Bionic blade

Abstract

The invention provides a bionic blade which is provided with an inner side close to a blade handle and an outer side far away from the blade handle, and the outer side of the blade is provided with a small wing extending along the outer edge of the blade; the outer side of the blade is provided with a kiss-like body connected with the outer edge of the blade, and the kiss-like body is of a streamline structure and protrudes forwards from the front end of the outer edge; the rear edge of the outer side of each blade is at least partially recessed to form a tail-imitating body. According to the technical scheme, due to the design that the small wings are additionally arranged on the outer edges of the blades, blade top gap leakage can be effectively restrained under different working conditions, and efficient and stable operation of the fan is kept; the front side of the outer edge of each blade adopts a streamline design of a bionic dolphin kiss part, the rear edge of each blade adopts a bionic whale tail structure and a horizontal fan-shaped inward-concave streamline design, and the kiss-imitated body and tail-imitated body structure can reduce the resistance during movement in fluid. Through the combination of the structures, when the blades rotate, the stability and the overall efficiency of the fan are greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of fan blades, and in particular relates to a bionic blade. Background Art

[0002] Traditional fan blades are mostly made of steel or aluminum alloy, usually with simple geometric shapes and cross-sectional shapes, such as flat, curved, twisted, etc. This simple design is easy to manufacture and install, and uses common manufacturing processes such as casting, forging, and stamping. The blades produced have a simple structure and are relatively easy to maintain and replace parts.

[0003] However, due to design and material limitations, traditional fan blades may have problems such as poor aerodynamic performance, heavy weight, low efficiency, and high noise. These problems will affect the overall performance and application scope of the fan, increase operating costs, and not meet the requirements of energy conservation and emission reduction. Summary of the invention

[0004] The purpose of the present invention is to provide a bionic blade, aiming to solve the technical problems of poor aerodynamic performance and low efficiency of traditional fan blades.

[0005] In order to achieve the above object, the present invention provides a bionic leaf having an inner side close to the petiole and an outer side far from the petiole, wherein: The outer side of the blade is provided with a small wing extending along the outer edge thereof; The outer side of the blade is provided with a kiss-shaped body connected to the outer edge thereof, the kiss-shaped body is streamlined and protrudes forward from the front end of the outer edge; The trailing edge of the outer side of the blade is at least partially concave to form a tail-like shape.

[0006] Optionally, the winglet is divided into a lower winglet part and an upper winglet part relative to the outer edge of the blade, and the height of the lower winglet from its front end to its rear end first gradually increases and then gradually decreases, and the height of the upper winglet from its front end to its rear end first gradually increases and then gradually decreases.

[0007] Optionally, the lower portion of the winglet reaches a maximum h at a position where its length l1 1max The upper part of the winglet reaches its highest point h at the position of its length l2 2max , the winglet reaches its highest H at the position of its length l3 max ; Wherein, the total length of the winglet is L, 1 / 3L≦l1≦2 / 3L, 2 / 3L≦l2≦1L, 2 / 3L≦l3≦1L.

[0008] Optionally, the kiss-shaped body and the winglet are connected.

[0009] Optionally, the height of the kiss-shaped body from its front end to its rear end first gradually increases and then gradually decreases.

[0010] Optionally, the kiss-shaped body is divided into a front section, a middle section and a rear section from its front end to its rear end, the height of the front section is a2, and the middle section reaches the maximum height a of the kiss-shaped body at a position where the length b2 from the front end is max , the rear section has a minimum height a of the kiss-shaped body min ; Wherein, the total length of the kiss-shaped body is B, 5≦B≦40, 1≦a2≦5, 2≦b2≦8, 1≦a min ≦4, unit: mm.

[0011] Optionally, the width of the tail-mimicking shape is C, and the depth is D, wherein 1 / 4C≦D≦1 / 2C.

[0012] Optionally, at least part of the trailing edge is tooth-shaped, and the tail-mimicking shape located at the trailing edge is tooth-shaped.

[0013] Optionally, the winglet and the kiss-shaped body are both in the form of thin sheets.

