Blade aerodynamic efficiency evaluation method and system, electronic device and storage medium

Abstract

The application relates to the technical field of wind turbine units, and particularly provides a blade aerodynamic efficiency evaluation method and system, an electronic device and a storage medium, and aims to solve the problem of evaluating the aerodynamic efficiency of a flexible blade. To this end, the blade aerodynamic efficiency evaluation method comprises the following steps: determining a blade deformation variable in a final deformation state by using a pre-constructed aeroelastic model and a blade tip loss coefficient database; determining a corrected blade aerodynamic force based on the blade deformation variable in the final deformation state; determining aerodynamic data of a wind turbine based on the corrected blade aerodynamic force, wherein the aerodynamic data comprises total thrust, total torque and power; and determining an aerodynamic efficiency evaluation result of the blade based on the aerodynamic data of the wind turbine. The application can realize accurate quantification of the aerodynamic efficiency of a flexible blade, and provides theoretical support for the design and safe operation of a long-flexible blade.

Description

Technical Field

[0001] This application relates to the field of wind turbine technology, specifically to a method, system, electronic device, and storage medium for evaluating the aerodynamic efficiency of wind turbine blades. Background Technology

[0002] As the global energy structure transitions towards cleaner and lower-carbon energy, wind energy, as one of the core renewable energy sources, has become a key technological challenge for its efficient development and utilization. In recent years, wind turbines have continued to evolve towards larger and more efficient designs, with significant changes in blade design: rotor diameters have exceeded 200 meters, aspect ratios have increased to the range of 8-10, and blade structural flexibility has been greatly enhanced. While these ultra-long flexible blades can improve wind energy capture efficiency in low-wind-speed areas, they also bring serious aeroelastic coupling problems. Under complex conditions such as strong winds and turbulence, the interaction between aerodynamic loads and structural flexibility can easily induce nonlinear bending-torsional deformation in the blades, leading to the following key issues: aerodynamic performance degradation and efficiency loss; structural fatigue and increased operational risks. Therefore, how to accurately quantify the aerodynamic efficiency of flexible blades has become an urgent problem to be solved.

[0003] Accordingly, there is a need in the field for a new blade aerodynamic efficiency evaluation scheme to address the above problems. Summary of the Invention

[0004] In order to overcome the above-mentioned deficiencies, this application is made to solve, or at least partially solve, the technical problem of how to achieve accurate quantification of the aerodynamic efficiency of flexible blades.

[0005] In a first aspect, a method for evaluating the aerodynamic efficiency of a blade is provided. The method includes: determining the blade deformation under a final deformation state using a pre-constructed aeroelastic model and a blade tip loss coefficient database; determining a corrected blade aerodynamic force based on the blade deformation under the final deformation state; determining aerodynamic data of a wind turbine based on the corrected blade aerodynamic force, the aerodynamic data including total thrust, total torque, and power; and determining the aerodynamic efficiency evaluation result of the blade based on the aerodynamic data of the wind turbine.

[0006] In one technical solution of the aforementioned blade aerodynamic efficiency evaluation method, the aeroelastic model includes an aerodynamic model and a structural model, wherein the aerodynamic model is constructed based on the blade element momentum theory, and the structural model is constructed based on the geometrically precise beam theory; the blade tip loss coefficient database includes multiple sets of deformation amplitudes and corresponding blade tip loss coefficients; the step of determining the blade deformation under the final deformation state using the pre-constructed aeroelastic model and blade tip loss coefficient database includes: determining the initial deformation of the blade based on the aeroelastic model; obtaining the corresponding blade tip loss coefficient from the blade tip loss coefficient database through linear interpolation based on the initial deformation; correcting the blade tip loss factor in the aerodynamic model based on the blade tip loss coefficient corresponding to the initial deformation, iteratively updating the aerodynamic force and deformation, and determining the blade deformation under the final deformation state.

[0007] In one technical solution of the above-mentioned blade aerodynamic efficiency evaluation method, determining the initial deformation of the blade based on the aeroelastic model includes: determining the initial aerodynamic force of the blade based on the geometric parameters of the undeformed blade using the aerodynamic model; and determining the initial deformation of the blade based on the initial aerodynamic force of the blade using the structural model.

[0008] In one technical solution of the aforementioned blade aerodynamic efficiency evaluation method, the step of correcting the tip loss factor in the aerodynamic model based on the tip loss coefficient corresponding to the initial deformation, iteratively updating the aerodynamic force and deformation, and determining the blade deformation under the final deformation state includes: correcting the tip loss factor in the aerodynamic model based on the tip loss coefficient and Prandtl tip loss factor corresponding to the initial deformation; updating the aerodynamic force based on the corrected aerodynamic model to obtain the updated aerodynamic force; determining whether the relative error between the aerodynamic force before the update and the updated aerodynamic force is less than a preset threshold; if so, inputting the updated aerodynamic force into the structural model to determine the blade deformation under the final deformation state; otherwise, inputting the updated aerodynamic force into the structural model, calculating the new deformation, and repeatedly updating the aerodynamic force until the relative error between the aerodynamic force before the update and the updated aerodynamic force is less than the preset threshold.

