frontal area high-lift configuration

Abstract

The present application relates to a kind of front edge lift-increasing layout for aircraft, including the wing front edge (2) being arranged in the fuselage (1) both sides of aircraft, wing front edge (2) is interrupted by the engine suspension (5) equipped with power source, wing front edge (2) is at least one of fixed wing front edge (8), inner slit wing (3) being arranged in the inside of engine suspension (5) and outer slit wing (6) being arranged in the outside of engine suspension (5).When aircraft is in high-speed cruising state, inner slit wing (3) and outer slit wing (6) are retracted and form discontinuous wing front edge (2) with fixed wing front edge (8).When aircraft is in low-speed lift-increasing state, inner slit wing (3) and outer slit wing (6) are unfolded to expose fixed wing front edge (8), and fixed wing front edge (8) constitutes continuous wing front edge (2).The front edge lift-increasing layout can reduce airflow separation inside wing in a simple and economical way, and improve the aerodynamic characteristics of aircraft.

Description

Technical Field

[0001] The present invention relates to a leading-edge lift enhancement configuration, and more specifically, to a leading-edge lift enhancement configuration for an aircraft. Background Technology

[0002] The aerodynamic characteristics of an aircraft determine its safety, economy, comfort, and environmental friendliness. Among these, the wing, as the main component that contributes lift to the aircraft, plays a crucial role in the overall aerodynamic characteristics of the aircraft.

[0003] An aircraft wing consists of a basic wing with high-speed cruise characteristics and lift-enhancing components with low-speed takeoff and landing characteristics. The basic wing, also known as a fixed wing, is an important component of an aircraft. Lift-enhancing components typically include leading-edge flaps, leading-edge slats, and trailing-edge flaps. They improve the aerodynamic characteristics of the basic wing, enabling the aircraft to generate sufficient lift at low speeds during takeoff and landing. Therefore, their layout plays a crucial role in wing design.

[0004] The basic wing and the lift-enhancing components together constitute the overall wing shape. For wing-mounted aircraft, the wing shape of high-speed cruise aircraft, whether Boeing or Airbus, is currently continuous. That is, in the high-speed cruise configuration, when the lift-enhancing components are retracted, the overall wing shape formed by the lift-enhancing components and the fixed wing is continuous.

[0005] The propulsion system installed on an aircraft is generally referred to as the power plant, which includes the engine itself and its matching nacelle assembly. The nacelle assembly includes air intakes, fan cowlings, thrust reversers, and exhaust nozzles. These nacelle assemblies are mounted to the aircraft fuselage along with the engine itself. The fan cowling and thrust reversers are typically hinged to engine mounts located under the engine wings. Due to the presence of these engine mounts and winglets at the wingtips, the lift-enhancing components themselves are usually discontinuous. That is, in high-speed cruise configurations, if a continuous wing leading edge is required, the continuity of the fixed wing leading edge cannot be guaranteed.

[0006] Please see Figure 1 This illustrates the layout of a conventional wing leading edge in a cruise configuration. For example... Figure 1 As shown, from the fuselage 1, the aircraft is arranged sequentially from near to far with an inner slat 3, an engine mount 5, an outer slat 6, and a winglet 7. The engine is mounted under the wing via the engine mount 5. In the cruise configuration, the inner slat 3 and the outer slat 6 are retracted. Figure 1 As shown in the dashed box, the fixed wing leading edge 8, together with the inner slat 3 and the outer slat 6, forms the wing leading edge 2. In the cruise configuration, the wing leading edge 2 is continuous.

[0007] Although the leading edge 2 of the wing is continuous in the cruise configuration, the aerodynamic effects are poor in the areas where the wing root meets the fuselage bulge and where the wing meets the engine pylon 5. The latter area, in particular, is near the junction of the pylon and the wing. The compact structure between the engine, pylon, and wing in this area leads to airflow congestion, which, combined with unfavorable lateral flow, produces harmful aerodynamic effects.

