Fan blade extension optimization method and system based on finite element analysis

Abstract

The invention provides a fan blade extension optimization method and system based on finite element analysis, and relates to the technical field of wind power design, and the method comprises the steps: obtaining the overall structure and blade appearance of a wind wheel, and obtaining the parameters of the wind wheel; the blade tip speed ratio is calculated by analyzing the influence of wind wheel parameters on the blade appearance, and blade chord length and airfoil parameters are obtained to construct a three-dimensional model of the blade; according to the three-dimensional model of the blade, blade aerodynamic shape design and aerodynamic load analysis are carried out to obtain a blade shape and load analysis result; and according to the blade appearance and the load analysis result, constructing a blade finite element model. According to the method, the extension optimization design of the fan blade is realized by means of collecting wind regime data, accurately calculating blade parameters, constructing a three-dimensional model, carrying out pneumatic analysis and finite element analysis and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power design, and particularly to a method and system for optimizing the extension of a wind turbine blade based on finite element analysis. Background Art

[0002] In wind power generation technology, wind turbine blades play a crucial role in a wind power generation system. They are the core components that capture wind energy and convert it into rotational mechanical energy, directly affecting the power generation efficiency and performance of the wind turbine. Therefore, how to optimize the design of wind turbine blades to improve their wind energy capture efficiency and conversion efficiency has become an important topic in wind energy technology research and development.

[0003] However, traditional wind turbine blade design methods sometimes rely on experience and theoretical calculations, making it difficult to comprehensively consider various complex factors in the actual operating environment. For example, natural factors such as changes in wind speed, frequent changes in wind direction, and atmospheric turbulence will have a significant impact on the aerodynamic performance and structural strength of the blades. The neglect or simplification of these factors may lead to problems such as poor performance and insufficient structural strength of the designed blades in actual operation, thereby affecting the stability and economy of the entire wind power generation system. Specifically, if the blade design fails to fully consider the complexity of the actual wind conditions, it may result in the inability to effectively capture wind energy under certain wind speed or wind direction conditions. These problems will not only reduce the power generation efficiency of the wind turbine but also increase maintenance costs and safety hazards. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for optimizing the extension of a wind turbine blade based on finite element analysis, which realizes the optimized design of the extension of the wind turbine blade by collecting wind condition data, accurately calculating blade parameters, constructing a three-dimensional model, performing aerodynamic analysis and finite element analysis, etc.

[0005] To solve the above technical problems, the technical solution of the present invention is as follows:

[0006] In the first aspect, a method for optimizing the extension of a wind turbine blade based on finite element analysis, the method includes:

[0007] Obtain the overall structure of the wind turbine rotor and the blade shape, and obtain the wind turbine rotor parameters;

[0008] By analyzing the influence of the wind turbine rotor parameters on the blade shape, calculate the tip speed ratio, and obtain the blade chord length and airfoil parameters to construct a three-dimensional model of the blade;

[0009] According to the three-dimensional model of the blade, perform aerodynamic shape design and aerodynamic load analysis of the blade to obtain the blade shape and load analysis results;

[0010] According to the blade shape and load analysis results, construct a finite element model of the blade;

[0011] According to the blade finite element model, perform finite element simulation analysis on the blade under different working conditions to obtain the finite element analysis results;

[0012] Based on the finite element analysis results, conduct an extended optimization design on the blade to obtain the extended optimization results of the wind turbine blade.

[0013] Furthermore, obtain the overall structure of the wind wheel and the blade profile, and obtain the wind wheel parameters, including:

[0014] Collect wind condition data and obtain wind condition parameters to determine the cut-in wind speed, rated wind speed, and cut-out wind speed of the wind turbine;

[0015] According to the wind speed, design the overall structure of the wind wheel to determine the diameter, height, and rated rotational speed parameters of the wind wheel. The overall structure of the wind wheel includes blades, winglets, rotating arms, winglet yaw mechanisms, and rotating arm deployment and telescoping mechanisms.

[0016] Furthermore, by analyzing the influence of the wind wheel parameters on the blade profile, calculate the tip speed ratio, obtain the blade chord length and airfoil parameters, and construct the three-dimensional model of the blade, including:

[0017] According to the wind wheel parameters and wind condition parameters, through calculate the lift on each blade element, and through calculate the drag on each blade element, and combine the lift on each blade element and the drag on each blade element to obtain the aerodynamic force on each blade element. Among them, F L is the lift, F D is the drag, ρ is the air density, c(r) is the chord length of the blade element, V is the oncoming wind speed, r is the distance from the blade element to the center of the wind wheel, ω is the angular velocity of the wind wheel, C l (α(r)) is the lift coefficient, Y a is the angle between the axis of the wheel rotation and the wind direction, dr is the width of a small segment on the blade, Cl and ×C d (α(r)) are the lift coefficient and drag coefficient respectively, T i is the turbulence intensity coefficient;

[0018] According to the wind wheel parameters and wind condition parameters, through obtain the velocity change of the air flow after passing through the blade. Among them, v a is the axial induction velocity, V is the oncoming wind speed, C T is the thrust coefficient;

[0019] According to the aerodynamic force on each blade element and the velocity change of the air flow after passing through the blade, through calculate the tip speed ratio, blade chord length, and airfoil parameters. Among them, λ is the tip speed ratio, ω is the angular velocity of the wind wheel, R is the radius of the wind wheel, and V1 is the upstream wind speed;

[0020] Based on the tip speed ratio, blade chord length, and airfoil parameters, a three-dimensional model of the blade is constructed.