[0009] In one technical solution of the above-mentioned blade aerodynamic efficiency evaluation method, the step of determining the corrected blade aerodynamic force based on the blade deformation under the final deformation state includes: obtaining the blade tip loss coefficient corresponding to the blade deformation under the final deformation state from the blade tip loss coefficient database by linear interpolation based on the blade deformation under the final deformation state; and determining the corrected blade aerodynamic force based on the blade tip loss coefficient corresponding to the blade deformation under the final deformation state, considering the change in projected area caused by deformation, wherein the corrected blade aerodynamic force includes the thrust and torque at each blade element position in the rotor plane.

[0010] In one technical solution of the above-mentioned blade aerodynamic efficiency evaluation method, the step of determining the aerodynamic data of the wind turbine based on the corrected blade aerodynamic force includes: integrating the thrust and torque at each blade element position in the rotor plane along the blade span to obtain the total thrust and total torque of the wind turbine; and determining the power of the wind turbine based on the total torque and rotor speed.

[0011] In one technical solution of the above-mentioned blade aerodynamic efficiency evaluation method, determining the aerodynamic efficiency evaluation result of the blade based on the aerodynamic data of the wind turbine includes: determining the wind energy utilization coefficient based on the power of the wind turbine; determining the thrust coefficient based on the total thrust of the wind turbine; determining the torque coefficient based on the total torque of the wind turbine; and using the wind energy utilization coefficient, the thrust coefficient, and the torque coefficient as the aerodynamic efficiency evaluation result.

[0012] In a second aspect, a blade aerodynamic efficiency evaluation system is provided, the system comprising: a blade deformation determination module, used to determine the blade deformation under the final deformation state using a pre-built aeroelastic model and a blade tip loss coefficient database; a blade aerodynamic force determination module, used to determine the corrected blade aerodynamic force based on the blade deformation under the final deformation state; an aerodynamic data determination module, used to determine the aerodynamic data of the wind turbine based on the corrected blade aerodynamic force, the aerodynamic data including total thrust, total torque and power; and an aerodynamic efficiency evaluation result determination module, used to determine the aerodynamic efficiency evaluation result of the blade based on the aerodynamic data of the wind turbine.

[0013] In a third aspect, an electronic device is provided, comprising at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program, which, when executed by the at least one processor, implements the method described in any of the above-described technical solutions for the blade aerodynamic efficiency evaluation method.

[0014] In a fourth aspect, a computer-readable storage medium is provided, wherein a plurality of program codes are stored therein, the program codes being adapted to be loaded and run by a processor to perform the method described in any of the above-described technical solutions for the blade aerodynamic efficiency evaluation method.

[0015] The above-described technical solutions of this application have at least one or more of the following beneficial effects:

[0016] The blade aerodynamic efficiency evaluation method provided in this application includes: determining the blade deformation under the final deformation state using a pre-constructed aeroelastic model and a blade tip loss coefficient database; determining the corrected blade aerodynamic force based on the blade deformation under the final deformation state; determining the aerodynamic data of the wind turbine based on the corrected blade aerodynamic force, the aerodynamic data including total thrust, total torque, and power; and determining the aerodynamic efficiency evaluation result of the blade based on the aerodynamic data of the wind turbine. This application analyzes the dynamic response characteristics of flexible blades under different wind speeds and turbulent conditions, thereby evaluating the aerodynamic efficiency and structural performance of the blades. This can effectively optimize the design of flexible blades, improve the aerodynamic efficiency and aeroelastic stability of the blades, and reduce the failure rate and maintenance costs. Attached Figure Description

[0017] The disclosure of this application will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this application. Wherein:

[0018] Figure 1 This is a schematic flowchart of the main steps of a blade aerodynamic efficiency evaluation method according to an embodiment of this application;

[0019] Figure 2 This is a schematic diagram of velocity composition and aerodynamic forces under leaf element rotation conditions according to an embodiment of this application;

[0020] Figure 3 This is a schematic diagram of the beam deformation state according to an embodiment of this application;

[0021] Figure 4 This is a schematic diagram of the main structure of a blade aerodynamic efficiency evaluation system according to an embodiment of this application;

[0022] Figure 5 This is a schematic diagram of the main structure of an electronic device according to an embodiment of this application.

[0023] Figure label:

[0024] 11: Memory; 12: Processor; 41: Blade deformation determination module; 42: Blade aerodynamic force determination module; 43: Aerodynamic data determination module; 44: Aerodynamic efficiency evaluation result determination module. Detailed Implementation

[0025] Some embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application.

[0026] In the description of this application, "module" and "processor" can include hardware, software, or a combination of both. A module can include hardware circuitry, various suitable sensors, communication ports, memory, and may also include software components, such as program code, or a combination of software and hardware. A processor can be a central processing unit, microprocessor, image processor, digital signal processor, or any other suitable processor. The processor has data and / or signal processing capabilities. The processor can be implemented in software, in hardware, or a combination of both. Computer-readable storage media includes any suitable medium capable of storing program code, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, etc. The term "A and / or B" means all possible combinations of A and B, such as only A, only B, or A and B. The terms "at least one A or B" or "at least one of A and B" have a similar meaning to "A and / or B" and can include only A, only B, or A and B. The singular terms "a" or "this" can also include plural forms.