[0014] Optionally, when the blade is installed on the impeller, the blade cross-sectional parameters at the radius ∅930 with the impeller rotation axis as the center are: Cmax is 4.1mm, e is 35.5mm, b is 180.7mm, B 1A is 2 degrees, B 2A is 37 degrees, ζi is 25 degrees; the blade section parameters at radius ∅780 are: Cmax is 3mm, e is 30.9mm, b is 147.2mm, B 1A 5 degrees, B 2A is 30 degrees, ζi is 22 degrees; the blade section parameters at radius ∅630 are: Cmax is 3.3mm, e is 30.7mm, b is 137.2mm, B 1A 5 degrees, B 2A is 35 degrees, ζi is 25 degrees; the blade section parameters at radius ∅480 are: Cmax is 3.8mm, e is 39.2mm, b is 126.7mm, B 1A is 8 degrees, B 2A is 43 degrees, ζi is 33 degrees; the blade section parameters at radius ∅330 are: Cmax is 4.8mm, e is 49.3mm, b is 114.6mm, B 1A is 16 degrees, B 2A is 51 degrees, ζi is 41 degrees; Where, Cmax: C is the airfoil thickness, the distance between the normal line of the airfoil midline and the intersection of the airfoil contour line, that is, the diameter of the airfoil inscribed circle, and the maximum value of the airfoil thickness is called the maximum airfoil thickness Cmax; e: Maximum thickness position, the distance from the leading edge of the airfoil to the maximum thickness of the airfoil along the chord direction; b: chord length, the length of the chord of the wing; B 1A : The airfoil inlet geometric angle is the angle between the tangent line through the leading edge of the airfoil to the airfoil centerline and the forehead line (lower horizontal line); B 2A : The airfoil inlet geometric angle is the angle between the tangent line through the airfoil trailing edge point to the airfoil midline and the rear forehead line (upper horizontal line); ζi: airfoil installation angle, which is the angle between the chord and the frontal line of the cascade.

[0015] In the technical solution of the present invention, the design of adding a small wing to the outer edge of the blade can effectively suppress the leakage of the blade tip gap under different working conditions, maintain the efficient and stable operation of the fan, and further optimize the aerodynamic performance of the fan; the blade adopts a streamlined design of the bionic dolphin's snout at the top of the leading edge, and the snout-shaped body can greatly reduce the resistance of air flow. During the rotation of the fan blade, this design enables the blade to capture wind energy more efficiently and reduce the energy loss caused by wind resistance; the bionic whale tail structure at the trailing edge of the blade adopts a streamlined design with a horizontal fan-shaped concave, and this tail-shaped body can reduce the resistance when moving in the fluid. The combination of the above structures greatly improves the stability and overall efficiency of the fan when the blade rotates. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A front view of an embodiment of a bionic blade provided by the present invention from a first viewing angle; Figure 2 A rear view of an embodiment of a bionic blade provided by the present invention from a first viewing angle; Figure 3 A front view of an embodiment of a bionic blade provided by the present invention from another perspective; Figure 4 A top view of an embodiment of a bionic blade provided by the present invention from another perspective; Figure 5 for Figure 1 A partial enlarged view of the middle A; Figure 6 for Figure 1 Schematic diagram of the segmentation of each radius; Figure 7It is the front view of a conventional blade; Figure 8 A bionic schematic diagram of a bionic blade provided by the present invention; Fig. 9 It is the name diagram of the intersection line of the blade surface; Fig.10 A curve intersection line diagram of a bionic blade in accordance with the present invention at a cross section of ∅930; Fig.11 A curve intersection line diagram of a bionic blade in accordance with the present invention at a cross section of ∅780; Fig.12 A curve intersection line diagram of a bionic blade provided by the present invention at a section ∅630; Fig.13 A curve intersection line diagram of a bionic blade provided by the present invention at a cross section of ∅480; Fig.14 A curve intersection line diagram of a bionic blade provided by the present invention at a section ∅330; Fig.15 A comparison table of wind volume test data of an embodiment of a bionic blade provided by the present invention and a conventional blade; Fig.16 A comparison chart of wind volume test data of an embodiment of a bionic blade provided by the present invention and a conventional blade; Fig.17 A conventional blade noise test spectrum diagram provided by the present invention; Fig.18 A noise test spectrum diagram of an embodiment of a bionic blade provided by the present invention; Fig.19 A spectrum value table of conventional blades provided by the present invention; Fig. 20 This is a spectrum value table of an embodiment of the bionic blade provided by the present invention.