[0021] Furthermore, based on the three-dimensional model of the blade, aerodynamic shape design and aerodynamic load analysis of the blade are carried out to obtain the blade shape and load analysis results, including:

[0022] Based on the three-dimensional model of the blade, the aerodynamic shape of the blade is designed;

[0023] Based on the aerodynamic shape of the blade, the aerodynamic load of the blade in the wind field is simulated and analyzed by CFD to obtain the aerodynamic load results, which include the power, power coefficient, torque, and thrust received by the blade.

[0024] Furthermore, based on the blade shape and load analysis results, a finite element model of the blade is constructed, including:

[0025] Based on the blade shape and load analysis results, including the geometric shape, dimensions, material properties of the blade, and the aerodynamic load under different wind speeds and wind directions;

[0026] Based on the blade shape and load analysis results, ANSYS finite element analysis software is selected to establish the geometric model of the blade;

[0027] Based on the geometric model of the blade, the material properties and boundary conditions of the blade model are determined.

[0028] The geometric model of the blade is meshed, and finite element analysis is carried out according to the material properties and boundary conditions of the blade model to simulate the stress situation of the blade in the actual wind field to obtain stress distribution and deformation data;

[0029] Based on the stress distribution and deformation data, a finite element model of the blade is constructed.

[0030] Furthermore, based on the finite element model of the blade, finite element simulation analysis of the blade under different working conditions is carried out to obtain finite element analysis results, including:

[0031] Determine the objectives and working conditions of the simulation analysis;

[0032] According to the objectives and working conditions of the simulation analysis, set the boundary conditions and loads for the finite element model simulation analysis of the blade;

[0033] According to the boundary conditions and loads of the simulation analysis, carry out finite element simulation analysis of the blade under different working conditions to obtain stress distribution, maximum stress value, deformation situation, and natural frequency to evaluate the structural strength and stiffness of the blade;

[0034] Carry out local buckling simulation analysis on the blade to evaluate the buckling safety factor;

[0035] According to the structural strength, stiffness and buckling safety factor of the blade, the finite element analysis results are obtained.

[0036] Furthermore, based on the finite element analysis results, an extended optimization design of the blade is carried out to obtain the extended optimization results of the wind turbine blade, including:

[0037] According to the finite element analysis results, the blade length is adjusted and the airfoil is changed to achieve blade extension;

[0038] According to the load analysis results, the geometric shape and material distribution of the extended part of the blade are adjusted to minimize stress concentration and deformation, so as to obtain the extended optimization results of the wind turbine blade.

[0039] In a second aspect, an extended optimization system for a wind turbine blade based on finite element analysis includes:

[0040] An acquisition module for acquiring the overall structure of the wind wheel and the blade profile, and acquiring wind wheel parameters;

[0041] An analysis module for calculating the tip speed ratio by analyzing the influence of wind wheel parameters on the blade profile, obtaining the chord length and airfoil parameters of the blade to construct a three-dimensional model of the blade; according to the three-dimensional model of the blade, performing aerodynamic shape design and aerodynamic load analysis of the blade to obtain the blade profile and load analysis results;

[0042] An optimization module for constructing a finite element model of the blade according to the blade profile and load analysis results; performing finite element simulation analysis on the blade under different working conditions according to the finite element model of the blade to obtain finite element analysis results; based on the finite element analysis results, performing extended optimization design on the blade to obtain the extended optimization results of the wind turbine blade.

[0043] In a third aspect, a computing device includes:

[0044] One or more processors;

[0045] A storage device for storing one or more programs, which when executed by the one or more processors cause the one or more processors to implement the method.

[0046] In a fourth aspect, a computer-readable storage medium stores a program which, when executed by a processor, implements the method.

[0047] The above solutions of the present invention at least include the following beneficial effects:

[0048] By collecting wind condition data and obtaining wind condition parameters, it is possible to ensure that the wind turbine design better conforms to the actual operating environment and improve the utilization rate of wind energy; designing the overall structure of the wind turbine according to the wind speed can ensure the structural strength and operating efficiency of the wind turbine while reducing unnecessary material costs. Accurately calculating the tip speed ratio, blade chord length, and airfoil parameters helps to construct a more accurate three-dimensional model of the blade, providing an accurate basis for subsequent aerodynamic analysis and optimization design; by considering multiple factors such as lift, drag, and airflow velocity changes, it is possible to ensure that the blade design achieves optimal aerodynamic performance. Conducting aerodynamic shape design based on the three-dimensional model can ensure that the shape and size of the blade achieve the best aerodynamic performance and improve the power generation efficiency of the wind turbine; by using CFD simulation to analyze aerodynamic loads, it is possible to accurately predict the force conditions of the blade during actual operation. Combining the geometric shape, size, material properties, and aerodynamic loads of the blade to construct a finite element model can ensure the authenticity and accuracy of the model; by using finite element analysis software to mesh and analyze the model, it is possible to simulate the complex force conditions of the blade in the actual wind field and provide data support for evaluating the structural strength and stiffness of the blade. By determining the objectives and working conditions of the simulation analysis and setting reasonable boundary conditions and loads, it is possible to ensure the pertinence and effectiveness of the simulation analysis; obtaining data such as stress distribution, maximum stress value, deformation conditions, and natural frequency helps to comprehensively evaluate the structural performance and safety of the blade; conducting local buckling simulation analysis on the blade can further ensure the stability and safety of the blade under extreme working conditions. Adjusting the blade length and airfoil according to the finite element analysis results can achieve the extended design of the blade, thereby improving the wind capture ability and power generation efficiency of the wind turbine; by adjusting the geometric shape and material distribution of the extended part of the blade, it is possible to minimize stress concentration and deformation and ensure the structural safety and durability of the blade after extension. Brief Description of the Drawings

[0049] Figure 1 is a schematic flow chart of a method for optimizing the extension of a wind turbine blade based on finite element analysis provided by an embodiment of the present invention.