[0027] As wind turbines continue to evolve towards larger and more efficient designs, the impeller diameter and aspect ratio of blades have undergone significant changes, resulting in a substantial increase in blade structural flexibility. However, while ultra-long flexible blades can improve wind energy capture efficiency in low-wind-speed regions, they also introduce serious aeroelastic coupling problems. Under complex conditions such as strong winds and turbulence, the interaction between aerodynamic loads and structural flexibility can easily induce nonlinear bending-torsional deformation in the blades, leading to the following key issues: aerodynamic performance degradation and efficiency loss; and increased structural fatigue and operational risks. Therefore, how to accurately quantify the aerodynamic efficiency of flexible blades has become an urgent problem to be solved.

[0028] To address this, the present application provides a blade aerodynamic efficiency evaluation method, comprising: determining the blade deformation under the final deformation state using a pre-constructed aeroelastic model and a blade tip loss coefficient database; determining the corrected blade aerodynamic force based on the blade deformation under the final deformation state; determining the aerodynamic data of the wind turbine based on the corrected blade aerodynamic force, the aerodynamic data including total thrust, total torque, and power; and determining the aerodynamic efficiency evaluation result of the blade based on the aerodynamic data of the wind turbine. This application analyzes the dynamic response characteristics of flexible blades under different wind speeds and turbulent conditions, thereby evaluating the aerodynamic efficiency and structural performance of the blades. This effectively optimizes the design of flexible blades, improves their aerodynamic efficiency and aeroelastic stability, and simultaneously reduces failure rates and maintenance costs.

[0029] See appendix Figure 1 , Figure 1 This is a schematic flowchart illustrating the main steps of a blade aerodynamic efficiency evaluation method according to an embodiment of this application. Figure 1As shown, the blade aerodynamic efficiency evaluation method in this application embodiment mainly includes the following steps S101 to S104.

[0030] Step S101: Using a pre-built aeroelastic model and a blade tip loss coefficient database, determine the blade deformation under the final deformation state.

[0031] Step S102: Based on the blade deformation under the final deformation state, determine the corrected blade aerodynamic force.

[0032] Step S103: Based on the corrected blade aerodynamic force, determine the aerodynamic data of the wind turbine, including total thrust, total torque and power.

[0033] Step S104: Based on the aerodynamic data of the wind turbine, determine the aerodynamic efficiency evaluation result of the blades.

[0034] Based on the methods described in steps S101 to S104 above, this application, based on a pre-constructed aeroelastic model and a blade tip loss coefficient database, comprehensively considers aerodynamic and structural coupling effects, and introduces Prandtl's blade tip loss factor and additional blade tip loss coefficients to determine the blade deformation and corrected blade aerodynamic forces under the final deformation state. Through the corrected blade aerodynamic forces, the total thrust, total torque, and output power of the wind turbine are determined. Finally, based on the total thrust, total torque, and output power of the wind turbine, the aerodynamic efficiency of the blade is quantitatively evaluated. Through collaborative analysis of the model and database, computational efficiency and accuracy are significantly improved. The aerodynamic efficiency of flexible blades under dynamic deformation can be comprehensively analyzed, effectively optimizing the structural design of flexible blades, improving their aerodynamic efficiency and aeroelastic stability, while reducing failure rates and maintenance costs.

[0035] The following provides further explanation of steps S101 to S104.

[0036] Regarding step S101, in one embodiment, the aeroelastic model includes an aerodynamic model and a structural model, wherein the aerodynamic model is constructed based on blade element momentum theory, and the structural model is constructed based on geometrically precise beam theory; the blade tip loss coefficient database includes multiple sets of deformation amplitudes and corresponding blade tip loss coefficients; the step of determining the blade deformation under the final deformation state using the pre-constructed aeroelastic model and blade tip loss coefficient database includes: determining the initial deformation of the blade based on the aeroelastic model; obtaining the corresponding blade tip loss coefficient from the blade tip loss coefficient database through linear interpolation based on the initial deformation; correcting the blade tip loss factor in the aerodynamic model based on the blade tip loss coefficient corresponding to the initial deformation, iteratively updating the aerodynamic force and deformation, and determining the blade deformation under the final deformation state.

[0037] Specifically, before implementing the method of this application, it is necessary to construct an aerodynamic model based on blade element momentum theory, a structural model based on geometrically accurate beam theory, and a database of blade tip loss coefficients.

[0038] Based on the blade element momentum theory, an aerodynamic model is constructed. The following assumptions are made first: the wind turbine is composed of an infinite number of blades, and the wind turbine is simplified to a planar blade disk; the incoming wind speed is uniform and steady, that is, the compressibility of air is not considered; the radial blade elements are assumed to be independent of each other, with no interaction between them, and the radial flow of particles in the flow field is ignored; the influence of the induced velocity in the wake region caused by the rotation of the wind turbine is ignored.

[0039] When airflow passes over the blades and the rotor's plane of rotation, its axial and tangential velocities change. Axial induction factors 'a' and tangential induction factors 'b' are introduced to reflect the velocity reduction as the airflow passes over the rotor. The velocity composition relationship and aerodynamic forces under blade rotation conditions are as follows: Figure 2 As shown.