[0018] In the figure: blade-100, outer edge-1, winglet-11, lower part of winglet-112, upper part of winglet-113, bionic snout-shaped body-12, front section-121, middle section-122, rear section-123, rear edge-2, bionic tail-shaped body-21, petiole-3, leading edge-4, leaf surface-5, bionic dorsal fin-51.

[0019] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] In order to better describe and illustrate the embodiments of the present application, reference may be made to one or more drawings, but the additional details or examples used to describe the drawings should not be considered as limiting the scope of the invention of the present application, any of the currently described embodiments or preferred methods.

[0022] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" are based on the positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention. They do not indicate that the device referred to must have a specific direction or operate in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0024] Due to design and material limitations, traditional fan blades may have problems such as poor aerodynamic performance, heavy weight, and low efficiency. These problems will affect the overall performance and application range of the fan, increase operating costs, and not meet the requirements of energy conservation and emission reduction.

[0025] In view of this, the present invention proposes a bionic blade. Figure 1-6 For a structural diagram of an embodiment of a bionic blade provided by the present invention, please refer to Figure 1-6 The blade 100 has an inner side near the petiole 3 and an outer side away from the petiole 3. The outer side of the blade 100 is provided with a winglet 11 extending along its outer edge 1 and extending relative to the front and back sides of the blade 100. The winglet 11 is in a sheet shape and connected to the outer edge 1 of the blade 100. The outer side of the blade 100 is provided with a kiss-shaped body 12 connected to its outer edge 1; see Figure 8The snout-shaped body 12 is a streamlined sheet-like structure, and its shape is similar to the snout of a dolphin. The snout-shaped body 12 protrudes forward from the front end of the outer edge 1 (i.e., the top of the leading edge 4, which is the wind-cutting part) to form a flange. The trailing edge 2 of the outer side of the blade 100 is at least partially concave compared to the ordinary blade 100, and the concave direction is concave toward the leading edge. The missing concave part is approximately horizontally fan-shaped, and a tail-shaped body 21 with an arc-shaped edge is formed at the rear end of the blade 100; please refer to Figure 8 The tail-like body 21 is similar to the horizontal tail of a whale. It should be noted that, in order to reduce the weight of the blade 100, the blade 100 and its winglet 11, the snout-like body 12, and the tail-like body 21 are integrally injection molded.

[0026] In the technical solution of the present invention, the design of adding a winglet 11 to the outer edge 1 of the blade 100 can effectively suppress the leakage of the blade tip gap under different working conditions, maintain the efficient and stable operation of the fan, and further optimize the aerodynamic performance of the fan; the blade 100 adopts a streamlined design of a bionic dolphin's snout at the top of the leading edge 4 (i.e., the front end of the outer edge 1), and the snout-shaped body 12 can greatly reduce the resistance of air flow. During the rotation of the fan blade 100, this design enables the blade 100 to capture wind energy more efficiently and reduce the energy loss caused by wind resistance; the bionic whale tail structure of the trailing edge 2 of the blade 100 adopts a streamlined design with a horizontal fan-shaped concave, and this tail-shaped body 21 can reduce the resistance when moving in the fluid. The combination of the above structures greatly improves the stability and overall efficiency of the fan when the blade 100 rotates.

[0027] To effectively suppress the leakage of the blade tip clearance of blade 100, please refer to Figure 1 , 2 and 4. In one embodiment of the present invention, the winglet 11 is embodied as a blade-shaped heightened structure in appearance, with a sharp front, a wide middle section 122, and a convergent rearward position at the rear end. Specifically, the winglet 11 is divided into a winglet lower portion 112 and a winglet upper portion 113 relative to the outer edge 1 of the blade 100. The height of the winglet lower portion 112 gradually increases and then gradually decreases from the front end to the rear end, and the height of the winglet upper portion 113 gradually increases and then gradually decreases from the front end to the rear end. Such a design can effectively suppress the leakage of the tip gap of the blade 100 and has many advantages for the operation of the fan. Among them, the height here refers to the distance it extends relative to the front and back sides of the blade 100.

