Blade design method, blade and air driving device

Abstract

This invention provides a wind turbine blade design method, a wind turbine blade, and an air-driven device. The method includes: obtaining basic design parameters of the wind turbine blade; defining dimensionless spanwise coordinates; defining a camber curve based on the blade root camber value, blade tip camber value, the rate of change of the blade root camber curve with respect to the dimensionless spanwise coordinate t, and the rate of change of the blade tip camber curve with respect to the dimensionless spanwise coordinate t; defining a sweep curve based on the blade root sweep value, blade tip sweep value, the rate of change of the blade root sweep curve with respect to the dimensionless spanwise coordinate t, and the rate of change of the blade tip sweep curve with respect to the dimensionless spanwise coordinate t, wherein both the camber curve and the sweep curve are cubic polynomial functions; and generating a three-dimensional model of the wind turbine blade. This invention achieves secondary distribution adjustment of spanwise load by controlling endpoint values ​​and endpoint slopes. Fewer control parameters simplify blade optimization design, resulting in a smoother pressure gradient change along the spanwise direction, effectively suppressing airflow separation, reducing wake vortices, and improving airflow and static pressure efficiency.

Description

Technical Field

[0001] This invention belongs to the field of wind turbine blade design technology, specifically relating to a wind turbine blade design method, a wind turbine blade, and an air-driven device. Background Technology

[0002] In the field of wind turbines, fans and aerodynamic equipment, the aerodynamic performance of the blades directly determines the efficiency, noise level and operational stability of the equipment. The aerodynamic performance of the blades depends on the curvature of the blades in space.

[0003] Traditional wind turbine blade designs often use straight lines or simple curved stacking, resulting in simple lines, too many parameters, and difficulty in optimization.

[0004] For example, one existing design method is to design N sections along the blade spanwise, where N is 3 to 15. Each section is designed with a separate spatial position, resulting in a total of 3N section point parameters that are independent of each other. Each section also requires a separate blade chord length, with a total number greater than 4N. Another method is to use spline fitting, which requires setting more than 3 fitting points. Each point needs to be set with a separate spatial position, chord length, and curvature, resulting in a total number of parameters greater than 15. Obviously, the number of parameters is too high. Summary of the Invention

[0005] Therefore, the present invention provides a fan blade design method, a fan blade and an air drive device, which can overcome the shortcomings of the fan blade design in the related technology, which uses straight lines or simple arc stacking, with simple line forms and too many parameters that are not conducive to optimization.

[0006] To address the above problems, the present invention provides a wind turbine blade design method, comprising the following steps:

[0007] Obtain the basic design parameters of the wind turbine blades, including the target total length R of the blades and the target radius r of the hub. hub The number of blades and the axial thickness of the hub;

[0008] Define dimensionless span coordinates: , ;

[0009] Based on leaf root curvature value Leaf tip curvature value Rate of change of leaf root curvature curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip curvature curve with respect to the dimensionless span coordinate t Define the camber curve based on the blade root sweep value. Leaf tip sweep value The rate of change of the leaf root sweep curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip sweep curve with respect to the dimensionless span coordinate t Define the sweep curve, where both the curvature curve and the sweep curve are cubic polynomial functions;

[0010] A three-dimensional model of the wind turbine blades is generated based on the defined curvature curve, sweep curve, and basic design parameters.

[0011] In some implementations...

[0012] The curvature curve is as follows:

[0013] ;

[0014] The sweep curve is:

[0015] .

[0016] In some implementations...

[0017] 0≤ ≤0.02 L root L is the chord length at the leaf base. root =0.08R~0.25R, 0.01 ≤ ≤0.08 L tip L is the chord length at the leaf tip. tip =0.03R~0.1R, 0≤ ≤2 -1.5 ≤ ≤1.5 ;

[0018] E0=0, | |≤0.15 , , .

[0019] In some implementations...

[0020] When 0 < C1 ≤ 30, 1.5C1 < S0 ≤ 2C1; when 30 < C1 ≤ 70, 0.5C1 < S0 ≤ 1.5C1; when 70 ≤ C1, 0 < S0 ≤ 0.5C1; or,

[0021] , .

