CN116838643A - Fan blade and fan - Google Patents

Abstract

The application discloses a fan blade and a fan, wherein the fan blade is divided into a plurality of different structural sections from a blade root to a blade tip of the blade, the different structural sections have different wing profiles, and the wing profile section of the different structural sections from the blade root to the blade tip is the same as the wing profile section shape which is sequentially cut in the wingspan direction. The application segments the blade in the length direction, so that different segments of the blade correspond to different wing sections of the owl to perform segmented bionic, the bionic difficulty is simplified, the pressure difference between the upper surface and the lower surface of the fan blade is increased, the acting capability of the fan blade is improved, and meanwhile, the aerodynamic noise is reduced by utilizing the wing section type principle of the owl. The wing sections have the same wing section structure as the wing section structure of the corresponding part of the owl wing, so that the structural section has the same noise reduction effect as the wing section of the owl wing.

Description

Fan blade and fan

Technical Field

The application relates to the technical field of fans, in particular to a fan blade and a fan.

Background

Along with the development of technology, the application occasions of the axial flow fan are gradually increased, and the pneumatic noise problem of the fan is also emphasized, and the pneumatic performance of the fan is often influenced by the traditional noise reduction means, such as the addition of a sawtooth tail edge, a wavy front edge and the like, although the pneumatic noise of the blade can be effectively reduced.

Engineering bionics is used as a crossing subject and aims to solve engineering problems by adopting biological characteristics and structures. The ability to silence the flight in class provides a new idea for fan design. Proper owl wing shapes are adopted for fan design, so that the pneumatic performance of the fan can be effectively improved, and the pneumatic noise of the fan can be reduced. However, the owl wing-shaped section has a complex overall structure and is of a feather structure, and is limited by production cost and materials, so that the fan blade cannot be manufactured into a structure which is completely the same as that of the owl wing-shaped section, and how to manufacture the blade which can be practically used by utilizing the noise reduction principle of the owl wing-shaped section in a bionic mode is a technical problem to be solved in the industry.

Disclosure of Invention

In order to solve the practical problem of owl wing-shaped bionic blades, the application provides the segmentation of the blades in the length direction, so that different segments of the blades correspond to wing-shaped parts of owl, the segmented bionic is carried out, the bionic difficulty is simplified, and meanwhile, the pneumatic noise is reduced by utilizing the wing-shaped principle of owl.

The technical scheme includes that the fan blade is designed, the fan blade is divided into a plurality of different structural sections from a blade root to a blade tip of the fan blade, the different structural sections have different wing profiles, and the wing profile sections of the different structural sections from the blade root to the blade tip are identical to the wing profile section shapes which are sequentially cut in the wing span direction.

In certain embodiments, the blade root to blade tip is divided into three structural sections, and the three structural sections from the blade root to blade tip are located in the 0-35% area, 35% -70% area, and 70% -100% area of the blade length, respectively.

In certain embodiments, the three airfoil sections taken sequentially in the owl spanwise direction are equidistant.

In certain embodiments, three of the airfoil sections are located 40%, 50%, 60% in turn along the wing span direction of the owl.

In some embodiments, the tail edge of the blade is provided with feather end structural units of the tail edge feather end of the bionic owl arranged along the length direction of the blade.

In certain embodiments, grooves are provided between adjacent ones of the feather end structural elements.

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

In certain embodiments, the feather end structural element is aft-ended with a saw tooth tip.

In some embodiments, α is the length of the Y-shaped guiding slot, β is the length of the feather end structural unit, γ is the width of the feather end structural unit, δ is the length of the V-shaped portion of the Y-shaped guiding slot, ε is the length of the sawtooth tip of the feather end structural unit, θ is the angle of the V-shaped portion of the Y-shaped guiding slot, ω is the angle of inclination of the Y-shaped guiding slot with respect to the blade surface, V is the angle of the adjacent sawtooth tip, and three of the structural sections are respectively the blade root structural section, the blade middle structural section, and the blade tip structural section, where the parameters are respectively: α=0.115 mm, β=0.185 mm, γ=0.1167 mm, δ=0.0621 mm, ε= 0.0732mm, θ=135°, ω=35°, v=146°; the parameters of the structural section in the leaf are respectively as follows: α=0.12 mm, β=0.18 mm, γ=0.0875 mm, δ= 0.0636mm, ε=0.072 mm, θ=120°, ω=35°, v=137°; the parameters in the blade tip structural section are respectively as follows: α=0.14 mm, β=0.16 mm, γ=0.05 l mm, δ=0.073 mm, ε= 0.0672mm, θ=90°, ω=30°, v=120°.

