Bionic wing

Abstract

The invention discloses a bionic wing. The bionic wing comprises a wing main body, a bionic sawtooth front edge structure and a bionic comb-shaped rear edge structure, the bionic sawtooth front edge structure is arranged on the front edge of a wing main body and comprises a plurality of triangular sawteeth, and the triangular sawteeth are arranged in the spanwise direction of the front edge of the wing main body; the bionic comb-shaped trailing edge structure is arranged on the trailing edge of the wing main body, the bionic comb-shaped trailing edge structure comprises a plurality of comb teeth, the comb teeth are arranged in the spanwise direction of the trailing edge of the wing main body, each comb tooth is provided with an inner groove channel, and the inner groove channels extend inwards from the ends of the comb teeth; the bionic sawtooth front edge structure and the bionic comb-shaped rear edge structure both belong to feather bionic structure characteristics of an owl, so that the feather bionic characteristics of the owl are combined with the wing main body, the airflow separation noise is inhibited through the bionic sawtooth front edge structure, and the vortex shedding strength is weakened through the bionic comb-shaped rear edge structure; the aerodynamic noise is obviously reduced while the high aerodynamic efficiency of the wing main body is kept.

Description

Technical Field

[0001] The invention relates to the technical field of wings, in particular to a bionic wing. Background Art

[0002] As a symmetrical airfoil with high lift-to-drag ratio and structural stability, NACA0015 is widely used in the design of aircraft wings, wind turbine blades and propellers. However, under high-speed or high-angle-of-attack conditions, the symmetrical geometric characteristics are prone to flow separation, resulting in significant trailing edge vortex shedding noise. Studies have shown that at low Reynolds numbers (Re≈5×105) and high angles of attack (AOA≥12°), the trailing edge separation and TS wave coupling of the NACA0015 airfoil will cause pure tone noise. This type of noise is more prominent and complex in high-speed dynamic rotor systems, directly causing the noise of low-altitude aircraft to exceed the urban environmental noise limit (less than 65dB).

[0003] In order to reduce aerodynamic noise from the source, in addition to the traditional method of optimizing the design of various airfoil parameters, bionics technology has gradually become a research hotspot. Owl feathers have attracted widespread attention due to their unique silent flight characteristics. Their unique comb-like structure, serrated structure and surface flexible fluff have all contributed to the reduction of aerodynamic noise. At present, some studies have applied the above structures to airfoil design. The Clark team in the UK designed based on the fine fluff characteristics of the owl feather surface and reduced the DU96-W180 airfoil noise by 10dB through 3D printing of bionic trailing edge accessories (Clark et al, 2015); Qiu Junfeng of Jiangsu University introduced a bionic serrated structure on the trailing edge of NACA0015 and found that the sawtooth aspect ratio and passivation ratio had a significant effect on suppressing low-frequency noise (noise reduction of 5dB in the 450-600Hz frequency band).

[0004] Although there have been some applications of bionic noise reduction, it is difficult to achieve a balance between aerodynamic and acoustic performance. Some designs even reduce the aerodynamic performance of the airfoil. In addition, most applications use a single bionic structure, while the coordinated application of multiple structures is rare. Summary of the invention

[0005] The purpose of the present invention is to provide a bionic wing to solve the problem that it is difficult to balance aerodynamic and acoustic performance in the prior art.

[0006] In order to solve the above technical problems, the present invention provides a bionic wing, comprising a wing body, a bionic serrated leading edge structure and a bionic comb-like trailing edge structure; the bionic serrated leading edge structure is arranged at the leading edge of the wing body, the bionic serrated leading edge structure comprises a plurality of triangular serrations, and the plurality of triangular serrations are arranged in the span direction of the leading edge of the wing body; the bionic comb-like trailing edge structure is arranged at the trailing edge of the wing body, the bionic comb-like trailing edge structure comprises a plurality of comb teeth, the plurality of comb teeth are arranged in the span direction of the trailing edge of the wing body, and the plurality of comb teeth are provided with inner groove channels, and the inner groove channels extend inwardly from the ends of the comb teeth.