[0050] Figure 2 is a schematic diagram of a system for optimizing the extension of a wind turbine blade based on finite element analysis provided by an embodiment of the present invention. Detailed Embodiments

[0051] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art.

[0052] As Figure 1As shown in the figure, an embodiment of the present invention proposes a method for optimizing the extension of a wind turbine blade based on finite element analysis. The method includes the following steps:

[0053] Step 11: Obtain the overall structure of the wind turbine and the blade profile, and obtain the wind turbine parameters;

[0054] Step 12: By analyzing the influence of the wind turbine parameters on the blade profile, calculate the tip speed ratio, obtain the chord length and airfoil parameters of the blade, and construct a three-dimensional model of the blade;

[0055] Step 13: According to the three-dimensional model of the blade, perform aerodynamic shape design and aerodynamic load analysis of the blade to obtain the blade profile and load analysis results;

[0056] Step 14: According to the blade profile and load analysis results, construct a finite element model of the blade;

[0057] Step 15: According to the finite element model of the blade, perform finite element simulation analysis on the blade under different working conditions to obtain the finite element analysis results;

[0058] Step 16: Based on the finite element analysis results, perform extension optimization design on the blade to obtain the optimization result of the wind turbine blade extension.

[0059] In a specific embodiment of the present invention, by extending the blade, the wind turbine can capture more wind energy, thereby improving the utilization rate of wind energy. The increase in blade length enables the blade to generate greater thrust at the same wind speed, thereby increasing the rotational speed and torque of the wind turbine, which helps to improve the overall operating efficiency of the wind turbine. Through optimization design and finite element analysis, it can be ensured that the extended blade is more stable structurally, reducing the unstable factors that may be brought about by the increase in blade length. The optimized blade design can reduce the rotational speed within the same cycle, thereby reducing the degree of mechanical wear and extending the service life of the wind turbine. By optimizing the shape and structure of the impeller and using more advanced composite materials, the noise generated during the operation of the wind turbine can be effectively reduced, thereby improving the operating environment and reducing the impact on the lives of surrounding residents. By increasing the utilization rate of wind energy and operating efficiency, the operating cost of the wind turbine is reduced. At the same time, the optimized blade design also means that the number of wind turbines required may be reduced, thereby further saving the manufacturing, installation, and maintenance costs. Increasing the utilization rate of wind energy means reducing the dependence on fossil fuels, thereby reducing greenhouse gas emissions, which helps to achieve the goals of sustainable development and addressing climate change.

[0060] In a preferred embodiment of the present invention, in the above step 11, obtaining the overall structure of the wind turbine and the blade profile, and obtaining the wind turbine parameters includes:

[0061] Step 111: Collect wind condition data, obtain wind condition parameters, and determine the start-up wind speed, rated wind speed, and cut-out wind speed of the wind turbine;

[0062] Step 112: Design the overall structure of the wind turbine rotor according to the wind speed to determine the parameters of the rotor diameter, height, and rated speed. The overall structure of the wind turbine rotor includes blades, small wings, rotating arms, small wing yaw mechanisms, and rotating arm deployment and telescoping mechanisms.

[0063] In a specific embodiment of the present invention, collecting wind condition data and obtaining wind condition parameters helps to accurately understand the local wind energy resources. Designing the overall structure of the wind turbine rotor according to the wind speed can ensure that parameters such as the rotor diameter, height, and rated speed match the actual wind conditions, which helps to improve the overall performance and power generation efficiency of the wind turbine. By precisely designing the overall structure of the wind turbine rotor, including components such as blades, small wings, and rotating arms, the structural stability and operating smoothness of the wind turbine can be improved. A reasonable design of the wind turbine rotor structure helps to reduce the failure rate during the operation of the wind turbine. By optimizing the layout and parameters of each component, problems such as stress concentration and excessive vibration can be reduced, thereby improving the reliability of the wind turbine. The optimized wind turbine rotor design can reduce the maintenance requirements and failure frequency of the wind turbine, thereby reducing the operating cost and maintenance cost. By continuously optimizing the wind turbine rotor structure design, the application of new materials, new processes, and new technologies in the wind power field can be promoted, further promoting the breakthrough and development of wind power technology.

[0064] The specific implementation steps of the present invention include:

[0065] Step 111: According to the installation location of the wind turbine, select representative wind condition data collection points that can reflect various wind conditions that the wind turbine may encounter during operation; install meteorological instruments such as anemometers and wind vanes at the selected collection points, start the meteorological instruments, and conduct continuous wind condition data collection. The collected data should include information such as wind speed and wind direction at different time periods; statistically analyze the collected wind condition data to determine the cut-in wind speed, rated wind speed, and cut-out wind speed of the wind turbine. By analyzing the wind speed distribution, determine the minimum wind speed at which the wind turbine can start generating electricity. According to the frequency distribution of the wind speed, determine the wind speed value when the wind turbine reaches the rated power. To protect the safety of the wind turbine, set a maximum operating wind speed. When the actual wind speed exceeds this value, the wind turbine will stop or take other safety measures.

[0066] Step 112: Based on the wind condition parameters determined in Step 111, clarify the goals of the wind turbine rotor design, including power generation efficiency, structural strength, and reliability. According to the design goals and wind speed data, conduct a preliminary design of the wind turbine rotor, including determining the approximate diameter, height, and rated speed range of the wind turbine rotor. Adopt aerodynamic design principles to optimize the shape and twist angle distribution of the blades to improve the wind energy conversion efficiency, and consider the structural strength and material selection of the blades. Add small wings to the blades as needed to improve the performance of the wind turbine rotor at certain wind speeds. Design the rotating arm connecting the blades and the main shaft to ensure that it has sufficient strength and stiffness to withstand various loads during operation, so as to achieve flexible adjustment of the small wings and the rotating arm.