[0008] Please see Figure 2 This illustrates the layout of a conventional wing leading edge in a lift-enhancing configuration. For example... Figure 2 As shown, in the lift-enhancing configuration, the inner and outer slats 3 and 6 are deployed to expose the leading edge 8 of the fixed wing. At this point, the leading edge 8 of the fixed wing exhibits discontinuity at the wing root, engine mount 5, and the transition between the wing and winglets. This discontinuity in the leading edge 8 adversely affects the airflow over the inner upper surface of the wing, leading to further airflow separation in the upper wing area corresponding to the engine mount 5, and consequently reducing the lift coefficient and impacting the aerodynamic characteristics of the aircraft.

[0009] To eliminate the discontinuities caused by engine mounts, current methods typically employ inner-side modification of the mounts or partial Kruger flaps to achieve continuity of the leading-edge lift-enhancing components and reduce the impact of engine mounts on aerodynamic characteristics. However, in practical applications, the improvement effect is not significant.

[0010] Chinese invention patent application CN10100222A, filed by Airbus Spanish Operations S.A. on November 2, 2011, discloses a lifting surface for an aircraft to increase the generated lift. The lifting surface includes a leading edge and a notch located in the leading edge. The notch includes two walls adapted to be parallel to the incident flow direction of the lifting surface during aircraft flight, and a third wall adapted to face the incident flow towards the lifting surface. The lifting surface also includes a retractable covering element. The notch and the retractable covering element are configured such that when the retractable covering element is not covering the notch, the notch is exposed to the incident flow, thereby generating vortices that increase the lift of the lifting surface and delay stall.

[0011] In the high-speed cruise configuration, the lifting surface disclosed in the aforementioned patent application has a cover element that covers the notch, forming a continuous lifting surface shape. In the low-speed configuration, the cover element no longer covers the notch, leaving it exposed to increase lift and delay stall. However, this type of lifting surface requires notches and retractable cover elements, increasing the complexity, weight, and cost compared to traditional lifting surfaces, and still fails to meet the requirements of economy and cost.

[0012] Therefore, a new leading-edge lift enhancement layout needs to be designed, which can reduce airflow separation on the inner side of the wing in a simple and economical way and improve the aerodynamic characteristics of the aircraft. Summary of the Invention

[0013] The purpose of this invention is to provide a leading-edge lift enhancement configuration for aircraft that can reduce airflow separation on the inboard side of the wing in a simple and economical manner, thereby improving the aerodynamic characteristics of the aircraft.

[0014] This invention discloses a leading-edge lift enhancement layout for an aircraft, including wing leading edges disposed on both sides of the aircraft fuselage. The wing leading edges are interrupted by engine mounts equipped with power sources. The wing leading edges are composed of at least one of a fixed wing leading edge, an inner slat disposed inside the engine mount, and an outer slat disposed outside the engine mount. When the aircraft is in a high-speed cruise state, the inner and outer slats are retracted and together with the fixed wing leading edge form a discontinuous wing leading edge. When the aircraft is in a low-speed lift enhancement state, the inner and outer slats are deployed to expose the fixed wing leading edge, and the fixed wing leading edge constitutes a continuous wing leading edge.

[0015] The term "fixed-wing leading edge" refers to the leading edge formed on the upper surface of a fixed wing, while the term "wing leading edge" is composed of at least one of the fixed-wing leading edge, inner slat, and outer slat. In a high-speed cruise configuration, the wing leading edge is composed of the fixed-wing leading edge, inner slat, and outer slat. In a low-speed lift-enhancing configuration, the wing leading edge is composed only of the fixed-wing leading edge.

[0016] In a preferred embodiment, when the aircraft is in high-speed cruise mode, the inner and outer slats can be retracted and form at least one notch on the leading edge of the fixed wing.

[0017] For example, at least one notch may include a first notch located in the engine mounting area.