[0040] The velocity composition relationship can be expressed as:

[0041]

[0042] In the formula, V is the free flow velocity; v is the inflow angle; Ω is the rotor speed; a is the axial induction factor; b is the tangential induction factor; and r is the radius at the blade position where the leaf element is located.

[0043] The relationship between the inflow angle φ, the angle of attack α, and the pitch angle β is as follows:

[0044] α=φ-β

[0045] Leaf element lift dF l The resistance dF of leaf element d The expression is:

[0046]

[0047] In the formula, ρ is the air density; W is the incoming confluence velocity; C is the chord length; C L C is the airfoil lift coefficient; D This represents the airfoil drag coefficient.

[0048] Decomposing the lift and drag forces acting on the blade element into the plane of rotation of the wind turbine and in directions perpendicular to the plane of rotation, we obtain the normal force F acting on the blade element. n and tangential force F t :

[0049]

[0050] In the formula, C n C is the normal force coefficient. tThe tangential force coefficient is expressed as:

[0051] C n =C L cosφ+C D sinφ

[0052] C t =C L sinφ-C D cosφ

[0053] The thrust and torque of the infinitesimal ring located at a distance r from the center of the wind turbine can be calculated using the following formula:

[0054]

[0055]

[0056] In the formula, B is the number of blades; dT 叶素 The thrust acting on the leaf element; dM 叶素 The torque experienced by the leaf element.

[0057] According to the momentum theorem, the thrust and torque acting on a small ring of width dr at radius r of the wind turbine are:

[0058] dT 动量 =4πρV 2 (1-a)ardr

[0059] dM 动量 =4πρVΩ(1-a)br 3 dr

[0060] In actual wind turbine operation, due to the limited number of turbine blades, tip vortices can detach from the blade disk. A portion of the inflow flows around the lower surface of the blade tip to the upper surface, resulting in secondary flow near the blade tip. The presence of these detached tip vortices drastically reduces the aerodynamic performance near the blade tip. Traditional blade element momentum theory (BEM), based on the assumption of infinite blades, cannot accurately characterize the energy dissipation and inflow distortion caused by tip vortices, leading to a reduction in turbine output power. To compensate for the calculation errors caused by tip vortex detachment, a tip loss factor F is proposed to compensate for the blade element aerodynamic forces. prandtl Represented as:

[0061]

[0062] Then the tip loss factor F is introduced. prandtl The momentum theorem can be rewritten as:

[0063] dT 动量 =4πρV 2 (1-a)arFprandtl dr

[0064] dM 动量 =4πρVΩ(1-a)br 3 F prandtl dr

[0065] Using dT 叶素 =dT 动量 ,dM 叶素 =dM 动量 The axial induction factor and tangential induction factor are obtained as follows:

[0066]

[0067] The iterative calculation process for calculating aerodynamic loads based on aerodynamic models can be summarized as follows:

[0068] Initialize the induction factors: Assume that the axial induction factor a = tangential induction factor b = 0, as the initial value for iterative calculation. Calculate the inflow angle φ based on the velocity composition relation. Obtain the angle of attack α from the inflow angle φ and the pitch angle β.

[0069] Based on the angle of attack α, the lift coefficient and drag coefficient corresponding to the angle of attack are obtained from the pre-stored airfoil data table. Then, based on the lift coefficient, drag coefficient and inflow angle, the normal force coefficient and tangential force system are determined.

[0070] Substituting the normal force coefficient, tangential force coefficient, and inflow angle into the above formulas for solving a and b yields the axial induction factor a and the tangential induction factor b. This completes one iteration. Repeat this iteration until both a and b converge. Then, substitute the converged values ​​of a and b back into the formulas for the thrust and torque of the infinitesimal element to obtain the aerodynamic forces on the blade element. Integrating the aerodynamic forces on the blade element along the blade span gives the aerodynamic loads on the blade and the rotor.

[0071] When constructing a structural model based on geometrically accurate beam theory, the blades are simplified into beam elements, and the beam deformation state is as follows: Figure 3 As shown. The nonlinear motion control equations of the geometrically precise beam theory are as follows:

[0072]

[0073] In the formula, h and g are the linear momentum and angular momentum in the inertial coordinate system, respectively; F and M are the cross-sectional force and moment of the beam, respectively; u is the linear displacement of a point on the reference line; x0 is the position vector of the point along the beam reference line; f and m are the distributed force and moment applied to the beam structure. The symbol F' represents the derivative of the relative axial displacement. Represents the derivative with respect to time. The tilde operator defines a skew-symmetric tensor corresponding to a given vector.

[0074] The constitutive equations correlate velocity with momentum, and one-dimensional strain measurements with cross-sectional results.