[0007] In one embodiment, the bionic wing is a NACA0015 airfoil.

[0008] In one embodiment, the bionic sawtooth leading edge structure is connected to the leading edge of the wing body by mortise and tenon joints.

[0009] In one of the embodiments, the bionic sawtooth leading edge structure is provided with a front tenon, the leading edge of the wing body is provided with a front mortise, and the front tenon is connected to the front mortise by mortise and tenon joints.

[0010] In one embodiment, the sawtooth height of the triangular sawtooth is 3-5 mm, and the tooth spacing between adjacent triangular sawtooths is 2.2-2.6 mm.

[0011] In one embodiment, the bionic comb-shaped trailing edge structure is connected to the trailing edge of the wing body by mortise and tenon joints.

[0012] In one of the embodiments, the bionic comb-shaped trailing edge structure is provided with a rear tenon, the trailing edge of the wing body is provided with a rear mortise, and the rear tenon is mortise-jointed with the rear mortise.

[0013] In one of the embodiments, the thickness of the comb teeth is 1.8-2.2 mm, the spacing between adjacent comb teeth is 2-2.1 mm, and the length of the inner groove is 8-12 mm.

[0014] In one of the embodiments, the comb teeth include two oppositely arranged half teeth, the ends of the two half teeth are arc-shaped, and the inner groove channel is formed between the two half teeth.

[0015] In one embodiment, the height of the half teeth is 3 to 5 mm.

[0016] The beneficial effects of the present invention are as follows:

[0017] In the present invention, the bionic serrated leading edge structure and the bionic comb-like trailing edge structure are both bionic structural features of owl feathers, so the present invention combines the bionic features of owl feathers with the wing body, suppresses the airflow separation noise through the bionic serrated leading edge structure, and weakens the vortex shedding strength through the bionic comb-like trailing edge structure, while maintaining the high aerodynamic efficiency of the wing body, significantly reducing aerodynamic noise. This design can be applied to scenarios such as eVTOL wing design, propeller blades, multi-rotor UAV propulsion systems, and ducted fans of urban logistics aircraft. In addition, the invention can also be extended to small wind turbine blades, high-speed railway noise reduction deflectors, and other fluid mechanical devices that need to take into account both efficiency and acoustic performance, and has cross-domain engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a structural schematic diagram provided by an embodiment of the present invention;

[0020] Figure 2 yes Figure 1 Schematic diagram of the main structure of the wing;

[0021] Figure 3 yes Figure 1 Schematic diagram of the bionic sawtooth leading edge structure;

[0022] Figure 4 It is a schematic diagram of the triangular sawtooth dimensions of the bionic sawtooth leading edge structure;

[0023] Figure 5 yes Figure 1 Schematic diagram of the bionic comb-shaped trailing edge structure;

[0024] Figure 6 This is a schematic diagram of the size of the bionic comb-shaped trailing edge structure. Figure 1 ;

[0025] Figure 7 This is a schematic diagram of the size of the bionic comb-shaped trailing edge structure. Figure 2 ;

[0026] Figure 8 It is a graph showing the change of sound pressure levels of the NACA0015 airfoil and the present invention at different wind speeds;

[0027] Fig. 9 It is the spectrum diagram of NACA0015 airfoil and the present invention;

[0028] Fig.10It is a curve diagram of the lift-drag coefficient variation of the NACA0015 airfoil and the present invention at different wind speeds at a low angle of attack of 5°.

[0029] The reference numerals are as follows:

[0030] 10. Wing body; 11. Front mortise; 12. Rear mortise;

[0031] 20. Bionic sawtooth front edge structure; 21. Triangular sawtooth; 22. Front tenon;

[0032] 30. Bionic comb-like rear edge structure; 31. Comb teeth; 32. Inner groove channel; 33. Rear tenon; 34. Half teeth. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0034] The present invention provides a bionic wing, which can be implemented as follows: Figure 1 As shown, it includes a wing body 10 , a bionic sawtooth leading edge structure 20 and a bionic comb-shaped trailing edge structure 30 .