In certain embodiments, the curve equation for the profile of the half edge of the serration tip is: y=a ₁ x+a ₂ x ² +a ₃ x ³ +c ₁ The method comprises the steps of carrying out a first treatment on the surface of the Wherein a is ₁ ＝-3.52291±0.25801，a ₂ ＝0.04044±0.00633，a ₃ ＝-2.20532E-4±4.10959E-5，c ₁ = 170.67234 ±2.1376, y is the length of the serration tip, and x is the length width of the serration tip.

In certain embodiments, the feather end structure on the structural element is of different sizes, decreasing in sequence from root to tip.

The fan comprises the fan blade.

Compared with the prior art, the application has the following beneficial effects:

the application segments the blade in the length direction, so that different segments of the blade correspond to different wing sections of the owl to perform segmented bionic, the bionic difficulty is simplified, the pressure difference between the upper surface and the lower surface of the fan blade is increased, the acting capability of the fan blade is improved, and meanwhile, the aerodynamic noise is reduced by utilizing the wing section type principle of the owl. The wing section structure of each structural section is the same as the wing section structure of the corresponding part of the owl wing, so that the structural section has the same noise reduction effect as the wing section of the owl wing.

According to the application, the Y-shaped groove and the saw-tooth tail edge are adopted at the tail edge of the fan blade, and the shedding position of the shedding vortex on the surface of the blade is delayed and the shedding vortex is cut in a mode of guiding airflow and cutting airflow so as to reduce the pneumatic noise of the blade. The design thought of the coupling structure is that grooving design is carried out at the tail edge of the blade, Y-shaped groove tail ends are formed through the two-by-two matching of the structural units, meanwhile, the sawtooth tail edges are additionally arranged at the groove tail ends, and the sawtooth tail edge molded lines are optimized according to the water drop molded lines so as to further reduce the pneumatic noise of the fan.

Drawings

The present application will now be described in detail with reference to specific embodiments and drawings, which are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the application. The drawings illustrate generally, by way of example and not limitation, embodiments discussed herein. Wherein:

FIG. 1 is a schematic view of an embodiment blade.

FIG. 2 is a schematic diagram of a blower of an embodiment.

Fig. 3 is a comparative schematic diagram of the appearance of three structural sections of an embodiment.

Fig. 4 is a schematic view of section A-A of fig. 1.

Fig. 5 is a schematic view of section B-B of fig. 1.

Fig. 6 is an enlarged schematic view at the feather end structural element of the present embodiment.

Fig. 7 is an enlarged schematic view at two adjacent feather end structural elements of the present embodiment.

Fig. 8 is a left side schematic view of fig. 7.

Fig. 9 is a schematic view of the serration tip side of fig. 7.

Fig. 10 is a schematic of a sawtooth tip side fitting curve.

In the figure, 1, a blade root structural section; 2. a leaf-in-structure segment; 3. a blade tip structural section; 4. a feather end structural unit; 5. a groove; 6. y-shaped guide notch; 7. saw tooth tips.

Detailed Description

The following are specific examples of the present application and the technical solutions of the present application will be further described with reference to the accompanying drawings, but the present application is not limited to these examples, and the following embodiments do not limit the applications according to the claims. Furthermore, all combinations of features described in the embodiments are not necessarily essential to the inventive solution.

The principles and structures of the present application are described in detail below with reference to the drawings and the examples.

Example 1

"owl" generally refers to a bird with a nighttime habit of motion, namely a owl. Owl is a type of bird that is known for its special appearance and habit of adapting to night life. Cat owls generally have a flat face, large round eyes, sharp paws, and ability to fly silently. Because of night activities, the feathers of the owl are generally softer, which can reduce wing noise during flight, making it easier to access the prey.