[0075]

[0076]

[0077] Where M is the 6×6 cross-sectional mass matrix, C is the 6×6 cross-sectional stiffness matrix; ε is the one-dimensional strain; k is the curvature; ω is the angular velocity vector defined by the rotation tensor R, where ω=axial(RR) T Vector a is associated with a second-order tensor A, and its components are defined as follows:

[0078]

[0079] One-dimensional strain ε and curvature k are defined as follows:

[0080]

[0081] Where, K = axial[(RR0)'(RR0)] T K is the cross-sectional curvature vector decomposed on the inertial basis; x'0 is the derivative of the initial position vector with respect to the s-axis; u' is the derivative of the displacement vector with respect to the s-axis; R is the current rotation tensor, R0 is the initial rotation tensor; l1 is the unit vector along the x1 direction in the inertial basis. The above equations together form the mathematical description of the geometrically accurate elastic beam problem.

[0082] The nonlinear control equations of the beam are solved using the Newton-Raphson method, and the incremental equations are discretized using the Legendre spectral finite element method. The linearized form of the nonlinear control equations is shown below:

[0083]

[0084] in, The unit mass matrix; It is a rotation matrix; Here is the stiffness matrix; To represent the generalized elemental acceleration; For speed in a general sense, This is the generalized increment of the node displacement array; This represents an externally applied load; It is represented as a unit force.

[0085] The time integral is calculated using a generalized α-time integrator:

[0086] |ΔU (i)T ( t+Δt R- t+Δt F(i-1) )|≤|ε E [ΔU (1)T ( t+Δt R- t F)]|

[0087] Where ΔU is the increment of the displacement vector, R is the externally applied nodal load vector, F is the nodal force vector corresponding to the internal element stress, and ε E The superscript on the left of the variable represents the time value, indicating that it is in dynamic analysis, and the superscript on the right represents the number of iterations.

[0088] The three-dimensional rotation of a geometrically accurate beam can be expressed by the Wiener-Milenkovic parameters, represented by the following equation:

[0089]

[0090] in, Let be the rotation angle, and n be the unit vector of the rotation axis.

[0091] The wind turbine blade is modeled as a beam element, with corresponding structural parameters such as geometric parameters, material properties, and mass distribution parameters input. The nodal degrees of freedom are numerically implemented using the Legendre spectral finite element method. The wind turbine blade is modeled using a single element through the trapezoidal quadrature method. The three-dimensional rotation of the blade is represented by Wiener-Milenkovic parameters, yielding the linear and angular displacements of each node. The nonlinear motion control equations are solved using the Newton-Raphson method. After linearization, a generalized α-time integrator is used to determine the convergence of the equations.

[0092] When constructing the blade tip loss coefficient database, aerodynamic data of multiple preset deformation amplitudes of the blade are obtained through CFD numerical simulation. The multiple preset deformation amplitudes η can be: η1 = 0%, η2 = 5%, η3 = 10%, η4 = 15%, and η5 = 20%. First, the blade geometric model is generated for each of the multiple preset deformation amplitudes of the blade, and the CFD calculation mesh is drawn.

[0093] Then, CFD numerical simulation was performed on the above mesh model to calculate the blade aerodynamic forces. The aerodynamic forces of the deformed blade were compared with those of the undeformed blade to obtain the additional tip loss coefficient, which was defined as F. extra And it is associated with the preset deformation range.

[0094] The blade deformation amplitude may not be equal to the data used in the simulation. Therefore, a linear interpolation formula is used to calculate the tip loss coefficient F under any deformation amplitude based on the data obtained from the CFD simulation. extraInterpolation methods can generate smooth curves between data points, ensuring the continuity and accuracy of the tip loss coefficient throughout the deformation range, thus enabling better simulation of the aerodynamic performance of actual blades under different deformations.

[0095] For a known point (ω) i F extra(i) ), (ω i+1 F extra(i+1) ), for the blade tip deformation amplitude ω in the interval (ω i ω i+1 When the interval is within ), the interpolation formula is:

[0096]

[0097] Where ω is the tip deflection in the interval (ω i ω i+1 Arbitrary deformation range within )

[0098] Based on the obtained arbitrary deformation amplitude and the corresponding tip loss coefficient, a tip loss coefficient database is obtained.

[0099] In one embodiment, determining the initial deformation of the blade based on the aeroelastic model includes: determining the initial aerodynamic force of the blade using the aerodynamic model based on the geometric parameters of the undeformed blade; and determining the initial deformation of the blade using the structural model based on the initial aerodynamic force of the blade.

[0100] Specifically, based on the structural parameters of the undeformed blade, the initial aerodynamic force F1 of the undeformed blade is calculated through an aerodynamic model and input into the structural model to obtain the initial deformation w1 of the blade under the initial aerodynamic force F1.

[0101] Then, based on the initial deformation w1 of the blade, the tip loss coefficient F corresponding to the initial deformation w1 of the blade is obtained from the tip loss coefficient database using the above interpolation formula. extra (w1).

[0102] In one implementation, the step of correcting the tip loss factor in the aerodynamic model based on the tip loss coefficient corresponding to the initial deformation, iteratively updating the aerodynamic force and deformation, and determining the blade deformation under the final deformation state includes: correcting the tip loss factor in the aerodynamic model based on the tip loss coefficient and Prandtl tip loss factor corresponding to the initial deformation; updating the aerodynamic force based on the corrected aerodynamic model to obtain the updated aerodynamic force; determining whether the relative error between the aerodynamic force before the update and the updated aerodynamic force is less than a preset threshold; if so, inputting the updated aerodynamic force into the structural model to determine the blade deformation under the final deformation state; otherwise, inputting the updated aerodynamic force into the structural model, calculating the new deformation, and repeatedly updating the aerodynamic force until the relative error between the aerodynamic force before the update and the updated aerodynamic force is less than the preset threshold.

