A wing with enhanced flapping aerodynamic performance based on biomimetic leading-edge feathers

Abstract

This invention relates to a wing with enhanced aerodynamic performance for flapping wings based on biomimetic leading-edge feathers, belonging to the field of aircraft design and manufacturing technology. It solves the problems of high maneuverability and difficulty in variable-attitude flight of existing flapping wings, effectively improving the leading-edge flow and enhancing flapping wing flight performance. This invention improves the evolution of the incoming boundary layer by introducing biomimetic leading-edge feathers to the leading edge of a curved wing body to form directional vortex pairs; it enhances the aerodynamic performance of flapping-wing UAVs by suppressing and / or improving boundary layer separation at high angles of attack through vortex-induced downwash and momentum transfer; the biomimetic leading-edge feathers do not change the existing wing aerodynamic shape, and the hardware design is completed by adding small-scale spoiler structures to the leading edge, resulting in a simple overall structure and easy maintenance; and through free control of the feather characteristic shape, number, and angle, it serves the aerodynamic enhancement of flapping-wing UAVs under different flight conditions and performance requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aircraft design and manufacturing technology, in particular to a wing based on bionic leading edge wing feather for enhancing the aerodynamic performance of flapping wing. BACKGROUND

[0002] In nature, many animals such as birds, insects, etc. have excellent flying ability, and can fly, glide and hover in the air freely. The bionic flapping wing aircraft is a kind of aircraft that imitates the structure and flight principle of the wings of flying animals in nature, and uses flapping motion to generate lift and propulsion. It has high flexibility and maneuverability. Its research and application fields are wide, including military reconnaissance, disaster rescue, scientific research, etc. It has low noise, high efficiency and low energy consumption, and can achieve efficient flight tasks in complex environments. With the continuous development and improvement of bionics technology, bionic flapping wing is becoming an important development direction in the field of aircraft design, serving military science and technology and economic development.

[0003] However, flapping flight involves large-angle continuous flapping of the wing, during which time-varying vortex and separation flow are generated, which has an important influence on the aerodynamic performance of the wing. Among them, the generation of separation flow and the shedding of vortex cause the decrease of the lift of the flapping wing aircraft and the increase of the resistance, which brings potential harm to the safe service. In order to avoid this risk, the existing flapping wing aircraft often sacrifices the maneuverability to achieve only a single flight attitude. Therefore, the design of the aerodynamic shape of the flapping wing has certain limitations, and cannot fully display the unique high maneuverability and attitude change flight ability of the flapping wing.

[0004] In summary, in order to further improve the flight ability of the flapping wing aircraft, it is necessary to improve the existing aerodynamic performance of the wing and suppress / improve the separation flow phenomenon existing in the flapping process of the wing. SUMMARY

[0005] In view of the above problems, the present application provides a wing based on bionic leading edge wing feather for enhancing the aerodynamic performance of flapping wing, which solves the problems of poor flapping maneuverability and difficult attitude change flight, effectively suppresses and optimizes the flow separation phenomenon existing in the flapping process of the flapping wing, and improves the flapping flight performance.

[0006] The present application provides a wing based on bionic leading edge wing feather for enhancing the aerodynamic performance of flapping wing, which includes at least one bionic leading edge wing feather 1 and a curved wing body 7; the wing is the wing of a flapping wing unmanned aerial vehicle;

[0007] The curved wing body 7 includes a leading edge 2, a wing root 4, a wing tip 5 and a trailing edge 6;

[0008] Preferably, at least one bionic leading edge wing feather 1 is arranged at the leading edge 2 of the curved wing body 7, forming a convex independent structure;

[0009] Further, the outer shape structure of the bionic leading edge wing feather 1 is freely adjusted according to the performance requirements of the aircraft, including a barb-shaped leading edge wing feather, a curved leading edge wing feather, a semicircular leading edge wing feather, a triangular leading edge wing feather, a rectangular leading edge wing feather or a rhombic leading edge wing feather.