"owl wing" refers to the wing of a owl. Wings of the owl typically present soft feathers so that they reduce wing noise during flight, which is important for the owl to predate at night and to gain easier access to the prey. In addition, feathers on the wings of the owl are typically large and suitable for flying, allowing them to remain stable while looking for food or flying.

Is a scientific field of aerodynamic effects to which the wings of (a) are subjected during flight. The research of owl wing aerodynamics is also helpful for understanding the flight principle of other flying animals, thereby providing inspiration in engineering design and aircraft development. The design of the aircraft can be used for referencing flying animals in nature so as to improve the flying efficiency and reduce the noise. Wing aerodynamics studies have the potential to be borrowed in this respect.

Engineering bionics is used as a crossing subject and aims to solve engineering problems by adopting biological characteristics and structures. The ability to silence the flight in class provides a new idea for fan design. Proper owl wing shapes are adopted for fan design, so that the pneumatic performance of the fan can be effectively improved, and the pneumatic noise of the fan can be reduced. The coupling design of the Y-shaped groove and the saw-tooth tail edge is carried out at the tail edge of the fan, so that the airflow on the surface of the blade can be guided and cut, and the pneumatic noise of the blade is reduced. Therefore, the owl wing section and the structure are coupled, and the design is a feasible fan design thought.

For this purpose, as shown in fig. 1, 2 and 3, a fan blade is designed, wherein the blade root to the blade tip of the blade are divided into a plurality of different structural sections, the different structural sections have different wing profiles, and the wing profile section of the different structural sections from the blade root to the blade tip is identical to the wing profile section shape which is sequentially cut in the wing span direction. Therefore, each structural section has the same wing shape structure as the wing shape structure of the corresponding part of the owl wing, the wing shape with the owl wing extending direction being larger than that of the wing shape with different sections is adopted for coupling design with a plurality of structures, so that the pressure difference between the upper surface and the lower surface of the fan blade is increased, the acting capability of the fan blade is improved, the structural section has the same noise reduction effect as the wing shape of the part of the owl wing, and the structural sections have the same section wing shape, so that the manufacturing is easy, the cost is low, the section wing shape suitable for each structural section can be selected, and the noise reduction and the cost are comprehensively optimized. The wing airfoil extraction method is to reversely model the wing of the owl by reverse reconstruction engineering, extract coordinate points with different spanwise specific cross sections and carry out light smoothing treatment on the coordinate points by adopting a fitting function.

Aiming at the problems that the pneumatic performance of a fan is influenced when the pneumatic noise is reduced by the traditional fan noise reduction means. In the design process of the fan, the owl wing type wing section is adopted for replacement, so that the pressure difference between the upper surface and the lower surface of the blade can be effectively improved, the acting capacity of the blade is increased, and the aerodynamic performance of the blade is improved.

The blade root to blade tip is divided into three structural sections, namely a blade root structural section 11, a blade middle structural section 22 and a blade tip structural section 33, wherein the three structural sections from the blade root to the blade tip are respectively positioned in 0-35% of the length of the blade, 35% -70% of the length of the blade and 70% -100% of the length of the blade, namely the blade root structural section is the length of 0-35% of the length of the blade root to the blade tip, a wing-in-wing 40% section wing type is adopted, the blade middle structural section is the length of 35% -70% of the length of the blade root to the blade tip, a wing-in-wing 50% section wing type is adopted, the blade tip structural section is the length of 70% -100% of the length of the blade root to the blade tip, and a wing-in-wing 60% section wing type is adopted.

The blade root structural section area is a stress concentration area of a fan blade of the fan, 40% section wing type of the low-wing with relatively large thickness is adopted, the structural strength of the fan can be effectively enhanced, the use requirements of the fan under various working conditions are met, the in-blade structural section area is a main working area of the fan, 50% section wing type of the low-wing with optimal aerodynamic performance is adopted, the working capacity of the fan is effectively improved by changing the pressure difference between the upper surface and the lower surface of the blade, the blade tip structural section area is the area with the maximum linear speed of the fan blade of the fan, and 60% section wing type of the low-wing with the best acoustic performance is adopted, so that the aerodynamic noise of the fan can be effectively reduced. The pressure difference between the upper surface and the lower surface of the blade is one of the key factors for generating lift force when the fan works. The lift force of the fan can be improved by utilizing the pressure difference between the upper surface and the lower surface of the blade, so that the lift force of the fan is increased, and the lift force performance of aerodynamic devices such as an aircraft, a wind turbine and the like is improved.