[0103] Specifically, after the blade deforms, the aerodynamic force F1 acting on the blade will change, requiring a reassessment of the aerodynamic force. Based on the tip loss coefficient and Prandtl tip loss factor corresponding to the initial deformation, the tip loss factor in the aerodynamic model is corrected. The calculation formula is as follows:

[0104] F(r)=F extra *F prandtl

[0105] In the formula, F(r) is the corrected tip loss factor, F extra F is the tip loss coefficient corresponding to the initial deformation. prandtl This is the Prandtl leaf tip loss factor.

[0106] Based on the corrected aerodynamic model, the aerodynamic force is updated to obtain the updated aerodynamic force. It is then determined whether the relative error between the aerodynamic force before and after the update is less than a preset threshold. If so, the updated aerodynamic force is input into the structural model to determine the blade deformation corresponding to the updated aerodynamic force, and the blade deformation under the final deformation state is obtained.

[0107] If the relative error between the aerodynamic forces before and after the update is greater than or equal to a preset threshold, the updated aerodynamic forces are input into the structural model to calculate the new blade deformation, and the aerodynamic forces are updated repeatedly until the relative error between the aerodynamic forces before and after the update is less than the preset threshold.

[0108] Regarding step S102, in one embodiment, determining the corrected blade aerodynamic force based on the blade deformation under the final deformation state includes: obtaining the blade tip loss coefficient corresponding to the blade deformation under the final deformation state from the blade tip loss coefficient database through linear interpolation based on the blade deformation under the final deformation state; determining the corrected blade aerodynamic force based on the blade tip loss coefficient corresponding to the blade deformation under the final deformation state, considering the change in projected area caused by deformation, wherein the corrected blade aerodynamic force includes the thrust and torque at each blade element position within the rotor plane.

[0109] Specifically, after obtaining the blade deformation under the final deformation state, the tip loss coefficient F under the final deformation state is determined by using an interpolation formula and combining it with a tip loss coefficient database. extra And based on the tip loss coefficient F under the final deformation state. extra The aerodynamic forces were then corrected to obtain the thrust and torque based on the tip loss coefficient.

[0110] The steps for correcting aerodynamic forces include:

[0111] Calculate the new values ​​of axial induction factor a and tangential induction factor b:

[0112]

[0113] In the formula, F(r) = F extra *F prandtl It is the product of the tip loss coefficient and Prandtl tip loss factor.

[0114] Compare the new values ​​of axial induction factor a and tangential induction factor b with the values ​​of the previous iteration. If the error is less than the set error value, the new values ​​can be taken; otherwise, the new values ​​of axial induction factor a and tangential induction factor b are used as the values ​​of the previous iteration, the new values ​​of axial induction factor a and tangential induction factor b are recalculated, and the iteration continues.

[0115] Based on the determined axial induction factor a and tangential induction factor b, the inflow angle φ and angle of attack α are solved to obtain the lift coefficient and drag coefficient. Considering the influence of blade deformation, the airfoil section at the blade tip deviates from the rotor plane, resulting in a change in the projected area during calculation. The angle between the tangent of the blade at a distance r from the blade root after deformation and the original blade is set as γ. The aerodynamic force caused by the incoming confluence velocity W acting on the blade element of length dr after deformation can be decomposed into a normal force dF. n and tangential force dF t Then the expressions for the normal force and tangential force of the deformed section are:

[0116]

[0117] At this point, the thrust acting on the dr ring at each blade element position on the wind turbine plane can be expressed as:

[0118]

[0119] The torque acting on the dr ring at each blade element position in the rotor plane is:

[0120]

[0121] Regarding step S103, in one embodiment, determining the aerodynamic data of the wind turbine based on the corrected blade aerodynamic forces includes: integrating the thrust and torque at each blade element position in the rotor plane along the blade span to obtain the total thrust and total torque of the wind turbine; and determining the power of the wind turbine based on the total torque and rotor speed.

[0122] Specifically, the thrust and torque at each blade element position within the rotor plane are integrated along the blade span to obtain the total thrust and total torque of the wind turbine. The formula for calculating the total thrust of the wind turbine is as follows:

[0123]

[0124] The formula for calculating the total torque of a wind turbine is:

[0125]

[0126] Finally, based on the total torque and rotor speed of the wind turbine, the power of the wind turbine is determined. The formula for calculating the power of the wind turbine is as follows:

[0127] P 风力机 =M 风力机 ω

[0128] In the formula, ω is the wind turbine rotation speed.

[0129] Regarding step S104, in one embodiment, determining the aerodynamic efficiency evaluation result of the blades based on the aerodynamic data of the wind turbine includes: determining the wind energy utilization coefficient based on the power of the wind turbine; determining the thrust coefficient based on the total thrust of the wind turbine; determining the torque coefficient based on the total torque of the wind turbine; and using the wind energy utilization coefficient, the thrust coefficient, and the torque coefficient as the aerodynamic efficiency evaluation result.