[0028] For further information, see Figure 4 In some embodiments of the present invention, the lower portion 112 of the winglet reaches its highest point h at the position of its length l1. 1max The upper part 113 of the winglet reaches its highest point h at the position of its length l2 2max The winglet 11 reaches its highest H at the position of its length l3max ; Among them, the total length of the winglet 11 is L, 1 / 3L≦l1≦2 / 3L, 2 / 3L≦l2≦1L, 2 / 3L≦l3≦1L.

[0029] It should be noted that the design of the winglet 11 on the outer edge 1 of the blade 100 has the following advantages.

[0030] Improve fan efficiency: Suppressing tip gap leakage is one of the important means to improve fan efficiency. Tip gap leakage will cause part of the airflow to pass through the gap directly without passing through the blade 100 to do work, thereby reducing the aerodynamic efficiency of the fan. The winglet 11 on the outer edge 1 can effectively prevent such leakage, allowing more airflow to pass through the blade 100 to do work, thereby improving the overall efficiency of the fan.

[0031] Reduce energy loss: Leakage in the tip clearance will not only reduce the aerodynamic efficiency of the fan, but also cause energy waste. By adding the winglets 11 on the outer edge 1, the amount of leaked air can be reduced, thereby reducing energy loss, so that the fan can output more air volume under the same conditions.

[0032] Reduce noise: Blade tip gap leakage is often accompanied by strong eddy currents and turbulence, which are one of the main sources of fan noise. By suppressing blade tip gap leakage, the formation of eddy currents and turbulence can be reduced, thereby reducing the operating noise of the fan and improving the noise environment around the fan.

[0033] Improve the durability of the blade 100: The vortex and turbulence generated by the tip clearance leakage will cause scouring and wear on the outer edge 1 surface of the blade 100, which will reduce the service life of the blade 100 in the long run. By adding the winglet 11 on the outer edge 1 to suppress leakage, the impact and wear of the vortex and turbulence on the blade 100 can be reduced, thereby improving the durability and reliability of the blade 100.

[0034] Adapt to different working conditions: During the operation of the fan, various complex working conditions may be encountered, such as changes in wind speed and wind direction. The design of the winglets 11 on the outer edge 1 can effectively suppress the leakage of the blade tip gap under different working conditions and maintain the efficient and stable operation of the fan. This design helps to improve the adaptability and reliability of the fan.

[0035] Optimizing aerodynamic performance: The shape of the winglet 11 on the outer edge 1 can further optimize the aerodynamic performance of the fan. In one embodiment of the present invention, the kiss-shaped body 12 is connected to the winglet 11, and the connection between the two is a smooth transition. The kiss-shaped body 12 is a dolphin-like snout structure at the top of the leading edge 4 on the outside of the blade 100 (that is, the front end of the trailing edge 2). Since the dolphin's snout presents a streamlined structure, it has obvious advantages in terms of fluid. The front end of the kiss-shaped body 12 is round and smooth, the middle section 122 is relatively thick, and the cross-section of the transition section with the sheet-like winglet 11 at the outer edge 1 gradually decreases.

[0036] To better imitate the dolphin's snout, see Figure 1 and 5 The height of the kiss-shaped body 12 from the front end to the rear end first gradually increases and then gradually decreases. The height here refers to the distance extended relative to the front and back sides of the blade 100.

[0037] For further information, see Figure 5 In one embodiment of the present invention, the kiss-shaped body 12 is divided into a front section 121, a middle section 122 and a rear section 123 from its front end to its rear end. The height of the front section 121 is a2, and the middle section 122 reaches the maximum height a of the kiss-shaped body 12 at a position where the length b2 from the front end is max The rear section 123 has a minimum height a of the kiss-shaped body 12. min ; Wherein, the total length of the kiss-shaped body 12 is B, 5≦B≦40, 1≦a2≦5, 2≦b2≦8, 1≦a min ≦4, unit: mm.

[0038] It should be noted that the kiss-shaped body 12 imitates the dolphin's kiss and has the following advantages.