The proportion of each region can obtain better noise reduction performance and structural strength, and is beneficial to production and control of cost.

The three airfoil sections taken sequentially along the wingspan direction of the owl have equal distances, so that the three structural sections and the owl have more consistent airfoil structures.

The three airfoil sections are sequentially positioned at 40%, 50% and 60% along the wing span direction of the owl, and the section airfoil sections of the owl wings at the positions further utilize the application of the fan blade, so that the fan blade has good noise reduction performance and structural strength.

The tail edge of the blade is provided with the feather end structural units 4 of the feather ends of the tail edges of the bionic wings along the length direction of the blade, so that the tail edge of the blade has a structure similar to the feather ends of the tail edges of the wing, and the pneumatic noise reduction of the blade is facilitated.

As shown in fig. 4, 5 and 6, grooves 5 are formed between adjacent feather end structural units 4. The grooves 5 are beneficial to acting of the blades by guiding the air flow to delay the falling position of the falling vortex on the surfaces of the blades.

The end of the groove 5 facing the leading edge of the blade, as shown in figures 7, 8 and 9, has a Y-shaped guiding slot 6 inclined relative to the blade surface, so that the blade surface has an inclined transition with the groove 5, facilitating the guiding of the air flow.

The tail end of the feather end structure unit 4 is provided with a sawtooth tip 7, and the groove 5 is in a coupling structure with the sawtooth tail edge, so that the shedding position of the shedding vortex on the surface of the blade is delayed by guiding airflow and cutting airflow, and the shedding vortex is cut to reduce the pneumatic noise of the blade. The coupling structure is formed by carrying out slotting design on the tail edge of the blade and matching the structural units in pairs, so that the tail end of the groove 5 is formed, and meanwhile, the tail end of the groove is additionally provided with a sawtooth tail edge.

Blade serrated trailing edges are a common aerodynamic trailing edge design, which is a blade tail design for improved aerodynamic performance, commonly used in aircraft wings, wind turbine blades, or other aerodynamic devices. The zigzag design can bring about some pneumatic effects and advantages, and the zigzag trailing edge of the fan can reduce the pressure gradient at the tail part of the blade and reduce the possibility of vortex shedding. This helps to retard fluid separation and vortex shedding, improving aerodynamic efficiency. The noise level of the fan or aircraft can be reduced by reducing turbulence generation due to the reduced risk of fluid separation and vortex shedding by the serrated trailing edge. The serrated trailing edge helps to improve aerodynamic lift, thereby increasing the lift performance of the aircraft or wind turbine. This is valuable in some applications where a large lift is required. : the design of the serrated trailing edge may alter the aerodynamic flow field of the tail, potentially positively affecting the stability of the aircraft or wind turbine.

It should be noted that the specific design and application of the saw tooth trailing edge needs to comprehensively consider the factors such as the working condition, the performance requirement, the noise limitation and the like of the fan. While the serrated trailing edge may be advantageous in some situations, in practice, theoretical analysis, numerical modeling, and experimental verification may be required to determine whether the serrated trailing edge is suitable for a particular application.

Shedding vortices often increase drag on the aircraft or blades, affect efficiency, and even lead to vibration and noise. The airfoil is selected to reduce the formation of vortex shedding. Certain airfoils can reduce the relative position of the shedding points, thereby reducing the generation of shedding vortices. The roughness of the wing surface can be moderately increased, the flowing structure can be changed, and the occurrence of falling vortex is slowed down. Aerodynamic profiles of aircraft or turbine blades are optimized through flow field numerical simulation and experiments to reduce the generation of shedding vortices.

The Y-shaped groove and the saw tooth trailing edge coupling structure are adopted, so that airflow on the surface of the blade can be effectively guided, the shedding vortex shedding position on the surface of the blade is delayed, the saw tooth structure can cut the guided airflow again, the size of the shedding vortex is effectively reduced, and the pneumatic noise of the blade is further reduced.