[0067] In a preferred embodiment of the present invention, in step 12, by analyzing the influence of the wind turbine parameters on the blade profile, calculating the tip speed ratio, and obtaining the blade chord length and airfoil parameters to construct a three-dimensional model of the blade, including:

[0068] Step 121, according to the wind turbine parameters and the wind condition parameters, through calculate the lift on each blade element, and through calculate the drag on each blade element, and combine the lift on each blade element and the drag on each blade element to obtain the aerodynamic force on each blade element, where F L is the lift, F D is the drag, ρ is the air density, c(r) is the chord length of the blade element, V is the incoming flow velocity, r is the distance from the blade element to the center of the wind turbine, ω is the angular velocity of the wind turbine, C l (α(r)) is the lift coefficient, Y a is the angle between the axis of rotation of the wheel and the wind direction, dr is the width of a small segment on the blade, Cl and C d (α(r)) are the lift coefficient and the drag coefficient respectively, and T i is the turbulence intensity coefficient;

[0069] Step 122, according to the wind turbine parameters and the wind condition parameters, through obtain the velocity change of the airflow after passing through the blade, where v a is the axial induction velocity, V is the incoming flow velocity, and C T is the thrust coefficient;

[0070] Step 123, according to the aerodynamic force on each blade element and the velocity change of the airflow after passing through the blade, through calculate the tip speed ratio, the blade chord length, and the airfoil parameters, where λ is the tip speed ratio, ω is the angular velocity of the wind turbine, R is the radius of the wind turbine, and V1 is the upstream wind speed;

[0071] Step 124, construct a three-dimensional model of the blade according to the tip speed ratio, the blade chord length, and the airfoil parameters.

[0072] In a specific embodiment of the present invention, the lift and drag on each blade element are calculated in detail, thereby obtaining accurate aerodynamic data, so that the designer can more accurately understand the aerodynamic performance of the blade under different wind conditions, providing a reliable basis for subsequent optimization design. By calculating the speed change after the airflow passes through the blade, the designer can evaluate the acceleration or deceleration effect of the blade on the airflow. The tip speed ratio, blade chord length and airfoil parameters are calculated, and based on the precise parameters obtained, a three-dimensional model of the blade can be quickly constructed. Comprehensively considering multiple aspects such as the aerodynamic performance, speed change, and tip speed ratio of the blade, and performing comprehensive performance optimization will help improve the wind energy utilization, operating stability and economic benefits of the wind turbine.

[0073] The specific implementation steps of the present invention include:

[0074] Step 121, collect the parameters of the wind rotor (diameter, height, rated speed, etc.) and wind condition parameters (such as wind speed), divide the blade into multiple tiny segments along its length direction, each segment is called a blade element. The position of each blade element is determined by its distance r to the center of the wind rotor. For each blade element, the lift and drag are calculated using the provided formula, which takes into account the air density, the chord length of the blade element, the incoming wind speed, the angular velocity of the blade element, the lift coefficient and the drag coefficient, and the angle between the wheel rotation axis and the wind direction. In addition, the influence of the turbulence intensity coefficient on the lift is also considered. The lift and drag vectors on all blade elements are synthesized through The total aerodynamic force on each blade element is obtained, where F L is the lift force, F D is the drag force and F is the total aerodynamic force.

[0075] Step 122, according to the design parameters and operating status of the wind wheel, determine the thrust coefficient, which reflects the thrust effect of the wind wheel on the airflow, and use the provided formula to calculate the axial induced velocity v after the airflow passes through the blades a , this speed change is caused by the thrust of the wind wheel on the airflow.

[0076] Step 123, according to the wind condition parameters, determine the upstream wind speed, that is, the wind speed in front of the wind rotor, and use the provided formula to calculate the tip speed ratio, which reflects the relationship between the linear velocity of the blade tip and the upstream wind speed. Based on the aerodynamic force calculated in step 121 and the speed change calculated in step 122, combined with the tip speed ratio, the chord length and airfoil parameters (such as airfoil thickness, camber, etc.) of each blade element are determined through design criteria.

[0077] Step 124, select 3D modeling software, and based on the tip speed ratio, blade chord length and airfoil parameters calculated in step 123, use the function of the modeling tool to draw the contour line of the blade, set the airfoil section, perform lofting or sweeping operations, and generate a 3D model of the blade.

[0078] In a preferred embodiment of the present invention, in step 13 above, based on the three-dimensional model of the blade, the aerodynamic shape design and aerodynamic load analysis of the blade are carried out to obtain the blade shape and load analysis results, including:

[0079] Step 131: Based on the three-dimensional model of the blade, carry out the aerodynamic shape design of the blade;

[0080] Step 132: Based on the aerodynamic shape of the blade, analyze the aerodynamic load of the blade in the wind field through CFD simulation to obtain the aerodynamic load results, and the aerodynamic load results include the power, power coefficient, torque and thrust received by the blade.

[0081] In a specific embodiment of the present invention, carrying out the aerodynamic shape design based on the three-dimensional model of the blade can ensure the optimization of the blade shape and size. Considering the principles of fluid dynamics, unnecessary air resistance is reduced, and the aerodynamic efficiency of the blade is improved. Through CFD simulation analysis, the aerodynamic load results of the blade in the wind field can be accurately obtained, including key parameters such as the power, power coefficient, torque and thrust received by the blade. Accurate aerodynamic load analysis helps to predict the performance of the wind turbine and evaluate its stability and safety under different wind conditions. The optimized aerodynamic shape of the blade and accurate aerodynamic load analysis work together to enable the wind turbine to capture wind energy more efficiently. By reducing energy loss and improving energy conversion efficiency, the power generation of the wind turbine is significantly increased. This not only reduces the cost per kilowatt-hour of wind power, but also improves the competitiveness of wind power in the energy market. Through detailed aerodynamic load analysis of the blade, potential stress concentration areas and fatigue failure risks can be identified at the design stage. This helps to take corresponding strengthening measures during the manufacturing process, thereby enhancing the structural strength and reliability of the wind turbine. Reducing the downtime due to failures and extending the service life of the wind turbine.