[0018] Preferably, the first notch can be formed by the outer end face of the inner slat, the leading edge of the fixed wing, and the inner end face of the outer slat.

[0019] For example, at least one notch may also include a second notch located in the wing root region of the aircraft.

[0020] Preferably, the second notch can be formed by the fuselage bulge, the leading edge of the fixed wing, and the inner end face of the inner slat.

[0021] In a preferred embodiment, the aircraft may be designed with winglets at the far end of the leading edge of the wing.

[0022] In this embodiment, at least one notch may also include a third notch located in the wingtip region of the aircraft.

[0023] Preferably, the third notch can be formed by the outer end faces of the winglet and the outer slat.

[0024] In the above embodiments, the maximum height dimension of at least one notch is less than or equal to 0.5% of the local chord length of the aircraft. This is also the criterion for distinguishing between "continuous" and "discontinuous". When the maximum height dimension of the notch is greater than the local chord length of the aircraft, the wing leading edge should be considered discontinuous.

[0025] The leading edge lifting configuration according to the present invention provides the following advantages:

[0026] First, the leading-edge lift configuration according to the present invention can reduce airflow separation on the wing surface, delay stall angle of attack in low-speed configurations, and at the same time, does not increase cruise drag, thus improving the aerodynamic characteristics of the aircraft.

[0027] The beneficial effects of the aforementioned leading-edge lifting configuration in low-speed configurations include:

[0028] (i) Increase the maximum lift coefficient;

[0029] (ii) Delay stall angle of attack and improve stall characteristics;

[0030] (iii) Increase the lift-to-drag ratio.

[0031] The beneficial effects of the aforementioned leading-edge lift configuration in high-speed configurations include:

[0032] (i) Lift is slightly increased near the angle of attack used in the cruise configuration;

[0033] (ii) The resistance is reduced, achieving a drag reduction effect;

[0034] (iii) Improved torque characteristics.

[0035] Second, compared with the covering elements used in the prior art, the leading edge lifting layout of the present invention achieves a simpler continuous surface structure and has a lower manufacturing cost by removing the components (i.e., slats) where the two end faces forming the notch are located.

[0036] Third, the present invention utilizes the deployment of slats to achieve the formation of a continuous shape (i.e., the leading edge of a fixed wing), and utilizes the retraction of slats to achieve the formation of a notch and a discontinuity at the leading edge of the wing. Attached Figure Description

[0037] To further illustrate the technical effects of the leading-edge lift enhancement configuration for aircraft according to the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, wherein:

[0038] Figure 1 This is a schematic diagram of the layout of the leading edge of a traditional wing in a cruise configuration;

[0039] Figure 2 This is a schematic diagram of the layout of the leading edge of a traditional wing in a lift-enhancing configuration;

[0040] Figure 3A This is a top view of a wing having the leading edge layout of the present invention in a cruise configuration;

[0041] Figure 3B Is with Figure 3A A similar diagram shows the position of the slats in the retracted state;

[0042] Figure 4A This is a top view of a wing having the leading edge layout of the present invention in a lift-enhancing configuration;

[0043] Figure 4B Is with Figure 2 Similar schematic diagrams show the difference between the fixed wing leading edge of the wing with the wing leading edge layout of the present invention and the prior art in terms of continuity;

[0044] Figure 5A It is a 3D streamline diagram of a wing with a conventional leading edge in a lift-enhancing configuration;

[0045] Figure 5B It is a 3D streamline diagram of a wing having the leading edge layout of the present invention in a lift-enhancing configuration;

[0046] Figure 6 This is a comparison table of lift curves for wings with conventional wing leading edges and wings with the wing leading edge layout of the present invention in lift-enhancing configurations.

[0047] Figure 7 This is a comparison table of lift-to-drag ratio curves for wings with conventional wing leading edges and wings with the wing leading edge layout of the present invention in lift-enhancing configurations.