Air flow cutting noise reduction is a noise reduction technology commonly used for aerodynamic devices such as wind blades, and aims to reduce noise generation by changing the flow characteristics of air flow. The core idea of this approach is to influence the generation of vortices and turbulence by changing the speed, direction or distribution of the air flow, thereby reducing the noise level. Changing the shape and structure of the blade surface reduces the likelihood of turbulence and eddies of the airflow at the blade surface, thereby reducing noise.

The sizes of the feather end structures on the different structural sections are different, and the feather end structural units 4 on the structural sections are sequentially reduced from the blade root to the blade tip, so that the feather end structural units 4 are matched with the pneumatic structures of the wing profiles of the corresponding structural sections, and a bionic structure which is closer to the wing is obtained.

Alpha is the length of a Y-shaped guiding notch, beta is the length of a feather end structural unit, gamma is the width of the feather end structural unit, delta is the length of a V-shaped part of the Y-shaped guiding notch, epsilon is the length of a sawtooth tip of the feather end structural unit, theta is an included angle of the V-shaped part of the Y-shaped guiding notch, omega is the inclined angle of the Y-shaped guiding notch relative to the surface of the blade, V is the included angle of adjacent sawtooth tips, and three structural sections are respectively a blade root structural section, a blade middle structural section and a blade tip structural section, and the parameters of the blade root structural section are respectively as follows: α=0.115 mm, β=0.185 mm, γ=0.1167 mm, δ=0.0621 mm, ε= 0.0732mm, θ=135°, ω=35°, v=146°; the parameters of the structural section in the leaf are respectively as follows: α=0.12 mm, β=0.18 mm, γ=0.0875 mm, δ= 0.0636mm, ε=0.072 mm, θ=120°, ω=35°, v=137°; the parameters in the blade tip structural section are respectively as follows: α=0.14 mm, β=0.16 mm, γ=0.05 l mm, δ=0.073 mm, ε= 0.0672mm, θ=90°, ω=30°, v=120°, the above structural parameters satisfying the following table:

structural section

Airfoil section position

α/mm

β/mm

γ/mm

δ/mm

ε/mm

θ/°

ω/°

υ/°

Root of leaf

40% cross section

0.115c

0.185c

0.1167l

0.0621c

0.0732c

135

35

146

Middle part of leaf

50% cross section

0.12c

0.18c

0.0875l

0.0636c

0.072c

120

35

137

Leaf tip

60% cross section

0.14c

0.16c

0.05l

0.073c

0.0672c

90

30

120

The blade structure designed by utilizing the parameter values can have better noise reduction performance.

As shown in fig. 10, the curve equation of the profile of the half edge of the serration tip is:

y＝a ₁ x+a ₂ x ² +a ₃ x ³ +c ₁ ；

wherein,,

a ₁ ＝-3.52291±0.25801，

a ₂ ＝0.04044±0.00633，

a ₃ ＝-2.20532E-4±4.10959E-5，

c ₁ ＝170.67234±2.1376，

y is the length of the tips of the serrations,

x is the length and width of the serration tips.

The above curve equation is such that aerodynamic noise of the blade is further reduced.

The wing noise reduction principle relates to a mechanism of how the owl reduces flying noise in the flying process. This principle is mainly related to the structure of the owl wings, the flying attitude and the aerodynamic performance of the wings. Feathers on the wings of the owl are relatively soft, and sharp air turbulence and vibration are less likely to occur compared with hard wing feathers of some other birds, thereby reducing flight noise. The wing airfoil structure of (1) makes aerodynamic noise lower when flying. Such airfoils may be able to better control air flow, reducing turbulence and vortex generation. The owl usually flies at a low speed and the flying posture is gentle, which helps to reduce the air flow noise. Feathers of the wing may have special structures that reduce flutter or other noise-causing mechanisms.

