Design method of bionic ocean current generator blade based on characteristics of owl wing

Abstract

The application provides a design method of a biomimetic ocean current generator blade based on the characteristics of an owl wing, comprising the following steps: obtaining a prototype blade design parameter; calculating and selecting at least one sweepback length; selecting a plurality of sweepback angles; establishing a prototype blade model and a plurality of biomimetic ocean current generator blade models; calculating the torque of the impeller of the prototype blade and each biomimetic ocean current generator blade by a numerical simulation method; calculating and comparing the power coefficient of the prototype blade and the power coefficient of each biomimetic ocean current generator blade; and selecting a biomimetic ocean current generator blade with a power coefficient greater than that of the prototype blade. The purpose of the application is to provide a design method of a biomimetic ocean current generator blade based on the characteristics of an owl wing, to design an ocean current generator blade with a sweepback part by imitating the structure of an owl wing, and to obtain a sweepback length and a sweepback angle range of the biomimetic ocean current generator blade with a power coefficient greater than that of the prototype blade.

Description

Technical Field

[0001] This invention belongs to the field of ocean current power generation technology, specifically a design method for biomimetic ocean current generator blades based on the characteristics of owl wings. Background Technology

[0002] The finite nature of fossil fuels and the pollution caused by their use are global concerns, making the development of new energy sources imperative. my country possesses abundant marine energy resources, and its geographical conditions are highly favorable for utilizing ocean currents for industrial-scale power generation. The blades are the most critical core component of ocean current generators. Exposed to corrosive seawater, they bear the complex coupled loads of ocean waves and currents; their reliability and efficiency are crucial to the effective development and utilization of ocean current energy.

[0003] Most existing ocean current generator blades are designed based on the experience gained from wind turbine blade design, resulting in very similar external shapes. However, ocean current generator blades operate in seawater, while wind turbine blades operate in air. The different viscosities of seawater and air lead to different operating efficiencies for the same blade in seawater and air. When existing prototype blades used in wind power generation are used as ocean current generator blades, significant cavitation occurs at the blade tips, leading to reduced impeller efficiency.

[0004] In addition, ocean current generators operate underwater, close to the water surface. During their operation, the pressure on the blade surface will experience periodic pressure pulsations due to the rotation of the blades and the disturbance of the sea waves, which will cause cavitation on the blade tip surface and lead to cavitation damage to the blade structure. Summary of the Invention

[0005] To address the aforementioned problems in existing technologies, the purpose of this invention is to provide a design method for biomimetic ocean current generator blades based on the characteristics of owl wings. The invention designs ocean current generator blades with swept-back sections, mimicking the structure of owl wings. The design method is implemented through calculation and simulation software, which can obtain the sweep length and sweep angle range of the biomimetic ocean current generator blades with a power coefficient greater than that of the prototype blades.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A design method for biomimetic ocean current generator blades based on owl wing features, including

[0008] Step S1: Obtain the prototype blade design parameters;

[0009] Step S2: Calculate and select at least one sweep length;

[0010] Step S3: Select multiple sweep angles within the range of 0 to 90°;

[0011] Step S4: Establish a prototype blade model, using a sweep length and a sweep angle as a set of sweep structure parameters to obtain multiple sets of sweep structure parameters, and establish multiple biomimetic ocean current generator blade models based on the prototype blade and each set of sweep structure parameters.

[0012] Step S5: Calculate the impeller torque of the prototype blade and each biomimetic ocean current generator blade using numerical simulation methods;

[0013] Step S6: Calculate and compare the power coefficient of the prototype blade with the power coefficient of each of the biomimetic ocean current generator blades;

[0014] Step S7: When the power coefficient of the biomimetic ocean current generator blade is greater than that of the prototype blade, the biomimetic ocean current generator blade can be selected as the final biomimetic ocean current generator blade.

[0015] As a further improvement to the above technical solution:

[0016] In step S3, multiple sweep angles are selected by searching using the binary search method.

[0017] The distance between the root end face and the tip end face of the prototype blade is equal to the distance between the root end face and the tip end face of the biomimetic ocean current generator blade.