[0082] The specific implementation steps of the present invention include:

[0083] Step 131: First, obtain the three-dimensional model of the blade constructed in step 12, which can accurately reflect the geometric shape and details of the blade. Use CFD tools to optimize the aerodynamic shape of the blade, including adjusting the twist angle distribution, chord length distribution, airfoil selection, etc. of the blade to improve the aerodynamic performance of the blade; during the design process, follow certain design criteria, such as maximizing the wind energy capture efficiency, reducing aerodynamic resistance, and improving structural strength, etc. And carry out multiple iterations during the design process. After each iteration, use CFD tools to carry out simulation analysis, and adjust the design parameters according to the analysis results until satisfactory aerodynamic performance is achieved. After completing the aerodynamic shape design, output the final design drawings and three-dimensional model.

[0084] Step 132: Set the analysis conditions in the CFD tool, including the incoming flow velocity, wind direction, turbulence intensity, etc. Perform mesh generation on the three-dimensional blade model to generate the required mesh system for calculation. Set appropriate boundary conditions for the CFD simulation, such as the inlet boundary, outlet boundary, and wall boundary. Start the CFD simulation, observe and analyze the aerodynamic load conditions of the blade in the wind field, including key parameters such as the pressure distribution and velocity distribution on the blade surface. Extract the aerodynamic load data from the simulation results, including the power, power coefficient, torque, and thrust exerted on the blade.

[0085] In a preferred embodiment of the present invention, for the above step 14, according to the blade shape and load analysis results, to construct a blade finite element model, including:

[0086] Step 141: According to the blade shape and load analysis results, including the geometric shape, dimensions, material properties of the blade, and the aerodynamic loads under different wind speeds and wind directions;

[0087] Step 142: According to the blade shape and load analysis results, select the ANSYS finite element analysis software and establish the geometric model of the blade;

[0088] Step 143: According to the geometric model of the blade, determine the material properties of the blade model and the boundary conditions of the model,

[0089] Step 144: Perform mesh generation on the blade geometric model, and conduct finite element analysis according to the material properties of the blade model and the boundary conditions of the model to simulate the stress conditions of the blade in the actual wind field, so as to obtain data on stress distribution and deformation conditions;

[0090] Step 145: According to the data on stress distribution and deformation conditions, to construct a blade finite element model.

[0091] In a specific embodiment of the present invention, the geometric shape, dimensions, material properties of the blade, and the aerodynamic loads under different conditions are comprehensively considered, providing comprehensive input data for subsequent establishment of an accurate finite element model. Through finite element analysis, the stress conditions of the blade in the actual wind field can be simulated, and detailed data on stress distribution and deformation conditions can be obtained, so that the performance of the blade can be accurately predicted at the design stage. The material properties and boundary conditions of the blade model are determined to improve the strength and durability of the blade. Through the analysis of stress distribution and deformation conditions, the structural design of the blade can be optimized to reduce the risk of stress concentration and potential fatigue failure. Through finite element analysis, potential structural problems can be discovered and solved at the design stage, thereby improving the reliability of the product before actual manufacturing. An accurate finite element model can help engineers predict the behavior of the blade under different wind conditions and ensure its safe operation under various conditions. Conducting sufficient finite element analysis at the design stage can reduce the need for physical prototype testing.

[0092] The specific implementation steps of the present invention include:

[0093] Step 141, collect the geometric shape, dimensions, material properties of the blade, and the aerodynamic load data under different wind speeds and wind directions from the above steps, and sort out the collected data, including the external shape data of the blade (such as twist angle, chord length, airfoil, etc.) and the load data (such as power, torque, thrust, etc.).

[0094] Step 142, select the ANSYS finite element analysis software, and gradually establish the geometric model of the blade in ANSYS by using the sorted blade external shape data in Step 141.

[0095] Step 143, set the corresponding material properties in ANSYS according to the material of the blade design, such as elastic modulus, Poisson's ratio, density; according to the constraint conditions of the blade during actual operation (such as root fixed, tip free, etc.), set the corresponding boundary conditions on the model.

[0096] Step 144, perform mesh division on the blade geometric model to generate a mesh system for finite element analysis, apply the aerodynamic load data collected in Step 141 to the blade model to simulate the stress situation of the blade in the actual wind field, start the finite element analysis, and observe and analyze the stress distribution, deformation situation, etc. of the blade under the given load and boundary conditions.

[0097] According to the pre-set wolf pack size (for example, set to N wolves), randomly generate initial mesh division parameters for each wolf, and these parameters serve as the positions of the wolves, and certain physical constraints need to be satisfied, such as the mesh size cannot be less than a certain minimum value and cannot be greater than a certain maximum value to ensure the rationality of the mesh division. For example, for the mesh size h, its range can be set as [h min , h max , for the mesh density ρ, its range can be set as [ρ min , ρ max , the initial position of each wolf can be expressed as [h i , ρ i , where i represents the i-th wolf, and h min ≤h i ≤h max , ρ min ≤ρ i ≤ρ max .

[0098] For each grid division scheme represented by a wolf, perform grid division operations using ANSYS; conduct finite element analysis on the blade geometric model with the divided grid, apply the aerodynamic load data collected in step 141 to the model, and set the material properties and boundary conditions; start the finite element analysis to obtain data such as stress distribution and deformation conditions.