[0130] Specifically, the wind energy utilization coefficient C p The power of the wind turbine is determined by the ratio of its power to the free-flow wind power corresponding to its swept area. The calculation formula is as follows:

[0131]

[0132] In the formula, ρ is the air density; A is the swept area of ​​the wind turbine, A=πR 2 V represents the incoming air velocity.

[0133] Based on the total thrust of the wind turbine, the thrust coefficient C is determined using the following formula. T :

[0134]

[0135] Based on the total torque of the wind turbine, the torque coefficient C is determined using the following formula. M :

[0136]

[0137] Finally, the aerodynamic efficiency evaluation results of the wind turbine were obtained: wind energy utilization coefficient, thrust coefficient, and torque coefficient.

[0138] It should be noted that although the steps in the above embodiments are described in a specific order, those skilled in the art will understand that in order to achieve the effect of this application, different steps do not necessarily have to be executed in such an order. They can be executed simultaneously (in parallel) or in other orders. These adjusted solutions are equivalent to the technical solutions described in this application and therefore will also fall within the protection scope of this application.

[0139] Those skilled in the art will understand that all or part of the processes in the method of the above-described embodiment can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer-readable storage medium can include any entity or device capable of carrying the computer program code, a medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory, a random access memory, an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0140] Another aspect of this application provides a blade aerodynamic efficiency evaluation system.

[0141] See appendix Figure 4 , Figure 4 This is a schematic diagram of the main structure of a blade aerodynamic efficiency evaluation system according to an embodiment of this application. Figure 4As shown, the blade aerodynamic efficiency evaluation system of this application includes: a blade deformation determination module 41, a blade aerodynamic force determination module 42, an aerodynamic data determination module 43, and an aerodynamic efficiency evaluation result determination module 44. In some embodiments, one or more of the blade deformation determination module 41, blade aerodynamic force determination module 42, aerodynamic data determination module 43, and aerodynamic efficiency evaluation result determination module 44 can be combined into a single module.

[0142] In some embodiments, the blade deformation determination module 41 can be configured to determine the blade deformation under the final deformation state using a pre-built aeroelastic model and a blade tip loss coefficient database; the blade aerodynamic force determination module 42 can be configured to determine the corrected blade aerodynamic force based on the blade deformation under the final deformation state; the aerodynamic data determination module 43 can be configured to determine the aerodynamic data of the wind turbine based on the corrected blade aerodynamic force, wherein the aerodynamic data includes total thrust, total torque, and power; and the aerodynamic efficiency evaluation result determination module 44 can be configured to determine the aerodynamic efficiency evaluation result of the blade based on the aerodynamic data of the wind turbine. In one embodiment, a description of the specific functions can be found in steps S101 to S104.

[0143] The aforementioned blade aerodynamic efficiency evaluation system is used for execution Figure 1 The blade aerodynamic efficiency evaluation method embodiments shown are similar in technical principle, technical problem solved and technical effect produced. Those skilled in the art can clearly understand that, for the sake of convenience and brevity, the specific working process and related instructions of the blade aerodynamic efficiency evaluation system can be referred to the content described in the embodiments of the blade aerodynamic efficiency evaluation method, which will not be repeated here.

[0144] Another aspect of this application provides an electronic device.

[0145] In one embodiment of an electronic device according to this application, the electronic device may include at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program that, when executed by the at least one processor, implements the methods described in any of the above embodiments. See Appendix Figure 5 , Figure 5 The image exemplarily illustrates a communication connection between memory 11 and processor 12 via a bus. In some embodiments of this application, the electronic device may also include at least one sensor for sensing information. The sensor is communicatively connected to any type of processor mentioned in this application.

[0146] Another aspect of this application provides a computer-readable storage medium.

[0147] In one embodiment of a computer-readable storage medium according to this application, the computer-readable storage medium can be configured to store a program that performs the blade aerodynamic efficiency evaluation method of the above-described method embodiments. This program can be loaded and run by a processor to implement the blade aerodynamic efficiency evaluation method. For ease of explanation, only the parts related to the embodiments of this application are shown; for specific technical details not disclosed, please refer to the method section of the embodiments of this application. The computer-readable storage medium can be a storage device comprising various electronic devices. Optionally, in the embodiments of this application, the computer-readable storage medium is a non-transitory computer-readable storage medium.

[0148] The technical solution of this application has been described above with reference to one embodiment shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A method for evaluating the aerodynamic efficiency of blades, characterized in that, The method includes: Using a pre-built aeroelastic model and a blade tip loss coefficient database, the blade deformation under the final deformation state is determined; the blade tip loss coefficient database includes multiple sets of deformation amplitudes and corresponding blade tip loss coefficients. Based on the blade deformation under the final deformation state, the corrected blade aerodynamic force is determined. Based on the corrected blade aerodynamic forces, the aerodynamic data of the wind turbine are determined, including total thrust, total torque, and power. Based on the aerodynamic data of the wind turbine, the aerodynamic efficiency evaluation result of the blades is determined; The step of determining the corrected blade aerodynamic force based on the blade deformation under the final deformation state includes: obtaining the blade tip loss coefficient corresponding to the blade deformation under the final deformation state from the blade tip loss coefficient database through linear interpolation based on the blade deformation under the final deformation state; and determining the corrected blade aerodynamic force based on the blade tip loss coefficient corresponding to the blade deformation under the final deformation state, considering the change in projected area caused by deformation. The corrected blade aerodynamic force includes the thrust and torque at each blade element position within the rotor plane.

