22 normalized by its chord line length CL is between 1.8% and 5%, preferably about 2%, while typically the chord line length CL of such engines 20 ranges between 600 mm to 900 mm and may in particular be about 780 mm.