[0018] The biomimetic ocean current generator blade includes a main body and a swept portion, which are integrally connected. The interface between the main body and the swept portion is a second cross section. The portion between the second cross section and the tip end face of the biomimetic ocean current generator blade is the swept portion. The distance between the second cross section and the tip end face of the biomimetic ocean current generator blade is the swept length.

[0019] Assume that the prototype blade has a third cross section, and the third cross section and the tip end face of the prototype blade are arranged parallel to each other at intervals. The distance between the third cross section and the tip end face of the prototype blade is the sweep length. The structure of the main body is the same as the structure between the tip end face of the prototype blade and the third cross section.

[0020] In step S2, the formula for calculating and selecting the sweep length L is L = L4n1 / n2, where n1 and n2 are natural numbers, 1 ≤ n1 ≤ n2, n2 = 5 to 20, and L4 is the distance between the end face of the tip of the prototype blade and the cross section where the most concave part of the trailing edge is located.

[0021] In step S6,

[0022]

[0023] A = πR 2

[0024]

[0025] The multiple blades are connected to the hub to form an impeller.

[0026] Where ω represents the angular velocity of the impeller; ρ represents the density of the fluid; A represents the swept area of ​​the rotor; R represents the distance between the center point of the hub and the intersection of the sweep curve and the end face of the blade tip; U ∞ The inlet current velocity is represented by the sweep curve, which is the line connecting the aerodynamic centers of the airfoils at each cross-section of the swept section. L1 is the distance between the hub center point of the impeller and the end face of the blade root. L2 is the distance between the end face of the blade root and the cross-section where the trailing edge is most concave. For the prototype blade, L3 is the distance between the cross-section where the trailing edge is most concave and the third cross-section. For the biomimetic ocean current generator blade, L3 is the distance between the cross-section where the trailing edge is most concave and the second cross-section.

[0027] The distance between the root end face and the tip end face of the biomimetic ocean current generator blade is 2.86m.

[0028] When the sweep length L = 0.272m, the sweep angle β = 0–47.8°; when the sweep length L = 0.544m, the sweep angle β = 0–45.31°; when the sweep length L = 1.088m, the sweep angle β = 0–45.31°; when the sweep length L = 1.36m, the sweep angle β = 0–42.59°.

[0029] The sweep length L = 0.544 m, β = 28.88°.

[0030] The beneficial effects of this invention are as follows: A biomimetic ocean current generator blade with a swept-back section is designed, mimicking the structure of an owl's wing. This design method is implemented using calculation and simulation software, requiring no raw materials and thus having a low cost. It can obtain a range of swept-back lengths and angles for the biomimetic ocean current generator blade with a power coefficient greater than that of the prototype blade, and find the larger power coefficient within this range. The biomimetic ocean current generator blade is based on an improved standard blade. Compared to the prototype blade, the biomimetic ocean current generator blade maintains a higher power coefficient than the standard blade even after cavitation, without significantly altering the swept area. This improves the working efficiency of the ocean current generator rotor and increases the power coefficient of the ocean current generator. Furthermore, the ocean current generator blade is simple to manufacture and does not significantly increase costs compared to the standard blade. Attached Figure Description

[0031] Figure 1 This is an illustration of an owl.

[0032] Figure 2 yes Figure 1 A schematic diagram after image processing.

[0033] Figure 3 yes Figure 1 The diagram shows the outline of an owl.

[0034] Figure 4 This is a flowchart of the design method of the present invention.

[0035] Figure 5 This is a schematic diagram of the prototype blade structure of one embodiment of the present invention.

[0036] Figure 6 This is a schematic diagram of an impeller structure based on a prototype blade according to an embodiment of the present invention.

[0037] Figure 7 This is a schematic diagram of the biomimetic ocean current generator blade structure according to an embodiment of the present invention.

[0038] Figure 8 This is a schematic diagram of the impeller structure based on the biomimetic ocean current generator blades of one embodiment of the present invention.

[0039] Figure 9 This is a comparison diagram of the power coefficients of a prototype blade and a biomimetic ocean current generator blade under different tip speed ratios, according to an embodiment of the present invention.

[0040] Figure 10 This is a schematic diagram of the velocity decomposition of the swept-back portion of a biomimetic ocean current generator blade according to an embodiment of the present invention. Detailed Implementation

[0041] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0042] 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.

