Fan blade and fan

Abstract

The application discloses a fan blade and a fan. The blade is divided into multiple different structural sections from a blade root to a blade tip. Different structural sections have different airfoils. The airfoil cross sections of different structural sections from the blade root to the blade tip are the same as the airfoil cross sections taken in the wingspan direction. The blade is segmented in the length direction. Different sections of the blade are segmented according to different airfoils of owls. The bionics is simplified. The pressure difference between the upper surface and the lower surface of the fan blade is increased. The aerodynamic noise is reduced by using the airfoil principle of the owl. The structural sections have the same airfoil structure as the corresponding part of the owl airfoil. The structural sections have the same noise reduction effect as the part of the owl airfoil. The noise reduction and the cost are comprehensively optimized. The blade has good structural strength.

Description

Fan blades and fan Technical Field

[0001] This invention relates to the field of wind turbine technology, and particularly to wind turbine blades and wind turbines. Background Technology

[0002] With the development of technology, the application of axial flow fans has gradually increased, and the aerodynamic noise of the fans themselves has also received attention. Traditional noise reduction methods, such as adding serrated trailing edges and wavy leading edges, can effectively reduce the aerodynamic noise of the blades, but often affect their aerodynamic performance.

[0003] As an interdisciplinary field, bionics in engineering aims to solve engineering problems using biological characteristics and structures. The silent flight capabilities of owls offer new insights for wind turbine design. Using suitable owl-shaped airfoils in wind turbine design can effectively improve aerodynamic performance and reduce aerodynamic noise. However, the overall structure of owl-shaped airfoils is complex and feather-like. Due to production costs and material limitations, wind turbine blades cannot be manufactured with the exact same structure as owl-shaped airfoils. Therefore, how to biomimeticly create practical blades using the noise reduction principles of owl-shaped airfoils has become a pressing technical problem for the industry. Summary of the Invention

[0004] To address the practical application of owl-inspired airfoil-shaped bionic blades, this invention proposes segmenting the blade along its length, allowing different segments to correspond to different airfoil sections of an owl, thus simplifying the bionic design and reducing aerodynamic noise by utilizing the principles of owl airfoils.

[0005] The technical solution adopted in this invention is to design a wind turbine blade that is divided into multiple different structural segments from the blade root to the blade tip. The different structural segments have different airfoils, and the airfoil cross-sections of the different structural segments from the blade root to the blade tip have the same shape as the airfoil cross-sections taken sequentially in the span direction.

[0006] In some embodiments, the leaf is divided into three structural segments from the leaf root to the leaf tip, and the three structural segments from the leaf root to the leaf tip are respectively located in the 0-35% region, the 35%-70% region, and the 70%-100% region of the leaf length.

[0007] In some implementations, the distance between the three airfoil sections taken sequentially along the owl's wingspan is equal.

[0008] In some embodiments, the three airfoil sections are located sequentially at 40%, 50%, and 60% of the owl's wingspan.

[0009] In some embodiments, the trailing edge of the blade is provided with feather tip structures along the length of the blade, which are provided with the trailing edge feather tips of a biomimetic owl wing.

[0010] In some embodiments, a groove is provided between adjacent feather tip structural units.

[0011] In some embodiments, the end of the groove facing the leading edge of the blade has a Y-shaped guide slot that is inclined relative to the blade surface.

[0012] In some embodiments, the tail end of the feather-tip structural unit has a serrated tip.

[0013] In some embodiments, α is the length of the Y-shaped guide groove, β is the length of the feather tip structural unit, γ is the width of the feather tip structural unit, δ is the length of the V-shaped portion of the Y-shaped guide groove, ε is the length of the serrated tip of the feather tip structural unit, θ is the included angle of the V-shaped portion of the Y-shaped guide groove, ω is the tilt angle of the Y-shaped guide groove relative to the blade surface, and υ is the included angle between adjacent serrated tips. The three structural segments are the leaf root structural segment, the leaf mid-segment structural segment, and the leaf tip structural segment. In the leaf root structural segment, the above parameters are: α = 0.115 mm, β = 0 mm. The parameters for the leaf midsection are: α = 0.12 mm, β = 0.18 mm, γ = 0.0875 mm, δ = 0.0636 mm, ε = 0.072 mm, θ = 135°, ω = 35°, υ = 146°; for the leaf tip section, the parameters are: α = 0.14 mm, β = 0.16 mm, γ = 0.051 mm, δ = 0.073 mm, ε = 0.0672 mm, θ = 90°, ω = 30°, υ = 120°.