2. The method for evaluating blade aerodynamic efficiency according to claim 1, characterized in that, The aeroelastic model includes an aerodynamic model and a structural model, wherein the aerodynamic model is constructed based on the leaf element momentum theory and the structural model is constructed based on the geometrically accurate beam theory; The process of determining the blade deformation under the final deformation state using a pre-built aeroelastic model and a blade tip loss coefficient database includes: Based on the aforementioned aeroelastic model, the initial deformation of the blade is determined; Based on the initial deformation, the corresponding tip loss coefficient is obtained from the tip loss coefficient database by linear interpolation; Based on the tip loss coefficient corresponding to the initial deformation, the tip loss factor in the aerodynamic model is corrected, the aerodynamic force and deformation are iteratively updated, and the blade deformation under the final deformation state is determined.

3. The method for evaluating blade aerodynamic efficiency according to claim 2, characterized in that, The determination of the initial deformation of the blade based on the aeroelastic model includes: Based on the geometric parameters of the undeformed blade, the initial aerodynamic force of the blade is determined using the aforementioned aerodynamic model. Based on the initial aerodynamic forces of the blade, the initial deformation of the blade is determined using the structural model.

4. The method for evaluating blade aerodynamic efficiency according to claim 2, characterized in that, The step of correcting the tip loss factor in the aerodynamic model based on the tip loss coefficient corresponding to the initial deformation, iteratively updating the aerodynamic forces and deformation, and determining the blade deformation under the final deformation state includes: Based on the tip loss coefficient and Prandtl tip loss factor corresponding to the initial deformation, the tip loss factor in the aerodynamic model is corrected. Based on the corrected aerodynamic model, the aerodynamic forces are updated to obtain the updated aerodynamic forces; Determine whether the relative error between the aerodynamic force before and after the update is less than a preset threshold. If so, input the updated aerodynamic force into the structural model to determine the blade deformation under the final deformation state. Otherwise, the updated aerodynamic force is input into the structural model, the new deformation is calculated, and the aerodynamic force is updated repeatedly until the relative error between the aerodynamic force before and after the update is less than a preset threshold.

5. The method for evaluating blade aerodynamic efficiency according to claim 1, characterized in that, The process of determining the aerodynamic data of the wind turbine based on the corrected blade aerodynamic forces includes: The thrust and torque at each blade element position within the rotor plane are integrated along the blade span to obtain the total thrust and total torque of the wind turbine. The power of the wind turbine is determined based on its total torque and rotor speed.

6. The method for evaluating the aerodynamic efficiency of blades according to claim 1, characterized in that, The determination of the aerodynamic efficiency evaluation result of the blades based on the aerodynamic data of the wind turbine includes: Based on the power of the wind turbine, the wind energy utilization coefficient is determined; The thrust coefficient is determined based on the total thrust of the wind turbine. The torque coefficient is determined based on the total torque of the wind turbine. The wind energy utilization coefficient, the thrust coefficient, and the torque coefficient are used as the aerodynamic efficiency evaluation results.

7. A blade aerodynamic efficiency evaluation system, characterized in that, The system includes: The blade deformation determination module is used to determine the blade deformation under the final deformation state using a pre-built aeroelastic model and a blade tip loss coefficient database; the blade tip loss coefficient database includes multiple sets of deformation amplitudes and corresponding blade tip loss coefficients. The blade aerodynamic force determination module is used to determine the corrected blade aerodynamic force based on the blade deformation under the final deformation state. The aerodynamic data determination module is used to determine the aerodynamic data of the wind turbine based on the corrected blade aerodynamic forces, wherein the aerodynamic data includes total thrust, total torque and power; The aerodynamic efficiency evaluation result determination module is used to determine the aerodynamic efficiency evaluation result of the blades based on the aerodynamic data of the wind turbine. The step of determining the corrected blade aerodynamic force based on the blade deformation under the final deformation state includes: obtaining the blade tip loss coefficient corresponding to the blade deformation under the final deformation state from the blade tip loss coefficient database through linear interpolation based on the blade deformation under the final deformation state; and determining the corrected blade aerodynamic force based on the blade tip loss coefficient corresponding to the blade deformation under the final deformation state, considering the change in projected area caused by deformation. The corrected blade aerodynamic force includes the thrust and torque at each blade element position within the rotor plane.

8. An electronic device comprising at least one processor and at least one memory, said memory being adapted to store a plurality of program codes, characterized in that, The program code is adapted to be loaded and run by the processor to perform the blade aerodynamic efficiency evaluation method according to any one of claims 1 to 6.

9. A computer-readable storage medium storing a plurality of program codes, characterized in that, The program code is adapted to be loaded and run by a processor to perform the blade aerodynamic efficiency evaluation method according to any one of claims 1 to 6.

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