[0043] A design method for biomimetic ocean current generator blades based on the characteristics of owl wings, where the owl wing shape is like... Figures 1-3 The study found that owls possess characteristics such as high flight speed (up to 45 km / h), stable flight, and silent flight, indicating that their wings can overcome air interference to a certain extent, or capture air energy, exhibiting superior stability. Owl wings are long and narrow, with a swept-back structure located at the wingtip. Similarly, the performance of the blade tip directly affects the efficiency of an ocean current generator. Based on this, inspired by the characteristics of owl wings, ocean current generator blades with a swept-back structure are designed to improve the blade's energy capture efficiency, thereby increasing the power output of the ocean current generator.

[0044] The design method is as follows Figure 4 As shown, it includes the following steps:

[0045] Step S1: Obtain the prototype blade design parameters.

[0046] The prototype blades can be made using existing ocean current generator blades.

[0047] In this embodiment, the prototype blade structure used is as follows: Figure 5 As shown, the impeller formed by connecting the blade roots of multiple prototype blades to the hub g is as follows: Figure 6 As shown in Table 1, the design parameters of the prototype blade can be designed and manufactured according to the parameters in Table 1.

[0048] Table 1: Prototype Blade Shape Design Parameters

[0049]

[0050]

[0051] It should be noted that the design parameter in Table 1, where the length is 0m, is the center point O1 of the hub g.

[0052] The prototype blade has no swept-back structure. Based on the fluid flow direction, the fluid flows into the blade channel from the leading edge q and out from the trailing edge w. The leading edge q of the prototype blade is relatively gentle, while the trailing edge w is steeper than the leading edge q. Specifically, along the spanwise direction, the trailing edge w first descends and then rises, meaning its trajectory resembles a parabola with a concave point.

[0053] Let the root end of the prototype blade be A' and the tip end be B'. The end faces of A' and B' are arranged parallel and spaced apart. The shape of the end face of A' is circular; the end face of B' is airfoil-shaped. Let the cross section where the most concave part of the trailing edge w is located be the first cross section y, which is parallel to the end face of A'. Let the prototype blade have a third cross section s, which is arranged parallel and spaced apart from the end face of A', and is located between the first cross section y and the end face of B'.

[0054] For the prototype blade, let L1 be the distance between the center point O1 of the hub g and one end face of the blade root, L2 be the distance between the end face of A' and the first cross-section y, L3 be the distance between the first cross-section y and the third cross-section s, and L be the distance between the third cross-section s and the end face of B'. From Table 1, the span at the end face of B' is r = L1 + L2 + L3 + L = 3.2 m. In this embodiment, the span at the first cross-section y of the prototype blade is r = L1 + L2 = 0.752 m.

[0055] Step S2: Calculate and select at least one sweep length L.

[0056] The formula for calculating and selecting the sweep length L is as follows:

[0057] L=L4n1 / n2

[0058] L4 = L3 + L

[0059] Where n1 and n2 are natural numbers, 1≤n1≤n2, and n2=5~20.

[0060] L4 is the distance between the first cross section y and the end face of B', or the span of the end face of B' minus the span of the first cross section y.

[0061] The above formula can be understood as follows: the portion between the first cross section y of the prototype blade and the end face of B' is divided into n2 equal parts. If the length of each part is a unit length, then the sweep length L is equal to the unit length, or an integer multiple of the unit length.

[0062] As shown in Table 1, in this embodiment, the first cross section y passes through a twist angle of 19°, corresponding to a span of r = 0.752m, so L4 = 3.2 - r = 2.448m.

[0063] In this embodiment, n2 = 9 and n1 takes four values: 1, 2, 4, and 5, to obtain four values ​​of sweep length L, as shown in Table 2.

[0064] Table 2 Calculation Table for Swept Length L

[0065] <![CDATA[n2]]> 9 9 9 9 <![CDATA[n1]]> 1 2 4 5 Sweep length L (m) 0.272 0.544 1.088 1.36

[0066] The sweep length L is obviously less than L4. The above n2 is a natural number between 5 and 20, which is based on practical experience. Dividing L4 into equal parts of 5 to 20, and then combining it with the supplement of n1, can further refine the verification and calculation range of the sweep length L.