[0014] In some embodiments, the curve equation of the profile of half an edge of the serration tip is: y = a1x + a2x 2 +a3x 3 +c1; where a1=-3.52291±0.25801, a2=0.04044±0.00633, a3=-2.20532E-4±4.10959E-5, c1=170.67234±2.1376, y is the length of the saw tip, and x is the length and width of the saw tip.

[0015] In some embodiments, the size of the feather tip structures on different structural units is different, and the feather tip structural units on the structural segment decrease in size sequentially from the leaf root to the leaf tip.

[0016] Fans, including the aforementioned fan blades.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This invention segments the blade along its length, biomimicking different segments of an owl's airfoil to simplify biomimicry, increase the pressure difference between the upper and lower surfaces of the wind turbine blade, and enhance its work capacity. Simultaneously, it utilizes the owl airfoil principle to reduce aerodynamic noise. Each structural segment has the same airfoil structure as the corresponding part of an owl's wing, thus achieving the same noise reduction effect. Because each structural segment uses the same cross-sectional airfoil, manufacturing is easy and cost-effective. Suitable cross-sectional airfoils can be selected for each structural segment, resulting in a comprehensive optimization of noise reduction and cost, while ensuring good structural strength of the blade.

[0019] This invention employs a coupled structure of a Y-shaped groove and a serrated trailing edge at the trailing edge of the wind turbine blade. By guiding and cutting the airflow, it delays the detachment of vortices from the blade surface and cuts the vortices to reduce aerodynamic noise. The design concept of the coupled structure is to create a groove at the trailing edge of the blade, with structural units working in pairs to form a Y-shaped groove tail end. A serrated trailing edge is then added to the groove tail end, and the profile of the serrated trailing edge is optimized according to a teardrop shape to further reduce the aerodynamic noise of the wind turbine. Attached Figure Description

[0020] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings. To illustrate the details and facilitate understanding of its principles, the drawings are not necessarily to scale, and similar reference numerals may describe similar components in different views. The accompanying drawings generally illustrate the embodiments discussed herein by way of example and not limitation. Wherein:

[0021] Figure 1 is a schematic diagram of the blade in an embodiment.

[0022] Figure 2 is a schematic diagram of the fan in the embodiment.

[0023] Figure 3 is a schematic diagram comparing the external shapes of the three structural segments in the embodiment.

[0024] Figure 4 is a schematic diagram of the AA section of Figure 1.

[0025] Figure 5 is a schematic diagram of the BB section of Figure 1.

[0026] Figure 6 is an enlarged schematic diagram of the feather tip structure unit in this embodiment.

[0027] Figure 7 is an enlarged schematic diagram of two adjacent feather tip structural units in this embodiment.

[0028] Figure 8 is a schematic diagram of the left view of Figure 7.

[0029] Figure 9 is a schematic diagram of the serration tip side of Figure 7.

[0030] Figure 10 is a schematic diagram of the fitting curve of the side of the serration tip.

[0031] In the diagram, 1 is the leaf root structure segment; 2 is the leaf mid-section structure segment; 3 is the leaf tip structure segment; 4 is the feather tip structure unit; 5 is the groove; 6 is the Y-shaped guide slot; and 7 is the serrated tip. Detailed Implementation

[0032] The following are specific embodiments of the present invention, and the technical solution of the present invention will be further described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments, and the following embodiments do not limit the invention covered by the claims. Furthermore, not all combinations of the features described in the embodiments are necessary for the inventive solution.