[0099] Calculate the fitness according to the fitness function. The exploring wolf searches within the search space and updates its position. The calculation formula for the fitness function F is:

[0100]

[0101] Among them, w1 represents the weight of the accuracy of the analysis result; E represents the sum of the squares of the errors between the analysis result and the theoretical expectation; ∈ represents a small positive number used to avoid the denominator being zero, ensuring that the denominator of the fitness function is not zero when the sum of the squares of the errors E is close to zero; w2 represents the weight; T represents the calculation time of the finite element analysis, and a shorter T value indicates higher calculation efficiency; δ represents a small positive number used to adjust the influence of the calculation time term, ensuring that the denominator of the fitness function is not zero when the calculation time T is close to zero; w3 represents the weight of the grid quality; w a represents the weight of the shape factor; l min represents the minimum side length in the grid; l max represents the maximum side length in the grid; w β represents the weight of the size distribution uniformity; σ A represents the standard deviation of the grid cell area; μ A represents the average value of the grid cell area, used to calculate the ratio of the standard deviation to the average value of the area; w γ represents the weight of the twist; J min represents the minimum value of the Jacobian determinant in the grid cell; J max represents the maximum value of the Jacobian determinant in the grid cell.

[0102] For the new position, it is necessary to check whether the physical constraints are met. If not, adjust it to the constraint range; evaluate the fitness of the mesh division scheme represented by the new position. If the new fitness is better than the original, update the position and fitness of the exploring wolf; the fierce wolf updates its own position according to the position of the leading wolf; check the constraints and evaluate the fitness of the new position. If it is better, update the position and fitness; after each iteration, compare the fitness of all wolves and update the wolf with the highest fitness as the leading wolf. After multiple iterations, the mesh division scheme corresponding to the position of the leading wolf is the optimal scheme. Use the optimal mesh division scheme represented by the position of the leading wolf to perform the final mesh division operation on the blade geometric model, and perform finite element analysis according to the conventional steps, including applying loads, setting boundary conditions, and starting the analysis to obtain the final stress distribution and deformation data.

[0103] Step 145: Extract key data such as stress distribution and deformation from the finite element analysis results, compare and verify the finite element analysis results with the experimental results. If significant differences or unreasonable points are found, adjust the model settings and re - perform the analysis. Based on the verified finite element analysis results, construct the final blade finite element model.

[0104] In a preferred embodiment of the present invention, in the above step 15, according to the blade finite element model, perform finite element simulation analysis on the blade under different working conditions to obtain finite element analysis results, including:

[0105] Step 151: Determine the objectives and working conditions of the simulation analysis;

[0106] Step 152: According to the objectives and working conditions of the simulation analysis, set the boundary conditions and loads for the finite element model simulation analysis of the blade;

[0107] Step 153: According to the boundary conditions and loads of the simulation analysis, perform finite element simulation analysis on the blade under different working conditions to obtain stress distribution, maximum stress value, deformation and natural frequency to evaluate the structural strength and stiffness of the blade;

[0108] Step 154: Perform local buckling simulation analysis on the blade to evaluate the buckling safety factor;

[0109] Step 155: According to the structural strength and stiffness of the blade and the buckling safety factor, obtain the finite element analysis results.

[0110] In a specific embodiment of the present invention, finite element simulation analysis is performed on the blade under different working conditions to obtain the stress distribution, maximum stress value, deformation condition, and natural frequency of the blade. By performing local buckling simulation analysis on the blade, the buckling safety factor can be evaluated, thereby preventing potential buckling risks at the design stage and improving the safety of the blade. The results of the finite element simulation analysis can provide valuable feedback to designers, helping them optimize the structural design of the blade at the design stage to improve its performance in practical applications. Through detailed finite element simulation analysis, the need for physical prototype testing can be reduced to a certain extent, thereby saving time, cost, and resources. Conducting detailed simulation analysis before the product is launched into the market helps to discover and correct defects in the design, thereby ensuring the quality and performance of the final product.

[0111] The specific implementation steps of the present invention include:

[0112] Step 151, determine the specific objectives of the simulation analysis, such as evaluating the structural strength, stiffness, and buckling safety of the blade; according to the environmental conditions that the blade may encounter during actual operation, define a series of working conditions for the simulation analysis, and these working conditions cover key factors such as different wind speeds, wind directions, and turbulence intensities.

[0113] Step 152, according to the working conditions defined in Step 151, set the corresponding boundary conditions for the blade finite element model. The boundary conditions include the fixed constraint at the blade root and the degrees of freedom at the blade tip. According to the working condition conditions, apply the corresponding aerodynamic loads on the blade finite element model, and the loads should be able to reflect the actual force conditions of the blade under different wind speeds and wind directions.

[0114] Steps 153 - 154, start the finite element analysis software, perform simulation analysis on the blade under different working conditions, observe and record key data such as stress distribution, maximum stress value, deformation condition, and natural frequency during the analysis process. Conduct detailed data analysis on the simulation results, evaluate the structural strength and stiffness of the blade, determine the key areas where local buckling may occur according to the finite element simulation results in the steps, set the boundary conditions and loads required for buckling analysis for these key areas, perform local buckling simulation analysis, evaluate the buckling safety of the blade, and record key data such as the buckling safety factor.