[0039] Streamlined design: The dolphin's snout has a streamlined feature, and this shape can minimize the resistance of water flow. When swimming quickly, the streamlined snout allows the dolphin to pass through the water more efficiently and reduce energy loss. The fan adopts a streamlined design that imitates the dolphin's snout to significantly reduce the resistance of air flow. During the rotation of the fan blade 100, this design allows the blade 100 to capture wind energy more efficiently, reduce energy loss caused by wind resistance, and thus improve the overall efficiency of the fan.

[0040] Smooth surface: The dolphin's skin is smooth, which further reduces the friction resistance of the water flow. Combined with the snout, this smooth surface design allows the dolphin to swim more smoothly in the water. The streamlined features of the dolphin's snout allow the air to transition smoothly when flowing through the leading edge 4 of the blade 100, reducing turbulence and eddies caused by air flow separation. This not only helps to reduce the noise level when the fan is running, but also reduces the mechanical stress caused by vibration and prolongs the service life of the blade 100.

[0041] Adapt to different speeds: Whether swimming at a low speed or sprinting at a high speed, the dolphin's snout can adapt well to the changes in water flow and maintain the stability and efficiency of swimming. The bionic design of the dolphin's snout enables the fan blade 100 to adapt well to different wind speed conditions. Whether it is low-speed wind or high-speed wind, the blade 100 can maintain a stable operating state, ensuring that the fan can operate efficiently at different wind speeds. This adaptability is of great significance to improving the reliability and stability of the fan.

[0042] Protection mechanism: The dolphin's snout plays a buffering role to a certain extent, protecting the dolphin from damage during swimming or hunting. Although the dolphin's snout itself does not directly have the function of enhancing mechanical strength, the bionic design can inspire us to use a similar buffering structure on the leading edge 4 of the blade 100 to reduce the impact on the blade 100 under extreme environmental conditions (such as strong winds, hail, firefighting, rain and snow, etc.). This can protect the blade 100 from damage to a certain extent and improve its durability.

[0043] Unique appearance: The snout, as one of the prominent features of a dolphin's face, adds a unique charm to them, which makes it easier for people to identify and distinguish them. The design of the bionic dolphin's snout gives the fan blade 100 a unique appearance and increases its aesthetics. At the same time, this design also makes the blade 100 more visually eye-catching, which helps to improve the recognition and identification of the fan.

[0044] In summary, the leading edge 4 of the blade 100 adopts a bionic dolphin snout design, which can bring many benefits, including reducing wind resistance, reducing noise and vibration, adapting to different wind speed conditions, enhancing the structural strength and durability of the blade 100, and improving aesthetics and recognition, etc. These advantages will help improve the overall performance and operating efficiency of the wind turbine.

[0045] See also Figure 1 and 5 It should be noted that, in one embodiment of the present invention, the winglet 11 and the kiss-shaped body 12 are both in the form of thin sheets, both are connected to the outer edge 1 of the blade 100, and the connection between the two is a smooth transition. The winglet 11 and the kiss-shaped body 12 are both integrally injection molded with the blade 100. Of course, the thickness of the winglet 11 and the kiss-shaped body 12 can be adaptively adjusted according to their application in the fan, which will not be described in detail here.

[0046] To better mimic the horizontal tail structure of a whale, please refer to Figure 3 and Figure 7 In one embodiment of the present invention, compared with conventional blades, the width (i.e., the concave width) of the tail-like body 21 at the trailing edge 2 of the outer side of the blade 100 of this embodiment is C, and the depth (i.e., the concave depth) is D, wherein 1 / 4C≦D≦1 / 2C. These structural designs make the tail-like body 21 closer to the horizontal tail structure of a whale.

[0047] It should be noted that the design of the tail-like shape 21 at the trailing edge 2 of the blade 100 has the following advantages.

[0048] Streamlined design of the bionic tail: The bionic whale tail structure adopts a streamlined design in a horizontal fan shape to reduce the resistance when moving in the fluid. The whale's tail is a horizontal fan-shaped structure, which is significantly different from the vertical tail of fish. This shape allows the whale to use the water flow more effectively when swimming, improving the swimming efficiency. The bionic whale tail structure adopts a streamlined design to reduce the resistance when moving in the fluid. This design is beautiful, conforms to the principles of aerodynamics or fluid mechanics, and helps to improve the overall performance of the mechanical structure.