[0010] Illustratively, the barb-shaped leading edge wing feather is a triangular leading edge wing feather with softened edges.

[0011] Further, the barb-shaped leading edge wing feather is a parrot beak-shaped barb-shaped leading edge wing feather.

[0012] In an embodiment of the present application, the barb-shaped leading edge wing feather can reduce the partial stall wing wake velocity difference and delay flow separation; for the fully stalled wing, a boundary layer splitter can be created to prevent stall from spreading outward.

[0013] Illustratively, one side of the curved leading edge wing feather is a curved edge, and the edge is formed by a plurality of feather tips of feathers arranged adjacent to each other to form a continuous curved edge.

[0014] Further, the plurality of feather tips of feathers are pointed top circular arcs, and the plurality of feather tips of feathers are inclined in the same direction or different directions.

[0015] In the present application, the bionic leading edge wing feather can suppress the separation of the boundary layer vortex, generate relatively higher lift, and at the same time play a role in flexibly adjusting the direction. Different shapes of bionic leading edge wing feathers produce different shapes and different numbers of vortex shapes, and the effects of suppressing boundary layer separation are different in strength.

[0016] The flow direction vortex shapes produced by different outer shape structures of the bionic leading edge wing feather 1 are different, and different flow direction vortex shapes result in different momentum transmission and vortex transfer. The size of the transferred momentum and the vortex transfer is related to the shape of the aircraft and the size and position of the shape.

[0017] Further, the bionic leading edge wing feather 1 is taken as the coordinate origin, the spanwise direction is taken as the x-axis, and the chordwise direction is taken as the y-axis.

[0018] The geometric length of the bionic leading edge wing feather 1 in the x-axis direction is not greater than 15% of the span length of the curved wing body 7.

[0019] The geometric length of the bionic leading edge wing feather 1 in the y-axis direction is not greater than 15% of the chord length of the curved wing body 7.

[0020] The geometric length of the bionic leading edge wing feather 1 and the proportion of the curved wing body in the present application are consistent with the biological characteristics of the old eagle in nature, and are closer to the actual biological scale size. The proportion is suitable for all shapes and sizes.

[0021] Further, when the bionic leading edge wing feather is arranged, the bionic leading edge wing feather can be arranged at any position in the interval from the leading edge wing root to the wing tip 5 of the curved wing body 7.

[0022] Illustratively, when the bionic leading edge wing feather is arranged, the bionic leading edge wing feather can be arranged at the leading edge 1 / 2 8, the leading edge 1 / 4 9, the leading edge 3 / 4 10 or the wing tip 5 of the curved wing body 7.

[0023] In an embodiment of the present application, the bionic leading edge wing feather 1 is coupled with the incoming flow to generate a streamwise vortex, which induces the momentum transfer and vortex transfer between the downwash flow of the bionic leading edge wing feather 1 and the inside of the boundary layer of the leading edge 2 of the curved wing body 7, thereby inhibiting the boundary layer separation of the leading edge 2 of the curved wing body 7, enhancing the lift-drag ratio and the stall angle of the aircraft; the characteristics of the streamwise vortex are autonomously controllable according to the bionic leading edge wing feather 1 of the curved wing body 7, and are adjusted according to the incoming flow environment and the performance requirements of the aircraft; the performance requirements of the aircraft include speed performance, deformation ability and control performance; the shape, size and direction of the streamwise vortex are adjusted by autonomously controlling the shape, size and angle of the leading edge wing feather, thereby changing the aerodynamic performance of the wing;

[0024] Further, the bionic leading edge wing feather 1 has a double-degree-of-freedom included angle; the double-degree-of-freedom included angle includes a spanwise included angle α and a chordwise included angle β; the direction and shape of the streamwise vortex are adjusted by changing the spanwise angle and the chordwise angle;

[0025] It can be understood that, with the center of the bionic leading edge wing feather 1 as the coordinate origin, the spanwise direction as the x-axis and the chordwise direction as the y-axis, the spanwise included angle α is formed and the chordwise included angle β is formed;

[0026] Further, the expression of the spanwise included angle α of the bionic leading edge wing feather 1 is:

[0027] α=f1(θ(t),γ(t),v(t))

[0028] Wherein, θ is the wing flapping angle, γ is the wing attack angle, η is the wing deflection angle, t is the time, and f1(·) is the spanwise included angle α limiting function;

[0029] The expression of the chordwise included angle β of the bionic leading edge wing feather 1 is:

[0030] β=f2(θ(t),γ(t),η(t))

[0031] Wherein, f2(·) is the chordwise included angle β limiting function.