[0115] In finite element simulation analysis, the stress distribution refers to the magnitudes and directions of stresses at different positions on the blade structure. The maximum stress value is the maximum stress that appears in the entire blade structure and is used to check whether the material exceeds its allowable stress, thereby determining whether the structure is safe. The deformation condition is the shape change of the blade under the action of loads. Excessive deformation may affect the function and safety of the blade. The natural frequency is the frequency at which the blade vibrates naturally without external excitation and is used to evaluate whether the blade is prone to resonance with external excitations (such as wind, mechanical vibration, etc.). The buckling safety factor is the ratio between the ability of the blade structure to resist buckling instability and the actual applied load and is used to evaluate whether the blade will undergo buckling instability when subjected to compressive loads.

[0116] Generally, based on the linear elastic theory, the finite element method is used to solve the response of the blade under given boundary conditions and loads. The finite element method involves discretizing the structure into many small elements and solving for the stresses and deformations within each element, and involves solving the eigenvalue problem of the blade structure to determine its natural vibration frequency and modal shape, usually by comparing the critical buckling load of the blade with the actual working load. If FS > 1, the structure is safe; if FS < 1, the structure may undergo buckling.

[0117] Step 155: Aggregate all the data obtained in Steps 153 and 154, including the stress distribution, maximum stress value, deformation condition, natural frequency, and buckling safety factor, and conduct a comprehensive analysis of the aggregated data to evaluate the overall performance of the blade under different working conditions. Pay special attention to possible performance bottlenecks or safety hazards.

[0118] In a preferred embodiment of the present invention, in Step 16 above, based on the finite element analysis results, an extended optimization design is performed on the blade to obtain the extended optimization result of the wind turbine blade, including:

[0119] Step 161: According to the finite element analysis results, adjust the blade length and change the airfoil to achieve blade extension;

[0120] Step 162: According to the load analysis results, adjust the geometric shape and material distribution of the extended part of the blade to minimize stress concentration and deformation to obtain the extended optimization result of the wind turbine blade.

[0121] In a specific embodiment of the present invention, by adjusting the blade length and changing the airfoil, the extension of the blade can be achieved, enabling the blade to capture more wind energy at the same wind speed, thereby improving the wind energy utilization rate. According to relevant research, the increase in blade length can effectively improve the thrust and rotational speed of the wind turbine, and thus enhance the conversion efficiency of wind energy. Adjusting the geometric shape and material distribution of the extended part of the blade according to the load analysis results helps to minimize stress concentration and deformation, not only improving the structural safety of the blade, but also enabling the blade to transfer forces more evenly and efficiently when bearing loads, thereby reducing unnecessary energy losses. By optimizing the extended design of the blade, mechanical wear and fatigue damage during blade operation can be reduced. The adjustment of the geometric shape and material distribution of the extended part helps to reduce the occurrence of stress concentration areas, thus extending the service life of the blade. The optimized extended design of the blade helps to improve the overall performance of the wind turbine. Longer blades can generate greater thrust, increase the rotational speed and torque of the wind turbine, and thus enhance the operating efficiency of the wind turbine. At the same time, the optimized blade design can also reduce the operating cost of the wind turbine and environmental pollution. Since the optimized extended design of the blade improves its structural durability and service life, the maintenance frequency and repair cost of the wind turbine can be reduced.

[0122] The specific implementation steps of the present invention include:

[0123] Step 161: Examine in detail the finite element analysis results obtained in Step 15, especially the data on blade stress distribution, deformation conditions, and natural frequencies. According to the requirements for improving the performance of the wind turbine, determine the specific objectives for blade extension, such as the percentage increase in length or the specific length to be achieved. On the premise of maintaining the overall structural stability of the blade, gradually increase the blade length by extending the tip of the blade or adding new blade segments to the existing blade. Determine the airfoil according to the extended blade length and expected aerodynamic performance.

[0124] Step 162: Based on the preliminary verification results in Step 161, identify the key areas with significant stress concentration or large deformation in the extended part. For these key areas, make fine adjustments to the geometric shape, including adjusting the local thickness, chord length, or twist angle of the airfoil, to improve the stress distribution and reduce deformation. Optimize the material distribution according to the stress distribution and deformation conditions of the blade. For example, use higher-strength materials in areas with stress concentration, while lighter materials can be used in areas with lower stress to achieve a balance between weight and strength. Conduct multiple rounds of finite element analysis, and adjust the geometric shape and material distribution of the blade according to the results after each analysis. Through this iterative optimization method, gradually approach the optimal extended design scheme. Conduct a comprehensive finite element analysis of the optimized extended blade to ensure its structural safety, aerodynamic performance, and manufacturing feasibility during actual operation. At the same time, evaluate the improvement effect of the optimization results on the overall performance of the wind turbine.

[0125] As Figure 2 shown, an embodiment of the present invention further provides an optimization system for extending a wind turbine blade based on finite element analysis, including:

[0126] An acquisition module for acquiring the overall structure of the wind rotor and the blade profile, and acquiring wind rotor parameters;

[0127] An analysis module for calculating the tip speed ratio by analyzing the influence of wind rotor parameters on the blade profile, acquiring the blade chord length and airfoil parameters to construct a three-dimensional model of the blade; performing aerodynamic shape design and aerodynamic load analysis on the blade according to the three-dimensional model of the blade to obtain the blade profile and load analysis results;

[0128] An optimization module for constructing a finite element model of the blade according to the blade profile and load analysis results; performing finite element simulation analysis on the blade under different working conditions according to the finite element model of the blade to obtain finite element analysis results; performing extension optimization design on the blade based on the finite element analysis results to obtain the optimization result of extending the wind turbine blade.