[0049] The thickness of the blade 100 in the part imitating the whale's tail (i.e., the tail-shaped body 21) shows an overall trend of decreasing thickness from front to back, aiming to reduce the separation vortex of the trailing edge 2 and thus reduce noise. This design is aesthetically pleasing and conforms to the principles of aerodynamics or fluid mechanics, which helps to improve the overall performance of the mechanical structure. In the impeller structure, it is reflected in improving efficiency and reducing ineffective work.

[0050] To better reduce the noise generated by the blade 100 when it rotates, please refer to Figure 1 and 2 In one embodiment of the present invention, at least a portion of the trailing edge 2 is tooth-shaped, and the tail-mimicking body 21 located at the trailing edge 2 is tooth-shaped.

[0051] Nodular edge of bionic tail: Imitating the nodular characteristics of whale flippers, the outer side of the trailing edge 2 of the blade 100 is designed with a series of trailing edge noise reduction teeth to imitate the nodular edge of a whale. These nodular / serrated structures can generate vortex effects in the fluid, thereby increasing lift and reducing drag.

[0052] The bionic part shows bifurcation and thickness changes. The whale's tail starts from a solid and round tail root, gradually bifurcates and finally splits into two pieces. The two pieces of the tail are separated from each other and are far apart in the middle. The tail is relatively thin at the end, but the whole is wide, hard and flat. In the impeller design, this structure is imitated, and a large groove is used to imitate the bifurcation of the tail without generating obvious stress concentration, preventing the sharp corner in the middle of the large groove from tearing and breaking.

[0053] In order to improve the curved surface of the blade 5 of the blade 100 so that it can work efficiently, in one embodiment of the present invention, when the blade 100 is installed on the impeller, the impeller rotation axis is taken as the center of the circle, and the unit is mm, see Figure 10-14 , the blade section parameters at radius ∅930 are: Cmax is 4.1mm, e is 35.5mm, b is 180.7mm, B 1A is 2 degrees, B 2A is 37 degrees, ζi is 25 degrees; the blade section parameters at radius ∅780 are: Cmax is 3mm, e is 30.9mm, b is 147.2mm, B 1A 5 degrees, B2A is 30 degrees, ζi is 22 degrees; the blade section parameters at radius ∅630 are: Cmax is 3.3mm, e is 30.7mm, b is 137.2mm, B 1A 5 degrees, B 2A is 35 degrees, ζi is 25 degrees; the blade section parameters at radius ∅480 are: Cmax is 3.8mm, e is 39.2mm, b is 126.7mm, B 1A is 8 degrees, B 2A is 43 degrees, ζi is 33 degrees; the blade section parameters at radius ∅330 are: Cmax is 4.8mm, e is 49.3mm, b is 114.6mm, B 1A is 16 degrees, B 2A is 51 degrees, ζi is 41 degrees; Among them, see Fig. 9 , Cmax: C is the airfoil thickness, the distance between the normal line of the airfoil midline and the intersection of the airfoil contour line, that is, the diameter of the airfoil inscribed circle. The maximum value of the airfoil thickness is called the maximum airfoil thickness Cmax; e: Maximum thickness position, the distance from the leading edge of the airfoil to the maximum thickness of the airfoil along the chord direction; b: chord length, the length of the chord of the wing; B 1A : The airfoil inlet geometric angle is the angle between the tangent line through the leading edge of the airfoil to the airfoil centerline and the forehead line (lower horizontal line); B 2A : The airfoil inlet geometric angle is the angle between the tangent line through the airfoil trailing edge point to the airfoil midline and the rear forehead line (upper horizontal line); ζi: airfoil installation angle, which is the angle between the chord and the frontal line of the cascade.