[0067] Step S3: Select multiple sweep angles β by using the binary search method.

[0068] In this step, 0° < β < 90°.

[0069] Step S4: Establish a prototype blade model. Using a sweep length L and a sweep angle β as a set of sweep structural parameters, obtain multiple sets of sweep structural parameters. Based on the prototype blade and each set of sweep structural parameters, establish multiple biomimetic ocean current generator blade models.

[0070] like Figure 7 and Figure 8 As shown, the biomimetic ocean current generator blade includes a main body 1 and a swept-back portion 2, which are integrally connected. The blade root end is designated as end A, and the blade tip end is designated as end B. The interface between the main body 1 and the swept-back portion 2 is a second cross-section e. The structure between the end face at end A and the second cross-section e constitutes the main body 1, and the structure between the second cross-section e and the end face at end B constitutes the swept-back portion 2. The end face at end A, the end face at end B, and the second cross-section e are parallel. The end face at end A is circular; the end face at end B is airfoil-shaped.

[0071] The structure of the main body 1 is the same as the corresponding part of the prototype blade. In other words, the structure of the main body 1 is the same as the structure from the A' end face to the third section s of the prototype blade. The distance between the A' end face and the third section s is equal to the distance between the A end face and the second section e of the biomimetic ocean current generator blade. That is, from the A end face to the second section e, the chord length C and twist angle θ of each blade element of the main body 1 are consistent with those of the prototype blade. That is, the main body 1 has a first section y.

[0072] From the dimensions of the prototype blade, it can be seen that for the impeller formed by the biomimetic ocean current generator blade connected to the hub g, the distance from the center point O1 of the hub g to the blade root is obviously L1, the distance between the A-end face and the first cross-section y is L2, the distance between the first cross-section y and the second cross-section e is L3, and the distance between the second cross-section e and the B-end face is L. That is, the distance from the A' end face to the B' end face of the prototype blade is equal to the distance from the A-end face to the B-end face of the biomimetic ocean current generator blade. In this embodiment, L1+L2+L3+L=3.2m.

[0073] The swept-back section 2 adopts the swept-back structural elements of an owl's wing.

[0074] The swept portion 2 includes two parameters: sweep length L and sweep angle β, where 0° < β < 90°. The swept portion 2 is tilted towards the trailing edge. These two parameters determine the swept portion 2. The sweep length L is the distance between the B-end face and the second cross-section e. The sweep angle β is the angle between the pitch axis 11 of the main body 1 and the sweep curve 21 of the swept portion 2. The pitch axis 11 is the line connecting the aerodynamic centers of the airfoils at each cross-section of the main body 1, and the sweep curve 21 is the line connecting the aerodynamic centers of the airfoils at each cross-section of the swept portion 2. In this embodiment, the aerodynamic center of each airfoil cross-section is located at one-quarter of the airfoil chord length.

[0075] As can be seen from the above, each sweep length L can be combined with multiple sweep angles β to form multiple sets of sweep structure parameters.

[0076] Step S5: Obtain the torque T of the impeller of the prototype blade and each biomimetic ocean current generator blade through numerical simulation.

[0077] In this embodiment, Fluent software is used for modeling and numerical simulation, including the following steps:

[0078] Step S51: Based on the CFD numerical simulation method, models of the ocean current generator blades and prototype blades are established using fluid simulation software.

[0079] Step S52: Use fluid simulation software to mesh the two models established in step S51.

[0080] Step S53: Solve the Fluent equation for the two models after meshing in step S52 to obtain the value of the impeller torque T for each calculation.

[0081] In the solution process of step S53, the boundary conditions are as follows: inlet boundary: velocity-inlet, outlet boundary: pressure-out, blade surface: wall, and the interface between the rotating and stationary domains: INTERFACE. In this embodiment, the solution method is the coupled algorithm.

[0082] Step S6: Calculate and compare the power coefficient C of the prototype blade. P and the power coefficient C of each of the biomimetic ocean current generator blades P ,

[0083]

[0084] A = πR 2

[0085]

[0086] Where ω represents the angular velocity of the impeller; ρ represents the density of the fluid; A represents the swept area of ​​the rotor; R represents the distance between the center point O1 of the hub g and the intersection point O2 of the swept curve 21 and the end face of B; U ∞ Indicates the velocity of the inlet ocean current. ω and U ∞ Different values ​​can be selected during calculation based on the actual situation. For the prototype blade, β = 0.