[0129] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for optimizing the extension of a fan blade based on finite element analysis, characterized in that, The method includes: Obtain the overall structure of the wind turbine rotor and the blade profile, and obtain the wind turbine rotor parameters; By analyzing the influence of the wind turbine rotor parameters on the blade profile, calculate the tip speed ratio, obtain the blade chord length and airfoil parameters, and construct a three-dimensional model of the blade; According to the three-dimensional model of the blade, conduct blade aerodynamic shape design and aerodynamic load analysis to obtain the blade shape and load analysis results; According to the blade shape and load analysis results, construct a finite element model of the blade; According to the finite element model of the blade, conduct finite element simulation analysis on the blade under different working conditions to obtain the finite element analysis results; Based on the finite element analysis results, conduct extended optimization design on the blade to obtain the extended optimization results of the wind turbine blade.

2. The method for optimizing the extension of a fan blade based on finite element analysis according to claim 1, wherein, Obtain the overall structure of the wind turbine rotor and the blade profile, and obtain the wind turbine rotor parameters, including: Collect wind condition data, obtain wind condition parameters, and determine the cut-in wind speed, rated wind speed, and cut-out wind speed of the wind turbine; According to the wind speed, design the overall structure of the wind turbine rotor to determine the diameter, height, and rated rotational speed parameters of the wind turbine rotor. The overall structure of the wind turbine rotor includes blades, winglets, rotating arms, winglet yaw mechanisms, and rotating arm deployment and telescoping mechanisms.

3. The method for optimizing the extension of a fan blade based on finite element analysis according to claim 2, wherein, By analyzing the influence of the wind turbine rotor parameters on the blade profile, calculate the tip speed ratio, obtain the blade chord length and airfoil parameters, and construct a three-dimensional model of the blade, including: According to the wind turbine rotor parameters and wind condition parameters, calculate the lift on each blade element and the drag on each blade element; Combine the lift on each blade element and the drag on each blade element to obtain the aerodynamic force on each blade element; According to the wind turbine rotor parameters and wind condition parameters, calculate the velocity of the airflow after passing through the blade; According to the aerodynamic force on each blade element and the velocity of the airflow after passing through the blade, calculate the tip speed ratio, blade chord length, and airfoil parameters; According to the tip speed ratio, blade chord length, and airfoil parameters, construct a three-dimensional model of the blade.

4. The method for optimizing the extension of a fan blade based on finite element analysis according to claim 3, wherein According to the three-dimensional model of the blade, conduct blade aerodynamic shape design and aerodynamic load analysis to obtain the blade shape and load analysis results, including: According to the three-dimensional model of the blade, conduct the design of the blade aerodynamic shape; According to the blade aerodynamic shape, analyze the aerodynamic load of the blade in the wind field through CFD simulation to obtain the aerodynamic load results. The aerodynamic load results include the power, power coefficient, torque, and thrust received by the blade.

5. The method for optimizing the extension of a fan blade based on finite element analysis according to claim 4, wherein According to the blade shape and load analysis results, construct a finite element model of the blade, including: According to the blade shape and load analysis results, including the geometric shape, dimensions, material properties of the blade, and the aerodynamic load under different wind speeds and wind directions; According to the blade shape and load analysis results, establish a geometric model of the blade; According to the geometric model of the blade, determine the material properties of the blade model and the boundary conditions of the model; Perform mesh division on the blade geometric model, conduct finite element analysis according to the material properties of the blade model and the boundary conditions of the model, simulate the stress situation of the blade in the actual wind field, and obtain the stress distribution and deformation data; According to the stress distribution and deformation data, construct a finite element model of the blade.

6. The method for optimizing the extension of a fan blade based on finite element analysis according to claim 5, wherein, According to the finite element model of the blade, conduct finite element simulation analysis on the blade under different working conditions to obtain the finite element analysis results, including: Determine the objectives and working conditions of the simulation analysis; Set the boundary conditions and loads for the finite element model simulation analysis of the blade according to the objectives and working conditions of the simulation analysis. Conduct finite element simulation analysis on the blade under different working conditions according to the boundary conditions and loads of the simulation analysis to obtain the stress distribution, maximum stress value, deformation condition, and natural frequency, so as to evaluate the structural strength and stiffness of the blade. Conduct local buckling simulation analysis on the blade to evaluate the buckling safety factor. Obtain the finite element analysis results based on the structural strength and stiffness of the blade and the buckling safety factor.

7. The method for optimizing the extension of a fan blade based on finite element analysis according to claim 6, wherein Based on the finite element analysis results, conduct extended optimization design on the blade to obtain the extended optimization results of the fan blade, including: Adjust the blade length and change the airfoil according to the finite element analysis results to achieve blade extension. Adjust the geometric shape and material distribution of the extended part of the blade according to the load analysis results to minimize stress concentration and deformation, so as to obtain the extended optimization results of the fan blade.

8. A fan blade extension optimization system based on finite element analysis, characterized in that, The system is used to execute the method described in any one of claims 1 to 7, including: An acquisition module for acquiring the overall structure of the wind turbine rotor and the blade profile, and acquiring wind turbine rotor parameters. An analysis module for calculating the tip speed ratio by analyzing the influence of wind turbine rotor parameters on the blade profile, obtaining the blade chord length and airfoil parameters to construct a three-dimensional model of the blade; conducting aerodynamic shape design and aerodynamic load analysis of the blade based on the three-dimensional model of the blade to obtain the blade profile and load analysis results. An optimization module for constructing a finite element model of the blade according to the blade profile and load analysis results; conducting finite element simulation analysis on the blade under different working conditions based on the finite element model of the blade to obtain the finite element analysis results; conducting extended optimization design on the blade based on the finite element analysis results to obtain the extended optimization results of the fan blade.

9. A computing device, characterized in that, Including: One or more processors; A storage device for storing one or more programs, which when executed by the one or more processors cause the one or more processors to implement the method described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, A program is stored in the computer-readable storage medium, and when the program is executed by a processor, the method described in any one of claims 1 to 7 is implemented.

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