[0048] Figure 8 This is a comparison table of lift curves in cruise configurations for wings with conventional wing leading edges and wings with the wing leading edge layout of the present invention.

[0049] Figure 9 This is a comparison table of drag curves in cruise configurations for wings with conventional leading edges and wings with the leading edge configuration of this invention; and

[0050] Figure 10 This is a comparison table of moment curves in cruise configurations for wings with conventional wing leading edges and wings with the wing leading edge layout of the present invention.

[0051] Figure Labels

[0052] 1. Fuselage

[0053] 2. Leading edge of the wing

[0054] 3. Inner slats

[0055] 4 Engines

[0056] 5. Engine suspension

[0057] 6. Outer slats

[0058] 7. Winglets

[0059] 8. Leading edge of fixed wing

[0060] 9a First notch

[0061] 9b Second notch

[0062] 9c Third notch Detailed Implementation

[0063] The specific structure and technical effects of the leading-edge lift enhancement layout for aircraft according to the present invention will be described below with reference to the accompanying drawings.

[0064] It should be understood that the embodiments described in this specification cover only a portion of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments described in this specification without inventive effort are within the scope of protection of this invention.

[0065] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings are intended to cover a non-exclusive inclusion. The singular forms "a," "described," and "the" as used in the embodiments of the invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0066] Based on the same orientational understanding, in the description of this invention, the terms "length", "stretching", "chordal", "inner (side)", "outer (side)", "far end", "proximal end", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0067] Figure 3A This is a top view of a wing having the leading edge layout of the present invention in a cruise configuration. Figure 3B This indicates the positions of the inner and outer slats when they are in the retracted state.

[0068] like Figure 3A and3B As shown, the leading-edge lift enhancement configuration for an aircraft according to the present invention includes wing leading edges 2 disposed on both sides of the fuselage 1 of the aircraft, the wing leading edges 2 being interrupted by engine mounts 5 equipped with power sources such as engines 4. The wing leading edge 2 is composed of at least one of a fixed-wing leading edge 8, an inner slat 3 disposed inside the engine mount 5, and an outer slat 6 disposed outside the engine mount 5. When the aircraft is in high-speed cruise mode, the inner slat 3 and the outer slat 6 are retracted and together with the fixed-wing leading edge 8 form a discontinuous wing leading edge 2; when the aircraft is in low-speed lift enhancement mode, the inner slat 3 and the outer slat 6 are deployed to expose the fixed-wing leading edge 8, which forms a continuous wing leading edge 2. In other words, in the low-speed lift enhancement configuration, the fixed-wing leading edge 8 is the wing leading edge 2, and the wing leading edge 2 is continuous.

[0069] It should be understood by those skilled in the art that the term "fixed wing leading edge" refers to the leading edge extending along the span of the wing from the wing root to the winglet tip, while "continuous wing leading edge" refers to a wing leading edge 8 without any notches, chamfers, convex edges, etc., that affect the stable flow of airflow. This concept should be well known to those skilled in the art.

[0070] exist Figure 3A In the cruise configuration shown, the wing leading edge 2, formed by the retracted inner slat 3 and outer slat 6 together with the fixed wing leading edge 8, is discontinuous. Specifically, the retracted inner slat 3 and outer slat 6, together with the fixed wing leading edge 8, enclose at least one notch. In the embodiment shown in the figure, a total of three notches are formed: a first notch 9a located in the engine mount 5 area; a second notch 9b located in the wing root area of ​​the aircraft; and a third notch 9c located in the wingtip area of ​​the aircraft.

[0071] It is important to emphasize that the third notch 9c located in the wingtip region of the aircraft can only be formed if the winglet 7 is provided at the far end of the leading edge 2 of the aircraft's wing. In other words, if the aircraft is not equipped with the winglet 7, the inner slat 3 and the outer slat 6 may only form two notches 9a and 9b with the leading edge 8 of the fixed wing, which is easy for those skilled in the art to understand.