[0033] The principles and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0034] Example 1

[0035] "Owl" usually refers to a nocturnal bird of prey, namely the owl. Owls are a type of bird known for their distinctive appearance and adaptation to nocturnal life. Owls typically have flat faces, large, round eyes, sharp talons, and the ability to fly silently. Due to their nocturnal activity, owls' feathers are usually quite soft, which reduces wing noise during flight, making it easier for them to approach their prey.

[0036] "Owl wings" refers to the wings of an owl. Owl wings are typically covered in soft feathers, which reduce wing noise during flight. This is crucial for owls hunting at night, making it easier to approach prey. Additionally, the feathers on an owl's wings are usually large and well-suited for flight, allowing them to maintain stability while searching for food or flying.

[0037] The aerodynamic effects of owl wings during flight are a scientific field. Studying owl-wing aerodynamics also helps in understanding the flight principles of other flying animals, thus providing inspiration for engineering design and aircraft development. Aircraft design can draw inspiration from flying animals in nature to improve flight efficiency and reduce noise. Owl-wing aerodynamics research has the potential to provide valuable insights in this regard.

[0038] Engineering bionics, as an interdisciplinary field, is dedicated to solving engineering problems using biological characteristics and structures. The silent flight capabilities of owls offer new insights for wind turbine design. Adopting suitable owl-shaped airfoils in wind turbine design can effectively improve aerodynamic performance and reduce aerodynamic noise. The coupling design of a Y-groove and a serrated trailing edge at the wind turbine's trailing edge can guide and cut airflow across the blade surface, thereby reducing aerodynamic noise. Therefore, coupling owl-shaped airfoils with the structure is a practical and feasible wind turbine design approach.

[0039] To address this, as shown in Figures 1, 2, and 3, a wind turbine blade is designed, divided into multiple structural segments from the blade root to the blade tip. These segments have different airfoils, and the airfoil cross-sections of each segment from the root to the tip are identical in shape to the airfoil cross-sections sequentially taken along the wingspan. This ensures that each structural segment has the same airfoil structure as the corresponding part of an owl's wing. By coupling airfoils with different span-ratio cross-sections of owl wings with multiple structures in the design, the pressure difference between the upper and lower surfaces of the wind turbine blade is increased, enhancing its work capacity. This allows the structural segment to achieve the same noise reduction effect as that part of the owl's wing airfoil. Since each structural segment uses the same cross-section airfoil, manufacturing is easy and cost-effective. Suitable cross-section airfoils can be selected for each structural segment, thus achieving a comprehensive optimization of noise reduction and cost. The owl wing airfoil extraction method involves reverse modeling of the owl's wing through reverse reconstruction engineering, extracting the coordinate points of cross-sections with different span-ratios, and then smoothing them using a fitting function.

[0040] Traditional wind turbine noise reduction methods often negatively impact aerodynamic performance by reducing aerodynamic noise. Replacing traditional methods with owl-shaped airfoils during the wind turbine design process can effectively improve the pressure difference between the upper and lower surfaces of the blades, increase their work capacity, and enhance their aerodynamic performance.

[0041] The blade is divided into three structural segments from the root to the tip: root segment 11, mid-section segment 22, and tip segment 33. These three segments are located in the 0-35%, 35-70%, and 70-100% range of the blade length, respectively. Specifically, the root segment, which covers 0-35% of the length from the root to the tip, uses a 40% owl-shaped airfoil; the mid-section segment, which covers 35-70% of the length from the root to the tip, uses a 50% owl-shaped airfoil; and the tip segment, which covers 70-100% of the length from the root to the tip, uses a 60% owl-shaped airfoil.