[0022] In some implementations...

[0023] After generating the 3D model of the wind turbine blades, the following steps are also included:

[0024] Based on the three-dimensional model of the wind turbine blades, the corresponding theoretical performance parameters are obtained. If these parameters do not meet the design requirements, the blade root curvature value is adjusted. Leaf tip curvature value Rate of change of leaf root curvature curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip curvature curve with respect to the dimensionless span coordinate t Leaf root sweep value Leaf tip sweep value The rate of change of the leaf root sweep curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip sweep curve with respect to the dimensionless span coordinate t L root and / or L tip The value of at least one of them is selected until the theoretical performance parameters corresponding to the generated three-dimensional model of the wind turbine blade meet the design requirements.

[0025] In some implementations...

[0026] The theoretical performance parameters include at least one of the following: rated speed, design wind speed or flow rate, pressure rise or power, and stress.

[0027] In some implementations...

[0028] After the theoretical performance parameters corresponding to the three-dimensional model of the wind turbine blade meet the design requirements, a wind turbine blade sample is prepared based on the three-dimensional model of the wind turbine blade, and the measured performance parameters corresponding to each theoretical performance parameter are measured based on the prepared wind turbine blade sample.

[0029] In some implementations...

[0030] The peak point of the curvature curve is The peak point of the sweep curve is , | |≥0.15R.

[0031] In some implementations...

[0032] The generation of a 3D model of the wind turbine blades based on the defined camber curve, sweep curve, and basic design parameters specifically includes:

[0033] Using t as a reference, multiple control sections are selected at different spanwise positions along the direction from the blade root to the blade tip, and each control section defines a basic airfoil;

[0034] Calculate the camber and sweep values ​​corresponding to the t value at the current spanwise position, and superimpose the aforementioned camber and sweep values ​​with the original x and z coordinates of the midpoint of the blade chord length at the current spanwise position to obtain the coordinates of the midpoint of the chord length at the current spanwise position.

[0035] The airfoil is generated into a continuous blade surface and solid model according to the spanwise position in ascending order of t, and the basic design parameters are combined to obtain the three-dimensional model of the wind turbine blade.

[0036] The present invention also provides a wind turbine blade, which is designed and formed using the wind turbine blade design method described above.

[0037] The present invention also provides an air-driven device, including a fan blade, wherein the fan blade is the aforementioned fan blade.

[0038] The wind turbine blade design method, wind turbine blade, and air drive device provided by this invention have the following beneficial effects:

[0039] On the one hand, based on the blade root curvature value Leaf tip curvature value Rate of change of leaf root curvature curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip curvature curve with respect to the dimensionless span coordinate t Define the camber curve based on the blade root sweep value. Leaf tip sweep value The rate of change of the leaf root sweep curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip sweep curve with respect to the dimensionless span coordinate t By defining a sweep curve and controlling the endpoint values ​​and slopes, the secondary distribution of spanwise loads can be adjusted. Fewer control parameters simplify blade optimization design; only a few key parameters of the curve need to be determined to fully define the three-dimensional spatial morphology of the blade, eliminating the need for complex piecewise fitting. This greatly reduces the difficulty and production cost of 3D modeling (e.g., CAD modeling) and mold processing. On the other hand, both the defined camber and sweep curves are cubic polynomial functions, with their second derivatives being linear functions, meaning the pressure gradient changes linearly along the spanwise direction. This smooth transition makes the pressure gradient change along the blade's spanwise direction more gradual, effectively suppressing airflow separation and reducing wake vortices, thereby significantly improving airflow and static pressure efficiency. The cubic polynomial function also allows for independent control of the rate of change at the blade root and tip, enabling precise adjustment of the blade load growth rate. This can prevent local overload in the blade root region from causing airflow separation and reduce tip vortex intensity in the blade tip region, increasing blade efficiency. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0041] Figure 1This is a schematic diagram of the steps of the wind turbine blade design method in an embodiment of the present invention;

[0042] Figure 2 This is a structural schematic diagram of a cross-section of a blade at a spanwise position in an embodiment of the present invention;

[0043] Figure 3 This is a front view (axial projection) of the fan blade in an embodiment of the present invention.