[0032] Further, the selectable angle range of the spanwise included angle α is 0-π, and the selectable angle range of the chordwise included angle β is 0-π / 2.

[0033] For example, the spanwise angle α of the bionic leading edge feather 1 is π / 2; the chordwise angle β of the bionic leading edge feather 1 is π / 4.

[0034] Furthermore, the angle between the two degrees of freedom of the biomimetic leading edge feather 1 is determined based on the constraint conditions of the angle between the two degrees of freedom;

[0035] The constraint condition expression for the included angle of the two degrees of freedom is:

[0036] 0≤α≤π;

[0037] α s =f4(α,β,Re) 0≤α≤π;

[0038] Among them, C L / C D α is the lift-to-drag ratio of the wing. s C is the wing stall angle, Re is the Reynolds number; L C is the lift coefficient. D C represents the drag coefficient. L / C D α is the lift-to-drag ratio of the wing. s C is the wing stall angle, Re is the Reynolds number; L C is the lift coefficient. D f3(·) represents the drag coefficient, f4(·) is the limiting function for the lift-to-drag ratio of the wing, and f4(·) is the limiting function for the stall angle of the wing.

[0039] Furthermore, the angle between the two degrees of freedom of the biomimetic leading edge feather 1 changes dynamically with the flapping motion of the random wing, and the flapping wing flow structure is optimized in real time.

[0040] Furthermore, the biomimetic leading-edge feathers 1 are distributed on the leading edge 2 of the curved wing body 7; the number and position of the biomimetic leading-edge feathers 1 are variable;

[0041] Furthermore, the number of biomimetic leading-edge feathers 1 is determined by the shape characteristics of the curved wing body 7 and the performance of the aircraft;

[0042] Furthermore, the number of the biomimetic leading-edge feathers is expressed as:

[0043] l a ·n≤0.5l w

[0044] Where n is the number of biomimetic leading-edge feathers, l a To determine the base length of the biomimetic leading-edge wing feather 1, l w The leading edge length of the wing;

[0045] Exemplarily, the plurality of bionic leading edge wing feathers 1 are regularly distributed at equal intervals or irregularly distributed at unequal intervals on the leading edge 2 of the curved wing body 7.

[0046] It can be understood that when the wing overall stability is required to be enhanced, the plurality of bionic leading edge wing feathers 1 are regularly distributed at equal intervals on the leading edge of the wing; when the lift-drag ratio of a specific position of the wing is required to be enhanced to realize the stable steering of the aircraft, the plurality of bionic leading edge wing feathers 1 are irregularly distributed at unequal intervals on the leading edge of the wing.

[0047] Further, the bionic leading edge wing feather and the curved wing body are integrally formed by 3D printing and assembled by using a hinge structure; the hinge structure is smoothly connected with the curved wing body.

[0048] The bionic wing feather structure does not change the existing wing aerodynamic shape, and only a small-scale spoiler structure is added on the leading edge to complete the hardware design, so that the overall structure is simple and easy to maintain; through free control of the characteristic shape, number and angle of the wing feather, the aerodynamic performance of the flapping wing unmanned aerial vehicle serving different flight conditions and performance requirements is improved.