The wing bionic method is a method for acquiring inspiration from a wing structure and a flight mechanism of the owl and applying the inspiration to engineering design and technical innovation. The structure of the wing of the owl is studied, including the characteristics of the feather, the shape of the wing, the structure of the wing bone and the like. By analyzing the structure of the owl wings in detail, the softness, light weight and noise reduction characteristics can be understood. And analyzing the aerodynamic performance of the wing in the flight process by using numerical simulation or wind tunnel experiments. This includes aerodynamic, lift, drag, turbulence, etc. Through simulation and experiments, the flying mechanism of the owl wing can be revealed. The teachings obtained from owl wings are applied to the design of aircraft to improve its flight stability, reduce noise, and in particular optimize for low speed and quiet flight. And (5) designing and improving according to application requirements. And carrying out experimental verification on the designed bionic system to verify the performance of the bionic system in a simulated or actual environment. And (5) adjusting and improving according to experimental results.

The blade of the present embodiment is suitable for an axial flow fan, which is a common wind power machine for generating air flow or wind. The working principle is that air flows in the axial direction through the rotation of the blades, so that wind is generated. The axial flow fan is mainly characterized in that the air flow keeps the axial flow direction when entering and exiting the fan, and does not generate obvious radial flow like a centrifugal fan.

Axial fans produce some noise during operation, mainly from air flow, blade vibration, motor operation, and interaction with the surrounding environment. The noise level of an axial flow fan can be affected by a variety of factors including the size, speed, design, installation location, operating environment, etc. of the fan. The shape of the fan blade is improved, the interaction between the blade and the air is reduced, and the noise can be reduced.

Optimizing airfoils is one of the important ways to improve the aerodynamic performance of a fan blade. Wind resistance can be reduced, lift force can be improved, noise can be reduced, and the like through reasonable airfoil design and optimization, so that the efficiency and performance of the fan are improved. The selection of airfoils suitable for a particular application is critical. Different airfoils behave differently at different wind speeds and fan sizes. The selection of a suitable airfoil can improve the aerodynamic performance of the fan to some extent. The streamline form of the blade is improved, the resistance is reduced, and the lift force distribution is improved by optimizing the geometric shape, torsion angle, airfoil curvature and other parameters of the blade. Some airfoil designs may reduce noise when the fan is running. Designs that reduce turbulence, avoid sharp edges, etc., can reduce noise levels. The flow field control technology, such as blowing or sucking, can control the flow on the surface of the blade, change the separation point, reduce the aerodynamic resistance and improve the aerodynamic performance.

Cutting blade surface desquamation vortex is one of the methods to reduce fan noise and improve aerodynamic efficiency. Shedding vortices are turbulent vortices that form on the surface of a fan blade, resulting in energy loss and noise generation. Through the design of the surface shape and the structure of the blade, the formation of falling vortex can be reduced, and the aerodynamic performance of the fan is improved. By designing cutting slits, grooves or small holes at the edge portions of the leading edge and the trailing edge of the blade, the separation point of the flow and the formation of vortex can be changed, and the generation of the shedding vortex can be reduced. Proper surface smoothness can reduce the formation of turbulence and reduce the occurrence of vortex shedding. Moderate blade twisting and bending can change the aerodynamic properties of the blade, reduce the vortex shedding and improve the aerodynamic efficiency of the fan.

The method for reducing the noise of the fan and improving the aerodynamic efficiency is that the airflow is guided to cut the airflow, and the falling off of the boundary layer on the surface of the fan blade is delayed. Boundary layer shedding refers to the gradual loss of adhesion and formation of turbulent layers of airflow as it flows over the surface of an object, which increases aerodynamic drag and noise of the fan. By guiding the air flow, the flow characteristic of the boundary layer can be changed, and the occurrence of falling off is reduced, so that the performance of the fan is improved.

Although some terms are used more herein, the possibility of using other terms is not excluded. These terms are used merely for convenience in describing and explaining the nature of the application; they are to be interpreted as any additional limitation that is not inconsistent with the spirit of the present application. The order of execution of the operations, steps, and the like in the apparatuses and methods shown in the specification and the drawings may be any order as long as the order is not particularly limited, and the output of the preceding process is not used in the following process. The use of similar ordinal terms (e.g., "first," "then," "second," "again," "then," etc.) for convenience of description does not necessarily imply that they are necessarily performed in such order.