[0044] Figure 4 yes Figure 3 A front view of half of the wind turbine blades, showing the curvature curve;

[0045] Figure 5 yes Figure 3 A side view of half of the wind turbine blades, showing the sweep curve;

[0046] Figure 6 This is a flowchart illustrating the design process of a fan blade design method according to an embodiment of the present invention.

[0047] The attached figures are labeled as follows:

[0048] 100. Blade; 101. Hub. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0051] 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° or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0052] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0053] See also Figures 1 to 5 As shown, according to an embodiment of the present invention, a wind turbine blade design method is provided, comprising the following steps:

[0054] Obtain the basic design parameters of the wind turbine blades, including the target total length R of the blade 100 and the target radius r of the hub 101. hub The number of blades 100 and the axial thickness of the hub 101;

[0055] Define dimensionless span coordinates: , ;

[0056] Based on leaf root curvature value Leaf tip curvature value Rate of change of leaf root curvature curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip curvature curve with respect to the dimensionless span coordinate t Define the camber curve based on the blade root sweep value. Leaf tip sweep value The rate of change of the leaf root sweep curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip sweep curve with respect to the dimensionless span coordinate t Define the sweep curve. Both the camber curve and the sweep curve are cubic polynomial functions. It is understood that the aforementioned camber curve is located in the plane of rotation of the blade 100, and the sweep curve is located in a plane perpendicular to the plane of rotation of the blade 100.

[0057] The three-dimensional model of the wind turbine blade is generated based on the defined camber curve, sweep curve, and basic design parameters. It is understood that the generation of the aforementioned three-dimensional model of the wind turbine blade can be achieved with the help of a corresponding software platform with three-dimensional design functions. The specific software platform can be reasonably selected according to actual needs, and this invention does not impose any special limitations on it.

[0058] In this technical solution, on the one hand, it is based on the blade root curvature value. Leaf tip curvature value Rate of change of leaf root curvature curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip curvature curve with respect to the dimensionless span coordinate t Define the camber curve based on the blade root sweep value. Leaf tip sweep value The rate of change of the leaf root sweep curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip sweep curve with respect to the dimensionless span coordinate t By defining a sweep curve and controlling the endpoint values ​​and slopes, the secondary distribution of spanwise loads can be adjusted. Fewer control parameters simplify blade optimization design; only a few key parameters of the curve need to be determined to fully define the three-dimensional spatial morphology of the blade, eliminating the need for complex piecewise fitting and significantly reducing the difficulty and production cost of 3D modeling (e.g., CAD modeling) and mold processing. Furthermore, both the defined camber and sweep curves are cubic polynomial functions, with their second derivatives being linear functions, meaning the pressure gradient changes linearly along the spanwise direction, resulting in a smooth transition. This makes the pressure gradient change along the blade's spanwise direction more gradual, effectively suppressing airflow separation and reducing wake vortices, thereby significantly improving airflow and static pressure efficiency. The cubic polynomial function also allows for independent control of the rate of change at the blade root and tip, enabling precise adjustment of the blade load growth rate. This avoids local overload leading to airflow separation in the blade root region and reduces tip vortex intensity in the blade tip region, increasing blade efficiency.

[0059] In some embodiments, the curvature curve is:

[0060] ;

[0061] The sweep curve is:

[0062] .

[0063] Unlike quadratic polynomials where the curvature remains constant along the span, cubic polynomials allow for positive and negative variations in curvature. This allows for different curvature settings in different blade regions, such as a small curvature at the blade root to ensure the structural strength of the blade root, a large curvature in the middle of the blade to generate greater lift, and a small curvature at the blade tip to maintain consistent tip vortices.

[0064] Where, 0≤ ≤0.02 L root L is the chord length at the leaf base. root =0.08R~0.25R, 0.01 ≤ ≤0.08 L tip L is the chord length at the leaf tip. tip =0.03R~0.1R, 0≤ ≤2 -1.5 ≤ ≤1.5 E0=0, | |≤0.15 , , .