[0049] Compared with the prior art, the present application has at least the following beneficial effects:

[0050] (1) The wing based on the bionic leading edge wing feather of the present application enhances the aerodynamic performance of the flapping wing, and the bionic wing feather structure is added on the leading edge of the wing to interact with the free flow to generate a streamwise vortex pair, thereby inducing the momentum transfer and vortex transfer between the downwash flow and the leading edge boundary layer, inhibiting / improving the flow separation in the large attack angle state, and then enhancing the wing aerodynamic performance, thereby laying a foundation for the high maneuvering flight of the flapping wing aircraft;

[0051] (2) The wing based on the bionic leading edge wing feather of the present application enhances the aerodynamic performance of the flapping wing, and the shape and number of the leading edge wing feather structure can be freely adjusted according to the performance requirements of the aircraft, thereby generating streamwise vortices with different vorticity, shape and number, realizing the multifunctional adjustment of the size, direction and shape of the leading edge flow, and being applicable to multiple flight environments such as multi-directional incoming flow, aircraft steering and aircraft lift hovering, thereby improving the application range;

[0052] (3) The wing based on the bionic leading edge wing feather of the present application enhances the aerodynamic performance of the flapping wing, and the two-degree-of-freedom angle of the wing feather structure changes autonomously during the flapping of the wing, thereby realizing the maximization of the aerodynamic efficiency at each moment during the service of the aircraft, ensuring the service safety of the aircraft, and effectively improving the endurance and load capacity of the aircraft;

[0053] (4) The wing based on the bionic leading edge wing feather of the application for enhancing the flapping wing aerodynamic performance, the size of the bionic leading edge wing feather is small, the flow around the flapping wing leading edge is regulated, in the flow control field, it belongs to passive flow control, the control effect is positively correlated with the flight speed, only the energy input required is the control of the wing feather angle, and the whole is low in consumption and high in efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0054] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application.

[0055] Figure 1 FIG. 1 is a schematic diagram of the overall structure of the wing based on the bionic leading edge wing feather of the application for enhancing the flapping wing aerodynamic performance in an embodiment of the application;

[0056] Figure 2 FIG. 2 is a schematic diagram of the aerodynamic principle of the bionic leading edge wing feather in an embodiment of the application;

[0057] Figure 3 FIGS. (a)-(f) are schematic diagrams of the characteristic shape of the bionic leading edge wing feather in an embodiment of the application;

[0058] Figure 4 FIG. 4 is a schematic diagram of the two-degree-of-freedom angle change of the bionic leading edge wing feather in an embodiment of the application;

[0059] Figure 5 FIG. 5 is a schematic diagram of the layout strategy of the bionic leading edge wing feather in an embodiment of the application.

[0060] Reference signs:

[0061] 1. Bionic leading edge wing feather, 2. Leading edge, 3. Bottom length, 4. Wing root, 5. Wing tip, 6. Trailing edge, 7. Curved wing body, 8. 1 / 2 of the leading edge, 9. 1 / 4 of the leading edge, 10. 3 / 4 of the leading edge. DETAILED DESCRIPTION

[0062] In order to enable a clearer understanding of the above-mentioned purposes, features and advantages of the application, the application will be further described in detail below in combination with the drawings and specific embodiments. It should be noted that the embodiments of the application and the features in the embodiments can be combined with each other without conflict. In addition, the application can also be implemented in other ways different from those described herein, and therefore, the protection scope of the application is not limited by the specific embodiments disclosed below.

[0063] One specific embodiment of the application, as Figures 1-5 , discloses a wing based on the bionic leading edge wing feather for enhancing the flapping wing aerodynamic performance. In order to illustrate the effectiveness of the method of the application, the above technical solution of the application will be described in detail below through a specific embodiment, and the specific implementation steps are as follows:

[0064] The application provides a wing based on bionic leading edge wing feather for enhancing flapping wing aerodynamic performance, comprising at least one bionic leading edge wing feather 1 and a curved wing body 7; the wing is a wing of a flapping wing unmanned aerial vehicle;

[0065] The curved wing body 7 comprises a leading edge 2, a wing root 4, a wing tip 5 and a trailing edge 6;

[0066] Preferably, the at least one bionic leading edge wing feather 1 is arranged on the leading edge 2 of the curved wing body 7 to form a convex independent structure.