[0054] As a preferred embodiment, please refer to Figure 1 The blade 100 has a plurality of bionic dorsal fins 51 on its curved surface 5. The bionic dorsal fins 51 are convex ribs on the blade 5, extending from the front side to the rear side of the blade 100, and the height increases continuously. The bionic dorsal fins 51 are equally spaced on the blade 5, and the length of each bionic dorsal fin 51 increases continuously from the inner side to the outer side of the blade 100.

[0055] It should be noted that the purpose of the bionic curved surface design is to imitate the biological structure design of the polypterus in nature, with multiple bionic dorsal fins 51 attached to the back. The curved surface combined with the bionic dorsal fin 51 on the back can achieve the following effects.

[0056] Improve aerodynamic performance: Bionic surface design imitates the curved shapes of organisms in nature (such as bird wings, fish fins, etc.). These shapes have excellent fluid dynamic performance after a long period of natural selection and evolution. Applying these curved shapes to axial flow impellers can optimize the fluid dynamic characteristics of the blades, reduce the resistance and energy consumption during fluid flow, and thus improve the aerodynamic efficiency and output power of the impeller.

[0057] Reduce noise: The bionic surface design can more effectively control the flow state of the fluid on the blade surface and reduce the generation of unstable flow phenomena such as eddy currents and turbulence. These unstable flow phenomena are one of the main causes of fluid mechanical noise, so the bionic surface design helps to reduce the noise level of the axial flow impeller, making it more in line with environmental protection and energy saving requirements.

[0058] Enhanced structural stability: Bionic surface design often has a more reasonable stress distribution and strength distribution, which helps to enhance the structural stability and durability of the axial flow impeller. Under high load or harsh working conditions, the bionic surface design can better withstand the impact and vibration of the fluid, thereby extending the service life of the impeller.

[0059] Optimize flow and pressure distribution: The bionic curved surface design can finely adjust the curved surface shape of the blade according to the actual working conditions to achieve a more uniform flow and pressure distribution. This helps to reduce the turbulence and backflow of the fluid inside the impeller and improve the flow efficiency and stability of the fluid.

[0060] Broaden the scope of application: Due to the advantages of bionic surface design in aerodynamic performance, noise control, structural stability, etc., axial flow impellers can be more widely used in various fields. For example, in the fields of ventilation, air conditioning and refrigeration, axial flow impellers with bionic surface design can provide more efficient, energy-saving and environmentally friendly solutions.

[0061] In this embodiment, the noise and efficiency of the bionic blade 100 with the above structure and the conventional blade without the above structure are actually compared. In the specific implementation, 5 samples of each are made using 3D printing technology, and the same parts and components from the same batch (hub, sleeve, buckle cover, fairing) are used to assemble the impeller, and then the same panel, air guide ring, mesh cover and motor (860RPM) are matched. Please refer to Figure 15-20 , Figure 15-20 The data are the static pressure test data of 100,000 wind chamber air volume and the spectrum comparison data of one-third frequency test in semi-anechoic laboratory.

[0062] See also Fig.16 The results show that the overall air volume of the bionic blade 100 is basically the same as that of the conventional blade that does not adopt the above structure, the efficiency is increased by about 4%, and the noise is reduced by 2.3dB.

[0063] See also Figure 17-20 By comparing the numerical tables of the one-third octave frequency spectrum of the two, it is found that the bionic blade 100 using the above structure and the conventional blade without the above structure have a decrease of 4 [Pa] (A) in the 80Hz frequency band. This frequency band generally belongs to the aerodynamic noise formed by the vortex generated by the airflow shedding at the trailing edge of the blade. In addition, the 80Hz frequency band is a noise peak in the range of 20~125Hz. The peak reduction can effectively reduce the overall noise. And all frequency bands in the range of 400~20000Hz have shown a significant reduction. The overall noise found that under the same working conditions, the average noise of the bionic blade with the addition of the tail-shaped body 20 was reduced by 2.3dB.

[0064] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A bionic leaf having an inner side close to its petiole and an outer side away from the petiole, characterized in that: The outer side of the blade is provided with a winglet (11) extending along the outer edge (1) of the blade; The outer side of the blade is provided with a kiss-shaped body (12) connected to the outer edge (1) thereof, the kiss-shaped body (12) being of a streamlined structure and protruding forward from the front end of the outer edge; The outer rear edge (2) of the blade is at least partially concave, forming a tail-like shape (21).