[0065] C0 is limited to the chord length L at the leaf root. root Within the aforementioned range, taking a positive value can reduce root turbulence; C1 can be adjusted according to the blade force value and distribution. Taking a positive value for S0 indicates that the curvature increases from the blade root. When S1 is close to 0, the change in blade tip curvature is gradual, which is beneficial to suppress the formation of blade tip vortices.

[0066] This is the sweep value at the blade root, which is usually taken as 0, but can also be set to a non-zero value depending on the axial installation position of the blade in the hub. This represents the blade tip sweep value; a positive value indicates backward sweep towards the air intake direction, and a negative value indicates forward sweep towards the air outlet direction. The rate of change of the sweep curve at the leaf root. This represents the rate of change of the leaf tip sweep curve.

[0067] when = =0, >0, the blades are symmetrically swept back, the tip vortex intensity is small, and the blade torque is small; when = =0, <0, the blades sweep forward symmetrically, the blade tip stall is delayed, and the wind volume of the fan blades is large;

[0068] In some implementations, when 0 < C1 ≤ 30, 1.5C1 < S0 ≤ 2C1; when 30 < C1 ≤ 70, 0.5C1 < S0 ≤ 1.5C1; and when 70 ≤ C1, 0 < S0 ≤ 0.5C1.

[0069] or, =2 - , =2 - This makes the expression for the cubic polynomial function of the aforementioned curvature curve as follows: The parabola is a special case of the aforementioned cubic polynomial function, which can be used in the same function structure when designing wind turbine blades.

[0070] It is understandable that the aforementioned cubic polynomial functions for the curvature and sweep curves include the quadratic polynomial case, where the absolute value of the coefficients of the cubic terms is less than 10. -5 When the leaf tip chord length is doubled, it is considered as an equivalent quadratic curve.

[0071] The dimensions of the aforementioned curvature and sweep values ​​are consistent with the dimensions of the corresponding R. For example, if the dimension of R is mm, then the dimensions of the aforementioned curvature and sweep values ​​are also mm. If the dimension of R is cm, then the dimensions of the aforementioned curvature and sweep values ​​are also cm.

[0072] In some implementations, the process of generating the 3D model of the wind turbine blades further includes:

[0073] Based on the three-dimensional model of the wind turbine blades, the corresponding theoretical performance parameters are obtained. For example, theoretical performance parameters such as power and air volume are calculated through CFD simulation, and theoretical performance parameters such as blade stress under the combined action of centrifugal force and aerodynamic pressure are verified using the finite element method. If the design requirements are not met, the blade root curvature value is adjusted. Leaf tip curvature value Rate of change of leaf root curvature curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip curvature curve with respect to the dimensionless span coordinate t Leaf root sweep value Leaf tip sweep value The rate of change of the leaf root sweep curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip sweep curve with respect to the dimensionless span coordinate t L root and / or L tip The value of at least one of the following is selected until the theoretical performance parameters corresponding to the generated three-dimensional model of the wind turbine blades meet the design requirements. The aforementioned theoretical performance parameters include at least one of rated speed, design wind speed or flow rate, pressure rise or power, and stress, and the specific selection can be made reasonably according to actual needs.

[0074] For example, when the design wind speed or flow rate does not meet the requirements, adjust the blade tip camber C1; when the pressure rise is not met, adjust the blade root camber change rate S0; when the power does not meet the required value, adjust the blade tip camber value S1; when the blade root load is too large, adjust the blade root sweep E0 and the blade root sweep change rate T0; when the blade tip load deformation is too large, adjust the blade tip sweep value E1.

[0075] In some implementations, after the theoretical performance parameters corresponding to the three-dimensional model of the wind turbine blade meet the design requirements, a wind turbine blade sample is prepared based on the three-dimensional model of the wind turbine blade, and the measured performance parameters corresponding to each theoretical performance parameter are measured based on the prepared wind turbine blade sample, so as to further verify the accuracy of the theoretical design.

[0076] The cubic polynomial function curve produces extreme points in the spanwise region of the blade, and the local aerodynamic load increases with increasing camber, while concentrating in regions with large sweep rates. The peak point of the camber curve is... The peak point of the sweep curve is , | |≥0.15R, can disperse the concentrated area of ​​blade load, and at the same time disperse airflow vortices.