[0067] Further, the outer shape structure of the bionic leading edge wing feather 1 is freely adjusted according to the performance requirement of the aircraft, including a barb-shaped leading edge wing feather Figure 3 (a), a curved leading edge wing feather Figure 3 (b), a semicircular leading edge wing feather Figure 3 (c), a triangular leading edge wing feather Figure 3 (d), a rectangular leading edge wing feather Figure 3 (e) or a rhombic leading edge wing feather Figure 3 (f);

[0068] Illustratively, the barb-shaped leading edge wing feather is a triangular leading edge wing feather with softened edges.

[0069] Further, the barb-shaped leading edge wing feather is a barb-shaped leading edge wing feather in the shape of a parrot beak.

[0070] In an embodiment of the application, the barb-shaped leading edge wing feather can reduce the difference in wake speed of a partially stalled wing and delay flow separation; for a completely stalled wing, the barb-shaped leading edge wing feather can create a boundary layer splitter to prevent stall from spreading outward.

[0071] Illustratively, one side of the curved leading edge wing feather is a curved edge, and the curved edge is formed by a plurality of feather tips of feathers arranged adjacent to each other to form a continuous curved edge.

[0072] Further, the plurality of feather tips of the feathers are arc-shaped with pointed tips, and the plurality of feather tips of the feathers are inclined in the same direction or different directions.

[0073] In the application, the bionic leading edge wing feather can suppress the separation of boundary layer vortices, generate relatively higher lift, and play a role in flexibly adjusting the direction. Different shapes of the bionic leading edge wing feather produce different shapes and different amounts of vortex shapes, and the effects of suppressing boundary layer separation are different in strength.

[0074] The flow direction vortex shapes produced by different outer shape structures of the bionic leading edge wing feather 1 are different, and different flow direction vortex shapes result in different momentum transmission and vortex transfer. The size of the transferred momentum and the vortex transfer is related to the shape of the aircraft and the size and position of the shape.

[0075] Further, the bionic leading edge wing feather 1 has a center as a coordinate origin, a spanwise direction as an x-axis, and a chordwise direction as a y-axis.

[0076] The geometric length of the bionic leading edge wing feather 1 in the x-axis direction is not greater than 15% of the span of the curved wing body 7.

[0077] The geometric length of the bionic leading edge wing feather 1 in the y-axis direction is not greater than 15% of the chord of the curved wing body 7.

[0078] The ratio of the geometric length of the bionic leading edge wing feather 1 to the curved wing body is consistent with the biological characteristics of a hawk in nature, and is closer to the actual biological size, and the ratio is suitable for all shapes and sizes.

[0079] Further, when one bionic leading edge wing feather is arranged, the bionic leading edge wing feather can be arranged at any position in the interval from the leading edge wing root to the wing tip of the curved wing body 7.

[0080] For example, when one bionic leading edge wing feather is arranged, the bionic leading edge wing feather is arranged at the leading edge 1 / 2 of the curved wing body 7, the leading edge 1 / 4 of the curved wing body 7, the leading edge 3 / 4 of the curved wing body 7, or the wing tip 5 of the curved wing body 7.

[0081] In an embodiment of the present application, the bionic leading edge wing feather 1 and the flow coupling generate a streamwise vortex, the streamwise vortex induces the downwash flow of the bionic leading edge wing feather 1 and the momentum transfer and vortex transfer between the boundary layer inside the leading edge 2 of the curved wing body 7, thereby inhibiting the boundary layer separation of the leading edge 2 of the curved wing body 7, enhancing the lift-drag ratio of the flapping wing, and increasing the stall angle; the characteristics of the streamwise vortex are autonomously controllable according to the bionic leading edge wing feather 1 of the curved wing body 7, and are adjusted according to the flow environment and the performance requirements of the aircraft; the performance requirements of the aircraft include speed performance, deformation ability, and control performance; the shape, size, and direction of the streamwise vortex are adjusted by autonomously controlling the shape, size, and angle of the leading edge wing feather, thereby changing the aerodynamic performance of the wing;

[0082] Further, the bionic leading edge wing feather 1 has a double-degree-of-freedom included angle; the double-degree-of-freedom included angle includes a spanwise included angle α and a chordwise included angle β; the direction and shape of the streamwise vortex are adjusted by changing the spanwise angle and the chordwise angle.