[0042] The blade root section is the stress concentration area of ​​the wind turbine blade. Using a relatively thicker owl-shaped 40% cross-section airfoil effectively enhances the structural strength of the wind turbine and meets the operating requirements under various conditions. The blade mid-section is the main power-generating area of ​​the wind turbine, employing an owl-shaped 50% cross-section airfoil with optimal aerodynamic performance. By altering the pressure difference between the upper and lower surfaces of the blade, the wind turbine's work capacity is effectively improved. The blade tip section is the area with the highest linear velocity of the wind turbine blade. Using an owl-shaped 60% cross-section airfoil with the best acoustic performance effectively reduces the wind turbine's aerodynamic noise. The pressure difference between the upper and lower surfaces of the blade is one of the key factors in generating lift during wind turbine operation. Utilizing this pressure difference can increase the wind turbine's lift, thereby increasing its lift capacity and improving the lift performance of aerodynamic devices such as aircraft and wind turbines.

[0043] Setting the proportions of each area in this way can achieve better noise reduction performance and structural strength, while also being beneficial for production and cost control.

[0044] The three airfoil sections taken sequentially along the owl's wing span are equidistant, which allows the three structural sections to have a more consistent airfoil structure with the owl's wing.

[0045] The three airfoil sections are located at 40%, 50%, and 60% of the owl's wing span, respectively. The airfoil sections at these positions further utilize the application of wind turbine blades, thereby enabling the wind turbine blades to have better noise reduction performance and structural strength.

[0046] The trailing edge of the blade is provided with feather tip structure units 4 that mimic the trailing edge feathers of an owl's wing, so that the trailing edge of the blade has a structure similar to the trailing edge feathers of an owl's wing, which is beneficial to the aerodynamic noise reduction of the blade.

[0047] As shown in Figures 4, 5, and 6, there is a groove 5 between adjacent feather tip structural units 4. The groove 5 guides the airflow to delay the detachment position of the detachment vortex on the blade surface, thereby facilitating the work done by the blade.

[0048] As shown in Figures 7, 8, and 9, the end of the groove 5 facing the leading edge of the blade has a Y-shaped guide slot 6 that is inclined relative to the blade surface, so that the blade surface and the groove 5 have an inclined transition, which is beneficial for guiding the airflow.

[0049] The tail end of the feather tip structure unit 4 is a coupled structure with a serrated tip 7, a groove 5, and a serrated trailing edge. By guiding and cutting the airflow, it delays the detachment position of the detachment vortex on the blade surface and cuts the detachment vortex to reduce blade aerodynamic noise. The coupling structure is achieved by slotting at the trailing edge of the blade, with two structural units mating together to form the groove 5 tail end, and a serrated trailing edge is added to the groove tail end.

[0050] A serrated trailing edge is a common aerodynamic trailing edge design used to improve aerodynamic performance. It is typically applied to aircraft wings, wind turbine blades, and other aerodynamic devices. This serrated design offers several aerodynamic effects and advantages. For wind turbines, a serrated trailing edge reduces the pressure gradient at the blade trailing edge, decreasing the likelihood of vortex shedding. This helps delay fluid separation and vortex shedding, improving aerodynamic efficiency. Because the serrated trailing edge reduces the risk of fluid separation and vortex shedding, it reduces turbulence generation, thereby reducing the noise level of the wind turbine or aircraft. A serrated trailing edge also helps increase aerodynamic lift, thus increasing the lift performance of the aircraft or wind turbine. This is valuable in applications requiring high lift. Furthermore, the serrated trailing edge design can alter the aerodynamic flow field at the trailing edge, potentially positively impacting the stability of the aircraft or wind turbine.

[0051] It is important to note that the specific design and application of serrated trailing edges need to comprehensively consider factors such as the fan's operating conditions, performance requirements, and noise limits. While serrated trailing edges can offer advantages in certain situations, practical applications may require theoretical analysis, numerical simulation, and experimental verification to determine whether they are suitable for specific applications.

[0052] Shedding vortices typically increase drag on aircraft or turbine blades, affecting efficiency and even causing vibration and noise. Choosing suitable airfoils can reduce the formation of shedding vortices. Some airfoils can reduce the relative position of the shedding point, thereby reducing the generation of shedding vortices. Moderately increasing the roughness of the airfoil surface can alter the flow structure and mitigate the occurrence of shedding vortices. Optimizing the aerodynamic shape of aircraft or turbine blades through flow field numerical simulation and experiments can further reduce the generation of shedding vortices.