[0077] In some implementations, generating a three-dimensional model of the wind turbine blades based on the defined camber curve, sweep curve, and basic design parameters specifically includes:

[0078] Using t as a reference, select multiple control sections at different spanwise positions along the direction from the blade root to the blade tip of the blade 100. Each control section defines a basic airfoil. The number of control sections can generally be 5-15.

[0079] Calculate the camber and sweep values ​​corresponding to the t value at the current spanwise position, and superimpose the aforementioned camber and sweep values ​​with the original x and z coordinates of the midpoint of the blade chord length at the current spanwise position to obtain the coordinates of the midpoint of the chord length at the current spanwise position.

[0080] The airfoil is generated into a continuous blade surface and solid model according to the spanwise position in an increasing order of t, and the basic design parameters are combined. Preferably, the blade tip and blade root are transitioned to obtain the three-dimensional model of the wind turbine blade.

[0081] The technical solution of the present invention is further described below:

[0082] This invention provides an efficient, multi-parameter method for wind turbine blade design and simulation. Using the midpoint of the airfoil chord length at each blade cross-section as the stacking reference point, both the camber curve in the plane of rotation and the sweep curve perpendicular to the plane of rotation are cubic polynomial functions (in special cases, quadratic parabolas). The polynomial coefficients of the two curves are set independently, and the quadratic distribution of spanwise loads is adjusted by controlling the endpoint values ​​and endpoint slopes. See also... Figure 6 As shown, the specific implementation method is as follows:

[0083] Step 101, determine the design conditions and basic parameters: based on the application scenario of the wind turbine blades (such as wind power generation, axial flow ventilation, compressors, drone propellers, etc.), determine the rated speed, design wind speed or flow rate, pressure rise or power requirements.

[0084] The camber and sweep curves of the wind turbine blades are both cubic polynomial functions of the spanwise position r, and the two curves are set independently; the total blade length is R (i.e., the aforementioned target total length R), and the hub radius is... (that is, the aforementioned target radius r) hub ),like Figure 3 As shown.

[0085] Step 102, define dimensionless spanning coordinates: , t=0 corresponds to the blade root section, t=1 corresponds to the blade tip section, see also [link to relevant documentation]. Figures 3 to 5 As shown, the X-axis runs along the blade chord direction from the leading edge to the trailing edge (see...). Figure 2 As shown in the diagram, the Y-axis is perpendicular to the chord line, and the Z-axis is perpendicular to the plane of rotation and coincides with the axis of rotation, pointing in the direction of airflow into the blades. A schematic diagram of the blade airfoil chord length is shown below. Figure 2 The airfoil stacking method of this application involves stacking the airfoils along the blade span with the center point of the blade chord. See the diagrams for camber and sweep stacking, respectively. Figure 4 and Figure 5 As shown.

[0086] Step 103, Define the curvature curve

[0087]

[0088] in , , , For real numbers, when When =0, it is either a parabola or a straight line.

[0089] The coefficients are determined based on the endpoint values ​​and endpoint slopes:

[0090]

[0091]

[0092]

[0093]

[0094] in, This is the blade root curvature value, and the unit is consistent with the unit of R. This is the tip curvature value, and the unit is consistent with that of R. Let be the rate of change of the leaf root curvature curve with respect to the dimensionless coordinate t. (Dimensionless) Let be the rate of change of the tip curvature curve with respect to the dimensionless coordinate t, which is dimensionless.

[0095] Four parameters uniquely determine a cubic polynomial:

[0096] , , = , ;

[0097] To reduce root turbulence, a positive value for the leaf root chord length is used, which is related to the leaf root chord length. The relevant scope is =0~0.02 ; It can be adjusted according to the stress value and distribution on the blade, and the chord length of the leaf tip. The relevant scope is =0.01 ~0.08 A positive value indicates that the curvature increases from the blade root, and the range is... =0~2 ;

[0098] .

[0099] When the value is close to 0, the tip camber changes gradually, which is conducive to the formation of uniform tip vortices, and the range is [missing value]. =-1.5 ~1.5 .