[0087] Power factor C P This represents the efficiency with which an ocean current generator converts ocean current energy into mechanical energy. Clearly, the power coefficient C... P The larger the value, the better the performance of the ocean current generator.

[0088] Step S7: When the power coefficient of the biomimetic ocean current generator blade is greater than that of the prototype blade, the biomimetic ocean current generator blade can be selected as the final biomimetic ocean current generator blade.

[0089] As can be seen from the above, based on the same prototype blade, each type of biomimetic ocean current generator blade is determined by a combination of the sweep angle β and the sweep length L. The calculations above show that, with the sweep length L remaining constant, the power coefficient C increases with the increase of the sweep angle β. P The trend is that it first increases and then decreases. When the sweep angle β increases to a certain value, the power coefficient C of the biomimetic ocean current generator blade... P It will be lower than the power coefficient C of the prototype blade. P .

[0090] In this embodiment, the power coefficient C is calculated for each of the four sweep lengths L. P Greater than the prototype blade power coefficient C P The range of the sweep angle β of the biomimetic ocean current generator blades is shown in Table 3.

[0091] Table 3 Power Coefficient C P The sweep angle range and sweep length of biomimetic ocean current generator blades larger than those of the prototype blades

[0092] Sweep length L (m) 0.272 0.544 1.088 1.36 Swipe angle β (°) 0～47.8 0～45.31 0～45.31 0～42.59

[0093] In this embodiment, based on the prototype blade, the calculated optimal design parameters are: sweep length L = 0.544 m and sweep angle β = 28.88°. Under these optimal design parameters, the corresponding power coefficient C of the biomimetic ocean current generator blade is... P The larger value is within the range shown in Table 3.

[0094] In practical applications, even if the incoming flow velocity remains constant, the impeller speed will change if the direction of the incoming flow changes. Alternatively, if the incoming flow drives the impeller to rotate too fast, resistance may be artificially increased to reduce the impeller speed as needed. In other words, the impeller speed may vary even with a constant incoming flow velocity. Therefore, to predict the impeller performance at different tip speed ratios, or impeller rotational angular velocities ω, the power coefficients of a prototype blade and a biomimetic ocean current generator blade with a sweep length L = 0.544 m and a sweep angle β = 28.88° based on the prototype blade were calculated and compared. Figure 9 The figure shows a comparison of the power coefficients of the prototype blade in this embodiment and the biomimetic ocean current generator blade based on the aforementioned prototype blade, with a sweep length L = 0.544 m and a sweep angle β = 28.88°. Considering blade cavitation, at an ocean current velocity of 1.2 m / s, i.e., U... ∞ At a speed of 1.2 m / s, the power coefficient of the biomimetic ocean current generator blade is higher than that of the prototype blade under different impeller rotational angular velocities ω, or different tip speed ratios. Specifically, at a tip speed ratio of 3.35, the power coefficient of the biomimetic ocean current generator blade increases by 9.75% compared to the prototype blade.

[0095] In numerical simulations, blade calculations can simply consider the turbulent flow during impeller rotation and solve for it by adding turbulence equations. However, for large ocean current generator blades, cavitation inevitably occurs during rotation, so cavitation needs to be considered. This scheme adds a cavitation model along with the turbulence equations, resulting in calculations that better reflect reality.

[0096] Furthermore, when ocean current generator blades rotate, the speed is highest at the blade tip, which is also the region where cavitation occurs most severely. The condition for cavitation to occur on the blade surface is that the pressure on the blade surface is lower than the saturated vapor pressure of the liquid at the current temperature. Therefore, it can be said that the higher the pressure on the blade surface, the less likely cavitation will occur. Figure 10 As shown, when the blade rotates, the velocity V1 at the swept section 2 decomposes into V3 parallel to the swept curve 21 and V2 perpendicular to the swept curve 21. The value of V2 is less than V1. According to Bernoulli's equation, a lower velocity results in higher pressure. Therefore, the pressure at the swept section 2 of the biomimetic blade is greater than that of the prototype blade, a result consistent with numerical studies. Thus, the described biomimetic ocean current generator blade exhibits a certain degree of cavitation resistance compared to the prototype blade.