It will be appreciated by those of ordinary skill in the art that all directional references (e.g., above, below, upward, downward, top, bottom, left, right, vertical, horizontal, etc.) are descriptive of the drawings to aid the reader in understanding, and do not denote (e.g., position, orientation, use, etc.) limitation of the scope of the application defined by the appended claims, but rather are intended to facilitate describing the application and simplifying the description, the orientation words do not indicate and imply that the device or element being referred to must have a particular orientation or be constructed and operated in a particular orientation, the orientation words "inside and outside" referring to the inside and outside of the profile of the components themselves, unless otherwise indicated.

Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Additionally, some ambiguous terms (e.g., substantially, certain, generally, etc.) may refer to slight imprecision or slight deviation of conditions, amounts, values, or dimensions, etc., some of which are within manufacturing tolerances or tolerances. It should be noted that, the terms "first," "second," and the like are used for defining the components, and are merely for convenience in distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, so they should not be construed as limiting the scope of the present application.

The specific embodiments described herein are offered by way of example only to illustrate the spirit of the application. Those skilled in the art may make various modifications or additions to the described embodiments or substitutions thereof without departing from the spirit of the application or exceeding the scope of the application as defined in the accompanying claims.

Claims (12)

1. Fan blade, characterized in that it is divided into a plurality of different structural sections from the blade root to the blade tip of the blade, different structural sections having different airfoils, the airfoil section of different structural sections from the blade root to the blade tip being the same as the airfoil section shape taken in sequence in the spanwise direction.

2. The fan blade of claim 1 wherein the blade root to blade tip is divided into three structural sections, the three structural sections from the blade root to blade tip being located in 0-35%, 35% -70% and 70% -100% of the blade length, respectively.

3. A fan blade according to claim 2, wherein the three airfoil sections taken sequentially in the wing span direction of the roll are equidistant.

4. A fan blade according to claim 3, wherein three of the airfoil sections are located 40%, 50%, 60% in succession in the wing span direction of the owl.

5. The fan blade according to claim 2, wherein the trailing edge of the blade is provided with feather end structural units of the tail edge feather ends of the bionic owl wings arranged along the length direction of the blade.

6. The fan blade of claim 5 wherein there are grooves between adjacent said feather end structural elements.

7. The fan blade of claim 6, wherein an end of the groove toward the blade leading edge has a Y-shaped guide slot that is inclined relative to the blade surface.

8. The fan blade of claim 7 wherein the tail end of the feather end structural element is serrated.

9. The fan blade of claim 8 wherein α is the length of the Y-shaped guide slot, β is the length of the feather end structural element, γ is the width of the feather end structural element, δ is the length of the V-shaped portion of the Y-shaped guide slot, ε is the length of the saw tooth tip of the feather end structural element, θ is the angle of the V-shaped portion of the Y-shaped guide slot, ω is the angle of inclination of the Y-shaped guide slot with respect to the blade surface, V is the angle of the adjacent saw tooth tip, and three of the structural sections are the blade root structural section, the blade middle structural section, and the blade tip structural section, respectively: α=0.115 mm, β=0.185 mm,

γ＝0.1167mm，δ＝0.0621mm，ε＝0.0732mm，θ＝135°，ω＝35°，υ＝146°；

the parameters of the structural section in the leaf are respectively as follows: α=0.12 mm, β=0.18 mm, γ=0.0875 mm, δ= 0.0636mm, ε=0.072 mm, θ=120°, ω=35°, v=137°; the parameters in the blade tip structural section are respectively as follows: α=0.14 mm, β=0.16 mm, γ=0.05 l mm, δ=0.073 mm, ε= 0.0672mm, θ=90°, ω=30°, v=120°.

10. The fan blade of claim 8, wherein the curve equation for the profile of the half edge of the serrated tip is: y=a ₁ x+a ₂ x ² +a ₃ x ³ +c ₁ The method comprises the steps of carrying out a first treatment on the surface of the Wherein a is ₁ ＝-3.52291±0.25801，a ₂ ＝0.04044±0.00633，a ₃ ＝-2.20532E-4±4.10959E-5，c ₁ = 170.67234 ±2.1376, y is the length of the serration tip, and x is the length width of the serration tip.

11. The fan blade of claim 5 wherein the feathered end features on different ones of the structural elements are of different sizes, the feathered end structural elements on the structural segments decreasing in sequence from blade root to blade tip.

12. A fan comprising a fan blade according to any one of claims 1 to 11.