[0053] By adopting a Y-shaped groove coupled with a serrated trailing edge, the airflow on the blade surface can be effectively guided and the location of the shedding vortex on the blade surface can be delayed. The serrated structure can further cut the guided airflow, effectively reducing the size of the shedding vortex, thereby further reducing the aerodynamic noise of the blade.

[0054] Airflow cutting noise reduction is a common noise reduction technique used in aerodynamic devices such as wind turbine blades. It aims to reduce noise generation by altering the flow characteristics of airflow. The core idea of ​​this method is to influence the generation of eddies and turbulence by changing the speed, direction, or distribution of airflow, thereby reducing noise levels. Changing the shape and structure of the blade surface reduces the likelihood of turbulence and eddies being generated on the blade surface, thus reducing noise.

[0055] The feather tip structures on different structural segments are of different sizes. The feather tip structure units 4 on the structural segments decrease in size sequentially from the leaf root to the leaf tip, so that the feather tip structure unit 4 matches the aerodynamic structure of the airfoil of its corresponding structural segment, thereby obtaining a biomimetic structure that is closer to an owl's wing.

[0056] α is the length of the Y-shaped guide groove, β is the length of the feather tip structural unit, γ is the width of the feather tip structural unit, δ is the length of the V-shaped portion of the Y-shaped guide groove, ε is the length of the serrated tip of the feather tip structural unit, θ is the included angle of the V-shaped portion of the Y-shaped guide groove, ω is the inclination angle of the Y-shaped guide groove relative to the blade surface, and υ is the included angle between adjacent serrated tips. The three structural segments are the leaf root structural segment, the leaf mid-segment structural segment, and the leaf tip structural segment. In the leaf root structural segment, the above parameters are: α = 0.115 mm, β = 0.185 mm. m, γ = 0.1167 mm, δ = 0.0621 mm, ε = 0.0732 mm, θ = 135°, ω = 35°, υ = 146°; In the mid-leaf segment, the above parameters are: α = 0.12 mm, β = 0.18 mm, γ = 0.0875 mm, δ = 0.0636 mm, ε = 0.072 mm, θ = 120°, ω = 35°, υ = 137°; In the leaf tip segment, the above parameters are: α = 0.14 mm, β = 0.16 mm, γ = 0.051 mm, δ = 0.073 mm, ε = 0.0672 mm, θ = 90°, ω = 30°, υ = 120°. These structural parameters satisfy the following table:

[0057] Airfoil section location α / mm β / mm γ / mm δ / mm ε / mm θ / ° ω / ° υ / ° 40% section at the blade root: 0.115c 0.185c 0.1167l 0.0621c 0.0732c 135 35 146 50% section at the blade mid-section: 0.12c 0.18c 0.0875l 0.0636c 0.072c 120 35 137 60% section at the blade tip: 0.14c 0.16c 0.05l 0.073c 0.0672c 90 30 120 surface

[0058] The blade structure designed using the above parameter values ​​can have good noise reduction performance.

[0059] As shown in Figure 10, the curve equation of the contour of half the edge of the sawtooth tip is:

[0060] y = a1x + a2x 2 +a3x 3 +c1;

[0061] in,

[0062] a1 = -3.52291 ± 0.25801,

[0063] a2 = 0.04044 ± 0.00633,

[0064] a3=-2.20532E-4±4.10959E-5,

[0065] c1 = 170.67234 ± 2.1376

[0066] y is the length of the saw tooth tip.

[0067] x represents the length and width of the serration tip.

[0068] The above curve equation is designed to further reduce the aerodynamic noise of the blades.