[0072] like Figure 3B As shown, the first notch 9a is located in the engine mount 5 area and is surrounded by the outer end face of the inner slat 3, the leading edge 8 of the fixed wing, and the inner end face of the outer slat 6. The second notch 9b is located in the wing root area of ​​the aircraft and is surrounded by the bulge of the fuselage 1, the leading edge 8 of the fixed wing, and the inner end face of the inner slat 3. The third notch 9c is surrounded by the winglet 7 and the outer end face of the outer slat 6. Since the winglet 7 is usually at a specific angle to the wing, the third notch generally has a stepped cross-section.

[0073] Figure 4A This is a top view of a wing with the leading edge layout of the present invention in a lift-enhancing configuration, and Figure 4B The diagram illustrates the difference in continuity between the fixed wing leading edge of the wing having the wing leading edge layout of the present invention and the prior art. It can be seen that when the aircraft is in a low-speed lift-in state, the inner slat 3 and the outer slat 6 move outward from the retracted position to the deployed position, forming a continuous wing leading edge 2 with the fixed wing leading edge 8.

[0074] Existing technologies in this field typically consider only a single lifting surface that does not interact with other components. In this case, the combination of a continuous shape of the wing leading edge 2 at high speeds and a notched shape at low speeds can produce good aerodynamic effects. However, in the technical solution of this application, the wing leading edge 2 of the wing-mounted aircraft has been improved so that the fuselage leading edge 2 connects with the fuselage bulge in the wing root region, with the mounted engine 5 in the middle region, and with the winglet 7 in the wingtip region. In this case, better aerodynamic effects are achieved.

[0075] The inventors of this application modify the leading edge layout of a traditional wing, ensuring that the fixed wing leading edge 8 remains continuous in a low-speed lift-enhancing configuration, while the wing leading edge 2 exhibits overall discontinuity in a high-speed cruise configuration, creating at least one discontinuity. Thus, in the low-speed lift-enhancing configuration, the continuity of the fixed wing leading edge 8 improves low-speed characteristics, increases the maximum lift coefficient, delays stall, and improves stall characteristics; in the high-speed cruise configuration, the multiple discontinuities of the wing leading edge 2 achieve drag reduction.

[0076] Therefore, this application, through the design of the wing leading edge layout, not only improves the problem of leading edge discontinuity in low-speed configuration, but also solves the problem of poor aerodynamic effects at the wing root, wingtip and pylon area in high-speed configuration.

[0077] Figure 5A It is a 3D streamline diagram of a wing with a conventional leading edge in a lift-enhancing configuration, while Figure 5B It is a 3D streamline diagram of a wing with the leading edge layout of the present invention in a lift-enhancing configuration.

[0078] like Figure 5A and 5B As shown, it can be clearly seen that when the inner slat 3 and the outer slat 6 are deployed, the airflow around the wing with the leading edge layout of the present invention is significantly smoother than that of the wing with the conventional leading edge, which indicates that the stall characteristics are significantly improved.

[0079] Figure 6This table compares the lift curves of a wing with a conventional leading edge and a wing with the leading edge configuration of the present invention in lift-enhanced configurations. The solid lines represent the lift curves of the comparative example, while the dashed lines represent the lift curves of the present invention. It can be seen that the maximum point of the lift curve of the present invention is higher in the lift-enhanced configuration, indicating an improvement in the maximum lift coefficient. Furthermore, the present invention also improves the stall angle of attack, delays stall, and improves stall characteristics.

[0080] Figure 7 This table compares the lift-to-drag ratio curves of a wing with a conventional leading edge and a wing with the leading edge configuration of the present invention in lift-enhanced configurations. The solid line represents the lift-to-drag ratio curve of the comparative example, while the dashed line represents the lift-to-drag ratio curve of the present invention. It can be seen that the lift-to-drag ratio curve of the present invention is improved at different lift levels in the lift-enhanced configuration.