[0100] The cubic polynomials mentioned above include the parabola as a special case. =2 - , =2 - The design of wind turbine blades can be performed within the same function structure. Specifically, when... =2( - ), =2( - When bringing in) The expression yields ,at this time The expression is a parabola.

[0101] Step 104, Define the glancing curve

[0102]

[0103] in , , , For real numbers, when When =0, it is either a parabola or a straight line.

[0104]

[0105]

[0106]

[0107]

[0108] in, This is the sweep value at the blade root, which is usually taken as 0, but can also be set to a non-zero value depending on the axial installation position of the blade in the hub. This represents the blade tip sweep value, with positive values ​​indicating backward sweep towards the airflow direction and negative values ​​indicating forward sweep towards the airflow direction. The range is | |≤0.15 ; Let |T0| be the rate of change of the sweep curve at the leaf root, and |T0| ≤ 0.2|E1||. Let |T1| be the rate of change of the leaf tip sweep curve, and |T1| ≤ 0.3|E1|.

[0109] Four parameters uniquely determine a cubic polynomial:

[0110] ;

[0111] when = =0, >0, the blades are symmetrically swept back, the tip vortex intensity is small, and the blade torque is small; when = =0, <0, the blades sweep forward symmetrically, the blade tip stall is delayed, and the wind volume of the fan blades is large;

[0112] The cubic polynomial functions for curvature and sweep curves described above include the quadratic polynomial case, where the absolute value of the coefficients of the cubic terms is less than 10. -5 When the leaf tip chord length is doubled, it is considered as an equivalent quadratic curve.

[0113] The cubic curve will produce extreme points in the spanwise region of the blade, and the local aerodynamic load increases with the increase of camber, while concentrating in the region with a large rate of change of sweep angle. (Calculation...) and The solution of 0 yields the peak points of curvature and sweep. and Settings | |≥0.15R, disperses the concentrated area of ​​blade load, and at the same time disperses airflow vortices.

[0114] Step 105: Generate a three-dimensional blade by superimposing the camber and sweep values ​​onto the midpoint of the chord length of each airfoil section.

[0115] Step 1051: Divide the blade sections. Using t as the reference, select 5 to 15 control sections at spanwise positions such as t=0, 0.1, 0.2, ..., and define a basic airfoil (NACA series standard airfoils) for each section.

[0116] Step 1052: Overlay the curvature and sweep, and calculate the corresponding t value. and The optimized (i.e., the redesigned) and The x and z coordinates superimposed on the midpoint of the chord length;

[0117] For the coordinates of the midpoint M(t) of the chord length at point t, the optimized coordinates are... The coordinates before optimization, i.e., the initial coordinates The relationship is

[0118] ,

[0119] in Because the spanning position remains unchanged, =0, .

[0120] Step 1053: Generate the three-dimensional blade. Generate continuous blade surfaces and solid models for all airfoils according to their spanwise positions in ascending order of t. Process the transition between the blade tip and the blade root.

[0121] Step 106: Aerodynamic simulation verification and iteration. Perform CFD simulation to calculate the power, air volume, etc. of the scheme. Use the finite element method to verify the stress under the combined action of centrifugal force and aerodynamic pressure. If the simulation results do not meet the requirements, adjust the curve parameters and repeat steps 103 to 105.

[0122] Step 107, Sample Verification: Using the 3D model generated by the above method, manufacture wind turbine blade samples and conduct actual tests to verify the feasibility of the scheme.

[0123] The camber and sweep curve expressions described in this invention can be used for axial flow blades, compressor blades, fan blades, wind turbine blades, etc.

[0124] According to an embodiment of the present invention, a wind blade is also provided, which is designed and formed using the wind blade design method described above. Specifically, the blade of the aforementioned wind blade can be an axial flow blade, a compressor blade, a fan blade, a wind power generation blade, etc.

[0125] According to an embodiment of the present invention, an air drive device is also provided, including a fan blade, wherein the fan blade is the aforementioned fan blade, and the aforementioned air drive device may be, for example, an axial flow fan, a centrifugal fan, a compressor, etc.