[0069] The noise reduction principle of owl wings involves the mechanisms by which owls reduce flight noise. This principle is mainly related to the structure of the owl's wings, its flight attitude, and the aerodynamic performance of its wings. The relatively soft feathers on an owl's wings, compared to the stiff wing feathers of some other birds, are less prone to generating sharp air turbulence and flutter, thus reducing flight noise. The airfoil structure of the owl's wings results in lower aerodynamic noise during flight. This airfoil may allow for better control of airflow, reducing the generation of turbulence and eddies. Owls typically fly at low speeds and with a relatively flat flight attitude, which helps reduce airflow noise. The owl's feathers may possess special structures that reduce flutter or other noise-generating mechanisms.

[0070] The owl-wing biomimetic approach is a method that draws inspiration from the wing structure and flight mechanism of owls, applying it to engineering design and technological innovation. It involves studying the structure of the owl's wing, including the characteristics of its feathers, wing shape, and wing bone construction. Detailed analysis of the owl's structure reveals its flexibility, lightweight nature, and noise reduction characteristics. Numerical simulations or wind tunnel experiments are used to analyze the aerodynamic performance of the owl's wing during flight. This includes aerodynamic forces, lift, drag, and turbulence characteristics. Simulation and experiments reveal the owl's flight mechanism. Inspiration from the owl's wing is applied to aircraft design to improve flight stability and reduce noise, particularly optimizing for low-speed and quiet flight. The design and improvements are then tailored to application requirements. The designed biomimetic system is experimentally validated, verifying its performance in simulated or real-world environments. Adjustments and improvements are made based on the experimental results.

[0071] The blades in this embodiment are suitable for axial flow fans, a common type of wind-powered machinery used to generate airflow or wind. Its working principle is that the rotation of the blades causes air to flow in the axial direction, thereby generating wind. The main characteristic of axial flow fans is that the airflow maintains an axial direction when entering and exiting the fan, unlike centrifugal fans which produce significant radial flow.

[0072] Axial flow fans generate noise during operation, primarily from airflow, blade vibration, motor operation, and interaction with the surrounding environment. The noise level of an axial flow fan is affected by various factors, including fan size, rotational speed, design, installation location, and operating environment. Improving the shape of the fan blades to reduce the interaction between the blades and the air can reduce noise.

[0073] Optimizing airfoils is one of the important methods to improve the aerodynamic performance of wind turbine blades. Through reasonable airfoil design and optimization, wind resistance can be reduced, lift increased, and noise reduced, thereby improving the efficiency and performance of the wind turbine. Choosing an airfoil suitable for a specific application is crucial. Different airfoils perform differently at different wind speeds and wind turbine sizes. Selecting a suitable airfoil can improve the aerodynamic performance of the wind turbine to a certain extent. By optimizing parameters such as blade geometry, twist angle, and airfoil curvature, the streamline shape of the blade can be improved, drag reduced, and lift distribution enhanced. Some airfoil designs can reduce noise during wind turbine operation. Design features such as reducing turbulence and avoiding sharp edges can lower noise levels. Using flow field control techniques, such as blowing or sucking, flow can be manipulated on the blade surface, changing the separation point, reducing aerodynamic drag, and improving aerodynamic performance.

[0074] Cutting shedding vortices on the blade surface is one method to reduce wind turbine noise and improve aerodynamic efficiency. Shedding vortices are turbulent eddies that form on the surface of wind turbine blades, leading to energy loss and noise generation. By designing the surface shape and structure of the blades, the formation of shedding vortices can be reduced, thus improving the aerodynamic performance of the wind turbine. Designing cut slits, grooves, or small holes at the leading and trailing edges of the blades can alter the flow separation point and vortex formation, reducing the generation of shedding vortices. Appropriate surface smoothness can reduce turbulence formation and decrease the occurrence of shedding vortices. Moderate blade twisting and bending can alter the aerodynamic characteristics of the blades, reducing shedding vortices and improving the aerodynamic efficiency of the wind turbine.

[0075] Delaying the shedding of the boundary layer on the surface of wind turbine blades by guiding airflow to cut the airflow is a method to reduce wind turbine noise and improve aerodynamic efficiency. Boundary layer shedding refers to the gradual loss of adhesion and the formation of a turbulent layer as airflow passes over an object's surface, which increases the aerodynamic drag and noise of the wind turbine. By guiding the airflow, the flow characteristics of the boundary layer can be altered, reducing the occurrence of shedding and thus improving wind turbine performance.