2. The bionic blade according to claim 1, characterized in that: The winglet (11) is divided into a winglet lower portion (112) and a winglet upper portion (113) relative to the outer edge (1) of the blade, wherein the height of the winglet lower portion (112) gradually increases and then gradually decreases from the front end to the rear end, and the height of the winglet upper portion (113) gradually increases and then gradually decreases from the front end to the rear end.

3. The bionic blade according to claim 2, characterized in that: The lower part (113) of the winglet reaches its maximum h at the position of its length l1 1max The upper part of the winglet (113) reaches the highest h at the position of its length l2. 2max , the winglet (11) reaches its highest H at the position of its length l3 max ; The total length of the winglet (11) is L, 1 / 3L≦l1≦2 / 3L, 2 / 3L≦l2≦1L, 2 / 3L≦l3≦1L.

4. The bionic blade according to claim 1, characterized in that: The kiss-shaped body (12) is connected to the winglet (11).

5. The bionic blade according to claim 1, characterized in that: The height of the kiss-shaped body (12) gradually increases and then gradually decreases from the front end to the rear end.

6. The bionic blade according to claim 1, characterized in that: The kiss-shaped body (12) is divided into a front section (121), a middle section (122) and a rear section (123) from its front end to its rear end. The height of the front section (121) is a2, and the middle section (122) reaches the maximum height a of the kiss-shaped body (12) at a position where the length b2 from the front end is max The rear section (123) has a minimum height a of the kiss-shaped body. min ; The total length of the kiss-shaped body (12) is B, 5≦B≦40, 1≦a2≦5, 2≦b2≦8, 1≦a min ≦4, unit: mm.

7. The bionic blade according to claim 1, characterized in that: The tail-mimicking shape (21) has a width of C and a depth of D, wherein 1 / 4C≦D≦1 / 2C.

8. The bionic blade according to claim 1, characterized in that: The trailing edge (2) is at least partially tooth-shaped, and the tail-mimicking body (21) located at the trailing edge (2) is tooth-shaped.

9. The bionic blade according to claim 1, characterized in that: The winglet (11) and the kiss-shaped body (12) are both in the form of thin sheets.

10. The bionic blade according to claim 1, characterized in that: When the blade is installed on the impeller, the blade cross-sectional parameters at the radius ∅930 with the impeller rotation axis as the center are: Cmax is 4.1mm, e is 35.5mm, b is 180.7mm, B 1A is 2 degrees, B 2A is 37 degrees, ζi is 25 degrees; the blade section parameters at radius ∅780 are: Cmax is 3mm, e is 30.9mm, b is 147.2mm, B 1A 5 degrees, B 2A is 30 degrees, ζi is 22 degrees; the blade section parameters at radius ∅630 are: Cmax is 3.3mm, e is 30.7mm, b is 137.2mm, B 1A 5 degrees, B 2A is 35 degrees, ζi is 25 degrees; the blade section parameters at radius ∅480 are: Cmax is 3.8mm, e is 39.2mm, b is 126.7mm, B 1A is 8 degrees, B 2A is 43 degrees, ζi is 33 degrees; the blade section parameters at radius ∅330 are: Cmax is 4.8mm, e is 49.3mm, b is 114.6mm, B 1A is 16 degrees, B 2A is 51 degrees, ζi is 41 degrees; Where, Cmax: C is the airfoil thickness, the distance between the normal line of the airfoil midline and the intersection of the airfoil contour line, that is, the diameter of the airfoil inscribed circle, and the maximum value of the airfoil thickness is called the maximum airfoil thickness Cmax; e: Maximum thickness position, the distance from the leading edge of the airfoil to the maximum thickness of the airfoil along the chord direction; b: chord length, the length of the chord of the wing; B 1A : The airfoil inlet geometric angle is the angle between the tangent line through the leading edge of the airfoil to the airfoil midline and the forehead line; B 2A : The airfoil inlet geometric angle is the angle between the tangent line through the airfoil trailing edge point to the airfoil midline and the rear forehead line; ζi: airfoil installation angle, which is the angle between the chord and the frontal line of the cascade.

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