[0083] It can be understood that the center of the bionic leading edge wing feather 1 is taken as a coordinate origin, the spanwise direction is taken as an x-axis, and the chordwise direction is taken as a y-axis, to form a spanwise included angle α and a chordwise included angle β.

[0084] Further, the expression of the spanwise included angle α of the bionic leading edge wing feather is as follows:

[0085] α=f1(θ(t),γ(t),η(t))

[0086] Where θ is the wing flapping angle, γ is the wing angle of attack, η is the wing deflection angle, t is time, and f1(·) is the spanwise angle α constraint function;

[0087] The expression for the chordal angle β of the biomimetic leading-edge feathers is:

[0088] β=f2(θ(t),γ(t),η(t))

[0089] Where f2(·) is a constraint function for the chordal angle β.

[0090] Furthermore, the selectable angle range of the spanwise included angle α is 0 to π, and the selectable angle range of the chordwise included angle β is 0 to π / 2.

[0091] For example, the spanwise angle α of the bionic leading edge feathers is π / 2; the chordwise angle β of the bionic leading edge feathers is π / 4.

[0092] Furthermore, the angle between the two degrees of freedom of the biomimetic leading-edge feathers is determined based on the constraint conditions of the angle between the two degrees of freedom;

[0093] The constraint condition expression for the included angle of the two degrees of freedom is:

[0094] 0≤α≤π;

[0095] α s =f4(α,β,Re) 0≤α≤π;

[0096] Among them, C L / C D α is the lift-to-drag ratio of the wing. s C is the wing stall angle, Re is the Reynolds number; L C is the lift coefficient. D C represents the drag coefficient. L / C D α is the lift-to-drag ratio of the wing. s C is the wing stall angle, Re is the Reynolds number; L C is the lift coefficient. D f3(·) represents the drag coefficient, f4(·) is the limiting function for the lift-to-drag ratio of the wing, and f4(·) is the limiting function for the stall angle of the wing.

[0097] Furthermore, the angle between the two degrees of freedom of the biomimetic leading edge feather 1 changes dynamically with the flapping motion of the random wing, and the flapping wing flow structure is optimized in real time.

[0098] Furthermore, the biomimetic leading-edge feathers 1 are distributed on the leading edge 2 of the curved wing body 7; the number and position of the biomimetic leading-edge feathers 1 are variable;

[0099] Further, the number of the bionic leading edge wing feathers 1 is determined by the shape characteristics of the curved wing body 7 and the performance of the aircraft.

[0100] Further, the number of the bionic leading edge wing feathers is expressed as:

[0101] l a ·n≤0.5l w

[0102] Wherein, n is the number of the bionic leading edge wing feathers, l a is the bottom length of the bionic leading edge wing feather 1 structure, l w is the length of the leading edge of the wing.

[0103] Exemplarily, the plurality of bionic leading edge wing feathers 1 are regularly distributed at equal intervals or irregularly distributed at unequal intervals on the leading edge 2 of the curved wing body 7.

[0104] It can be understood that when the overall stability of the wing is required to be enhanced, the plurality of bionic leading edge wing feathers 1 are regularly distributed at equal intervals on the leading edge of the wing; when the lift-drag ratio of a specific position of the wing is required to be improved to realize the stable steering of the aircraft, the plurality of bionic leading edge wing feathers 1 are irregularly distributed at unequal intervals on the leading edge of the wing.

[0105] Further, the bionic leading edge wing feathers and the curved wing body are integrally formed by 3D printing and assembled by a hinge structure, and the hinge structure is smoothly connected with the curved wing body.