[0035] Regarding the wing body 10, Figure 1 As shown, in this embodiment, the bionic wing is configured as a NACA0015 airfoil, so the shape of the wing body 10 will be designed with reference to the NACA0015 airfoil to ensure that the bionic wing can obtain various excellent performances of the NACA0015 airfoil.

[0036] Regarding the bionic sawtooth leading edge structure 20, Figure 1 , Figure 3 and Figure 4 As shown, in this embodiment, a bionic sawtooth leading edge structure 20 is arranged at the leading edge of the wing body 10 . The bionic sawtooth leading edge structure 20 includes a plurality of triangular sawteeth 21 . The plurality of triangular sawteeth 21 are arranged along the span direction of the leading edge of the wing body 10 .

[0037] Among them, in order to reduce the impact of additional surface pressure brought by the introduction of the new structure, this embodiment arranges the bionic serrated leading edge structure 20 and the leading edge of the wing body 10 to be connected by mortise and tenon. At this time, the bionic serrated leading edge structure 20 is provided with a front tenon 22, and the leading edge of the wing body 10 is provided with a front mortise 11, and the front tenon 22 is connected with the front mortise 11 by mortise and tenon; of course, it is also a feasible way to change the front tenon 22 to be arranged at the leading edge of the wing body 10 and the front mortise 11 to be arranged at the bionic serrated leading edge structure 20.

[0038] In addition, the design parameters of the triangular sawtooth 21 will have an important impact on the performance of the bionic wing, so Figure 4As shown, in this embodiment, the sawtooth height of the triangular sawtooth 21 is set to 4 mm, and the tooth spacing between adjacent triangular sawtooths 21 is set to 2.4 mm.

[0039] It should be pointed out that the above setting parameters are not unique and technicians can adjust them according to actual conditions, but it is recommended to set the sawtooth height of the triangular sawtooth 21 to 3-5 mm and the tooth spacing between adjacent triangular sawtooth 21 to 2.2-2.6 mm.

[0040] Regarding the bionic comb-shaped trailing edge structure 30, Figure 1 ,as well as Figures 5 to 7 As shown, this embodiment provides a bionic comb-like trailing edge structure 30 disposed at the trailing edge of the wing body 10, and the bionic comb-like trailing edge structure 30 includes a plurality of comb teeth 31, and the plurality of comb teeth 31 are arranged along the trailing edge span direction of the wing body 10, and the plurality of comb teeth 31 are each provided with an inner groove channel 32, and the inner groove channel 32 is extended inward from the end of the comb tooth 31.

[0041] Among them, in order to reduce the additional surface pressure impact brought by the introduction of the new structure, this embodiment arranges the bionic comb-like trailing edge structure 30 and the trailing edge of the wing body 10 to be connected by mortise and tenon. At this time, the bionic comb-like trailing edge structure 30 is provided with a rear tenon 33, and the trailing edge of the wing body 10 is provided with a rear mortise 12, and the rear tenon 33 and the rear mortise 12 are connected by mortise and tenon; of course, it is also a feasible way to change the rear tenon 33 to be arranged at the trailing edge of the wing body 10, and change the rear mortise 12 to be arranged at the bionic comb-like trailing edge structure 30.

[0042] In addition, the shape and related design parameters of the comb teeth 31 will have an important impact on the performance of the bionic wing, so Figures 5 to 7 As shown, in this embodiment, the comb teeth 31 include two oppositely arranged half teeth 34, the ends of the two half teeth 34 are arc-shaped, and an inner groove channel 32 is formed between the two half teeth 34. At this time, the thickness of the comb teeth 31 is 22mm, the spacing between adjacent comb teeth 31 is 2.05mm, the length of the inner groove channel 32 is 10mm, and the height of the half teeth 34 is 4mm.