[0076] Although this document uses a number of technical terms, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention. The order of actions, steps, etc., in the apparatus and methods shown in the specification and drawings can be implemented in any order unless otherwise expressly specified, and provided that the output of a preceding process is not used in a subsequent process. Similar sequential terms used for descriptive convenience (e.g., "firstly," "next," "secondly," "again," "then," etc.) do not imply that the actions must be performed in such an order.

[0077] Those skilled in the art will understand that all directional references (e.g., above, below, up, up, down, down, top, bottom, left, right, vertical, horizontal, etc.) are used descriptively in the drawings to aid the reader's understanding and do not imply (e.g., a limitation on the scope of the invention as defined by the appended claims) a limitation on the scope of the invention as defined by the appended claims. They are merely for the purpose of facilitating the description of this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation. The directional terms "inside" and "outside" refer to inside or outside relative to the outline of the respective component itself.

[0078] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0079] Additionally, some vague terms (e.g., substantially, certain, generally, etc.) may refer to slight inaccuracies or minor deviations in conditions, quantities, values, or dimensions, some of which are within manufacturing tolerances or limits. It should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components; unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application.

[0080] The specific embodiments described herein are merely illustrative examples illustrating the spirit of the invention. Those skilled in the art can make various modifications or additions to the described embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A wind turbine blade, characterized in that, The blade is divided into multiple structural segments from the root to the tip, each segment having a different airfoil. The airfoil cross-sections of these segments from root to tip are identical in shape to the airfoil cross-sections sequentially taken along the owl's wingspan. The blade is further divided into three structural segments, located at 0-35%, 35-70%, and 70-100% of the blade length, respectively. The trailing edge of the blade is provided with feather tip structures, mimicking the trailing edge of an owl's wings, arranged along the blade's length. Adjacent feather tip structures have grooves between them. The three airfoil cross-sections are located sequentially at 40%, 50%, and 60% of the owl's wingspan. The end of the groove facing the leading edge of the blade has a Y-shaped guide slot inclined relative to the blade surface. The tail end of each feather tip structure unit has a serrated tip.

2. The wind turbine blade according to claim 1, characterized in that, The distance between the three airfoil sections taken sequentially along the owl's wingspan is equal.

3. The wind turbine blade according to claim 1, characterized in that, α is the length of the Y-shaped guide groove, β is the length of the feather tip structural unit, γ is the width of the feather tip structural unit, δ is the length of the V-shaped portion of the Y-shaped guide groove, ε is the length of the serrated tip of the feather tip structural unit, θ is the included angle of the V-shaped portion of the Y-shaped guide groove, ω is the inclination angle of the Y-shaped guide groove relative to the blade surface, and υ is the included angle between adjacent serrated tips. The three structural segments are the leaf root structural segment, the leaf mid-segment structural segment, and the leaf tip structural segment. In the leaf root structural segment, the above parameters are: α = 0.115 mm, β = 0.185 mm. For the leaf midsection, the parameters are: α=0.12mm, β=0.18mm, γ=0.0875mm, δ=0.0636mm, ε=0.072mm, θ=120°, ω=35°, υ=137°. For the leaf tip, the parameters are: α=0.14mm, β=0.16mm, γ=0.051mm, δ=0.073mm, ε=0.0672mm, θ=90°, ω=30°, υ=120°.

4. The wind turbine blade according to claim 1, characterized in that, The curve equation of the contour of half an edge of the sawtooth tip is: ;in, ， ， ， y is the length of the saw tip, and x is the length and width of the saw tip.

5. The wind turbine blade according to claim 1, characterized in that, The size of the feather tip structure on different structural units is different, and the feather tip structure units on the structural segment decrease in size sequentially from the leaf root to the leaf tip.

6. A fan, characterized in that, Includes the wind turbine blades as described in any one of claims 1 to 5.

Images