[0126] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0127] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A method for designing wind turbine blades, characterized in that, Includes the following steps: Obtain the basic design parameters of the wind turbine blades, including the target total length R of the blades (100) and the target radius r of the hub (101). hub The number of blades (100) and the axial thickness of the hub (101); Define dimensionless span coordinates: , ; Based on leaf root curvature value Leaf tip curvature value Rate of change of leaf root curvature curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip curvature curve with respect to the dimensionless span coordinate t Define the camber curve based on the blade root sweep value. Leaf tip sweep value The rate of change of the leaf root sweep curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip sweep curve with respect to the dimensionless span coordinate t Define the sweep curve, where both the curvature curve and the sweep curve are cubic polynomial functions; A three-dimensional model of the wind turbine blades is generated based on the defined curvature curve, sweep curve, and basic design parameters.

2. The wind turbine blade design method according to claim 1, characterized in that, The curvature curve is as follows: ； The sweep curve is: 。 3. The wind turbine blade design method according to claim 2, characterized in that, 0≤ ≤0.02 L root L is the chord length at the leaf base. root =0.08R~0.25R, 0.01 ≤ ≤0.08 L tip L is the chord length at the leaf tip. tip =0.03R~0.1R, 0≤ ≤2 -1.5 ≤ ≤1.5 ; E0=0，| |≤0.15 ， ， 。 4. The wind turbine blade design method according to claim 3, characterized in that, When 0 < C1 ≤ 30, 1.5C1 < S0 ≤ 2C1; when 30 < C1 ≤ 70, 0.5C1 < S0 ≤ 1.5C1; when 70 ≤ C1, 0 < S0 ≤ 0.5C1; or, ， 。 5. The wind turbine blade design method according to claim 3, characterized in that, After generating the 3D model of the wind turbine blades, the following steps are also included: Based on the three-dimensional model of the wind turbine blades, the corresponding theoretical performance parameters are obtained. If these parameters do not meet the design requirements, the blade root curvature value is adjusted. Leaf tip curvature value Rate of change of leaf root curvature curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip curvature curve with respect to the dimensionless span coordinate t Leaf root sweep value Leaf tip sweep value The rate of change of the leaf root sweep curve with respect to the dimensionless span coordinate t The rate of change of the leaf tip sweep curve with respect to the dimensionless span coordinate t L root and / or L tip The value of at least one of them is selected until the theoretical performance parameters corresponding to the generated three-dimensional model of the wind turbine blade meet the design requirements.

6. The wind turbine blade design method according to claim 5, characterized in that, The theoretical performance parameters include at least one of the following: rated speed, design wind speed or flow rate, pressure rise or power, and stress.

7. The wind turbine blade design method according to claim 5, characterized in that, After the theoretical performance parameters corresponding to the three-dimensional model of the wind turbine blade meet the design requirements, a wind turbine blade sample is prepared based on the three-dimensional model of the wind turbine blade, and the measured performance parameters corresponding to each theoretical performance parameter are measured based on the prepared wind turbine blade sample.

8. The wind turbine blade design method according to claim 2, characterized in that, The peak point of the curvature curve is The peak point of the sweep curve is , | |≥0.15R.

9. The wind turbine blade design method according to claim 1, characterized in that, The generation of a 3D model of the wind turbine blades based on the defined curvature curve, sweep curve, and basic design parameters specifically includes: Based on t, multiple control sections are selected at different spanwise positions along the direction from the root to the tip of the blade (100), and each control section defines a basic airfoil; Calculate the camber and sweep values ​​corresponding to the t value at the current spanwise position, and superimpose the aforementioned camber and sweep values ​​with the original x and z coordinates of the midpoint of the blade chord length at the current spanwise position to obtain the coordinates of the midpoint of the chord length at the current spanwise position. The airfoil is generated into a continuous blade surface and solid model according to the spanwise position in ascending order of t, and the basic design parameters are combined to obtain the three-dimensional model of the wind turbine blade.

10. A wind turbine blade, characterized in that, The wind turbine blades are designed and formed using the wind turbine blade design method described in any one of claims 1 to 9.

11. An air-driven device, characterized in that, Includes a wind turbine blade, wherein the wind turbine blade is the wind turbine blade as described in claim 10.

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