[0043] It should be pointed out that the above setting parameters are not unique and technicians can adjust them according to actual conditions, but it is recommended to set the thickness of the comb teeth 31 to 1.8-2.2 mm, the spacing between adjacent comb teeth 31 to 2-2.1 mm, the length of the inner groove channel 32 to 8-12 mm, and the height of the half tooth 34 to 3-5 mm.

[0044] from Figure 8 and Fig. 9It can be seen that the leading edge and the trailing edge have different effects on the airfoil noise suppression in different wind speed ranges. Therefore, combining the leading edge and the trailing edge with the optimal parameters does not necessarily achieve the highest noise reduction efficiency on the airfoil. According to the data, in the wind speed range of 15m / s to 24m / s, the noise attenuation of the bionic wing described in the above embodiment is the largest (5dB, v = 20m / s); however, it is worth noting that at a frequency of 1350Hz, especially when the wind speed is 24m / s, the noise peak is completely suppressed.

[0045] And from Fig.10 It can be seen that at low angle of attack (AOA = 5°), compared with the prototype NACA0015 airfoil, the drag coefficient and lift coefficient of the bionic wing described in the above embodiment are improved at the same time. Although the synergistic structure enhances the drag, the positive benefit brought by the lift is more significant. This design achieves aerodynamic noise control while ensuring aerodynamic performance.

[0046] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A bionic wing, characterized in that: It includes a wing body, a bionic sawtooth leading edge structure and a bionic comb-shaped trailing edge structure; The bionic sawtooth leading edge structure is arranged at the leading edge of the wing body, and the bionic sawtooth leading edge structure comprises a plurality of triangular sawteeth, and the plurality of triangular sawteeth are arranged along the leading edge of the wing body in a span direction; The bionic comb-like trailing edge structure is arranged at the trailing edge of the wing body, and the bionic comb-like trailing edge structure includes a plurality of comb teeth, and the plurality of comb teeth are arranged in the span direction along the trailing edge of the wing body, and the plurality of comb teeth are provided with inner groove channels, and the inner groove channels extend inwardly from the ends of the comb teeth.

2. The bionic wing according to claim 1, characterized in that: The bionic wing is a NACA0015 airfoil.

3. The bionic wing according to claim 1, characterized in that: The bionic sawtooth leading edge structure is connected to the leading edge of the wing body by mortise and tenon joints.

4. The bionic wing according to claim 3, characterized in that: The bionic sawtooth leading edge structure is provided with a front tenon, the leading edge of the wing body is provided with a front mortise, and the front tenon is connected with the front mortise by mortise and tenon joints.

5. The bionic wing according to claim 1, characterized in that: The sawtooth height of the triangular sawtooth is 3-5 mm, and the tooth spacing between adjacent triangular sawtooths is 2.2-2.6 mm.

6. The bionic wing according to claim 1, characterized in that: The bionic comb-shaped trailing edge structure is connected to the trailing edge of the wing body by mortise and tenon joints.

7. The bionic wing according to claim 6, characterized in that: The bionic comb-shaped trailing edge structure is provided with a rear tenon, the trailing edge of the wing body is provided with a rear mortise, and the rear tenon is connected with the rear mortise by mortise and tenon joints.

8. The bionic wing according to claim 1, characterized in that: The thickness of the comb teeth is 1.8-2.2 mm, the spacing between adjacent comb teeth is 2-2.1 mm, and the length of the inner groove channel is 8-12 mm.

9. The bionic wing according to claim 1, characterized in that: The comb teeth include two half teeth arranged opposite to each other, the ends of the two half teeth are arc-shaped, and the inner groove channel is formed between the two half teeth.

10. The bionic wing according to claim 9, characterized in that: The height of the half teeth is 3 to 5 mm.

Images