[0081] Figure 8 This table compares the lift curves of a wing with a conventional leading edge and a wing with the leading edge configuration of the present invention in a cruise configuration. The solid lines represent the lift curves of the comparative example, while the dashed lines represent the lift curves of the present invention. It can be seen that the lift curve of the present invention provides a slight increase in lift near the angle of attack used in the cruise configuration.

[0082] Figure 9 This table compares the drag curves of a wing with a conventional leading edge and a wing with the leading edge configuration of this invention in cruise configurations. The solid lines represent the drag curves of the comparative example, while the dashed lines represent the drag curves of this invention. It can be seen that the drag curves of this invention decrease in cruise configurations, achieving a drag reduction effect.

[0083] Figure 10 This table compares the moment curves of a wing with a conventional leading edge and a wing with the leading edge configuration of this invention in cruise configuration. The solid line represents the moment curve of the comparative example, while the dashed line represents the moment curve of this invention. It can be seen that the moment curve of this invention improves the upward pitching phenomenon in cruise configuration to a smooth downward deflection, thus improving the moment characteristics, making the maximum usable angle of attack unrestricted, and increasing the maximum usable lift coefficient in cruise configuration.

[0084] While the foregoing description of a leading-edge lift enhancement layout for an aircraft has been illustrated with reference to preferred embodiments and accompanying drawings, those skilled in the art should recognize that the examples described are merely illustrative and should not be construed as limiting the invention. Therefore, modifications and variations can be made to the invention within the spirit and scope of the claims, and all such modifications and variations will fall within the scope claimed by the claims.

Claims

1. A leading-edge lift enhancement configuration for an aircraft, comprising wing leading edges (2) disposed on both sides of the fuselage (1) of the aircraft, the wing leading edges (2) being interrupted by engine mounts (5) equipped with power sources, the wing leading edges (2) being composed of at least one of a fixed wing leading edge (8), an inner slat (3) disposed inside the engine mount (5), and an outer slat (6) disposed outside the engine mount (5). When the aircraft is in high-speed cruise mode, the inner slat (3) and the outer slat (6) retract and together with the leading edge (8) of the fixed wing, form a spanwise discontinuous wing leading edge (2); and When the aircraft is in a low-speed lift state, the inner slat (3) and the outer slat (6) unfold to expose the leading edge (8) of the fixed wing, which forms a spanwise continuous wing leading edge (2).

2. The leading edge augmentation layout as described in claim 1, characterized in that, When the aircraft is in high-speed cruise mode, the inner slat (3) and the outer slat (6) retract and form at least one notch on the leading edge (8) of the fixed wing.

3. The leading edge augmentation layout as described in claim 2, characterized in that, The at least one notch includes a first notch (9a) located in the engine mount (5) area.

4. The leading edge augmentation layout as described in claim 3, characterized in that, The first notch (9a) is formed by the outer end face of the inner slat (3), the leading edge (8) of the fixed wing, and the inner end face of the outer slat (6).

5. The leading edge augmentation layout as described in claim 2, characterized in that, The at least one notch also includes a second notch (9b) located at the wing root region of the aircraft.

6. The leading edge augmentation layout as described in claim 5, characterized in that, The second notch (9b) is formed by the bulge of the fuselage (1), the leading edge of the fixed wing (8), and the inner end face of the inner slat (3).

7. The leading edge augmentation layout as described in claim 2, characterized in that, The aircraft is provided with winglets (7) at the far end of the leading edge (2) of the wing.

8. The leading edge augmentation layout as described in claim 7, characterized in that, The at least one notch also includes a third notch (9c) located in the wingtip region of the aircraft.

9. The leading edge lifting configuration as described in claim 8, characterized in that, The third notch (9c) is formed by the outer end face of the wingtip winglet (7) and the outer slat (6).

10. The leading edge lifting configuration as described in any one of claims 2 to 9, characterized in that, The maximum height dimension of the at least one notch is less than or equal to 0.5% of the local chord length of the aircraft.

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