[0106] The present application introduces the bionic wing feather structure into the leading edge of the wing to form a vortex pair, improves the evolution law of the boundary layer of the leading edge of the wing, suppresses / improves the separation phenomenon of the boundary layer at high attack angle of the flapping wing, and improves the aerodynamic performance of the flapping wing unmanned aerial vehicle. The bionic wing feather structure does not change the existing aerodynamic shape of the wing, and only a small-scale spoiler structure is added to the leading edge to complete the hardware design, so that the overall structure is simple and easy to maintain. Through the free control of the characteristic shape, number and angle of the wing feather, the aerodynamic performance of the flapping wing unmanned aerial vehicle serving different flight conditions and performance requirements is improved.

[0107] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A wing for enhancing the aerodynamic performance of a flapping wing based on a bionic leading edge wing feather, characterized in that, The application relates to a wing-body configuration of a flapping wing aircraft, comprising: a curved wing-body (7) and at least one bionic leading edge wing feather (1); the at least one bionic leading edge wing feather (1) is arranged at the leading edge of the curved wing-body (7) to form a convex independent structure; the bionic leading edge wing feather (1) is coupled with the airflow to generate a streamwise vortex, the induced downwash flow of the streamwise vortex is subjected to momentum transfer and vortex transfer with the inside of the boundary layer of the leading edge of the curved wing-body (7), the boundary layer separation of the leading edge of the curved wing-body (7) is inhibited, and then the lift-drag ratio and the stall angle of the flapping wing are enhanced; the outer shape structure of the bionic leading edge wing feather (1) is freely adjusted according to the performance requirement of the aircraft, and the bionic leading edge wing feather includes a barb-shaped leading edge wing feather, a curved leading edge wing feather, a semicircular leading edge wing feather, a triangular leading edge wing feather, a rectangular leading edge wing feather or a rhombic leading edge wing feather; With the center of the wing feather as the coordinate origin, along the wing feather span direction as x the axis, the chord direction as y the axis, the geometric length of the bionic leading edge wing feather (1) in x the axis direction is not greater than 15% of the span length of the curved wing body (7); in y the axis direction, the geometric length is not greater than 15% of the chord length of the curved wing body (7); the bionic leading edge wing feather (1) is arranged at any position in the wing root-to-wing tip (5) interval of the leading edge of the curved wing-body (7); The bionic leading edge wing feather (1) has a double-degree-of-freedom included angle; the double-degree-of-freedom included angle includes a spanwise included angle α and a chordwise included angle β ​ the double-degree-of-freedom included angle random wing flapping motion is dynamically changed, and the flapping wing flow structure is optimized in real time; The spanwise included angle of the biomimetic leading edge wing feather (1) α The expression is: wherein, theta is a wing flapping angle, gamma is a wing angle of attack, eta is a wing angle of declination, t is time, (·) is a spanwise included angle α limiting function; The chord-wise included angle of the biomimetic leading edge wing feather (1) β The expression is: wherein (·) is the chord-wise angle β limit function.

2. The bionic leading edge wing feather based wing to enhance flapping aerodynamic performance according to claim 1, characterized in that, The optional angle range of the spanwise included angle α is 0~π, and the optional angle range of the chordwise included angle β is 0~π / 2.

3. The bionic leading edge wing feather based wing to enhance flapping aerodynamic performance according to claim 1, characterized in that, the double-degree-of-freedom included angle of the bionic leading edge wing feather (1) is determined based on a constraint condition of the double-degree-of-freedom included angle; the constraint condition of the double-degree-of-freedom included angle is expressed as: wherein C L / C D is the wing lift-to-drag ratio, α s is the wing stall angle, Re is the Reynolds number; C L is the lift coefficient, C D represents the drag coefficient, (·) is a limiting function of the wing lift-to-drag ratio, (·) is a limiting function of the wing stall angle.

4. The bionic leading edge wing feather based wing to enhance flapping aerodynamic performance according to claim 1, characterized in that, a plurality of bionic leading edge wing feathers (1) are regularly distributed at equal intervals or irregularly distributed at non-equal intervals at the leading edge of the curved wing-body (7).

Images