[0097] Cavitation is a phenomenon that often occurs with the rotation of underwater machinery. The process of cavitation is also called a phase change process, in which the liquid transforms into water vapor, which is referred to as cavitation bubbles in this context.

[0098] Finally, it is necessary to state that the above embodiments are only used to further illustrate the technical solution of the present invention in detail, and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A design method for biomimetic ocean current generator blades based on owl wing features, characterized in that, include Step S1: Obtain the prototype blade design parameters; Step S2: Calculate and select at least one sweep length L; Step S3: Select multiple sweep angles β within the range of 0~90°; Step S4: Establish a prototype blade model, using a sweep length L and a sweep angle β as a set of sweep structure parameters to obtain multiple sets of sweep structure parameters, and establish multiple biomimetic ocean current generator blade models based on the prototype blade and each set of sweep structure parameters. Step S5: Calculate the torque T of the impeller of the prototype blade and each biomimetic ocean current generator blade using numerical simulation methods; Step S6: Calculate and compare the power coefficient C of the prototype blade. P and the power coefficient C of each of the biomimetic ocean current generator blades P ; Step S7: When the power coefficient of the biomimetic ocean current generator blade is greater than that of the prototype blade, this biomimetic ocean current generator blade can be selected as the final biomimetic ocean current generator blade. The distance between the root end face and the tip end face of the prototype blade is equal to the distance between the root end face and the tip end face of the biomimetic ocean current generator blade. The biomimetic ocean current generator blade includes a main body (1) and a swept portion (2), which are integrally connected. The interface between the main body (1) and the swept portion (2) is a second section (e). The part between the second section (e) and the end face of the tip of the biomimetic ocean current generator blade is the swept portion (2). The distance between the second section (e) and the end face of the tip of the biomimetic ocean current generator blade is the swept length (L). Suppose that the prototype blade has a third section (s), the third section (s) and the tip end face of the prototype blade are arranged parallel to each other, the distance between the third section (s) and the tip end face of the prototype blade is the sweep length (L), and the structure of the main body (1) is the same as the structure between the tip end face of the prototype blade and the third section (s).

2. The design method according to claim 1, characterized in that: In step S3, multiple sweep angles β are selected by searching using the binary search method.

3. The design method according to claim 1, characterized in that: In step S2, the formula for calculating and selecting the sweep length L is L = L4n1 / n2, where n1 and n2 are natural numbers, 1≤n1≤n2, n2=5~20, and L4 is the distance between the end face of the tip of the prototype blade and the cross section where the most concave part of the trailing edge is located.

4. The design method according to claim 1, characterized in that: In step S6, ； ； ； The plurality of blades are connected to the hub (g) to form an impeller, wherein, This indicates the angular velocity of the impeller. Indicates the density of the fluid; R represents the swept area of ​​the rotor; R represents the distance between the center point (O1) of the hub (g) and the intersection point (O2) of the sweep curve (21) and the end face of the blade tip. The inlet current velocity is indicated by the sweep curve (21), which is the line connecting the aerodynamic centers of the airfoils of each section of the swept part (2). L1 is the distance between the center point (O1) of the hub (g) of the impeller and the end face of the blade root. L2 is the distance between the end face of the blade root and the section where the trailing edge is most concave. For the prototype blade, L3 is the distance from the section where the trailing edge is most concave to the third section (s). For the biomimetic ocean current generator blade, L3 is the distance from the section where the trailing edge is most concave to the second section (e).

5. The design method according to claim 1, characterized in that: The distance between the root end face and the tip end face of the biomimetic ocean current generator blade is 2.86m.

6. The design method according to claim 4 or 5, characterized in that: When the sweep length L = 0.272m, the sweep angle β = 0~47.8°; when the sweep length L = 0.544m, the sweep angle β = 0~45.31°; when the sweep length L = 1.088m, the sweep angle β = 0~45.31°; when the sweep length L = 1.36m, the sweep angle β = 0~42.59°.

7. The design method according to claim 6, characterized in that: The sweep length L = 0.544m. .

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