Blade roughness evaluation method and device of wind generating set and storage medium

Abstract

The invention provides a blade roughness evaluation method and device of a wind generating set and a storage medium. The blade roughness evaluation method comprises the steps that the roughness profile of a target section of a target blade is determined; processing the roughness profile by using a cycle counting method to obtain a plurality of groups of cycle data corresponding to each set point in a plurality of set points on the target cross section, each group of cycle data including roughness amplitude and cycle times; a circulation threshold value corresponding to the roughness amplitude value is obtained, and the circulation threshold value represents the number of cycles experienced when the airflow flows along the blade with the roughness amplitude value and reaches the transition state; and determining a transition point of the target section from the plurality of set points according to the plurality of groups of cycle data corresponding to each set point in the plurality of set points and the corresponding cycle threshold value, so as to evaluate the influence of the roughness of the target section on the aerodynamic performance of the blade. According to the invention, the transition point can be reasonably determined based on the physical association between the roughness and transition, and effective evaluation of the roughness is realized.

Description

Technical Field

[0001] The present disclosure relates to the field of wind power generation, and more particularly, to a method, device, and storage medium for evaluating the roughness of a blade of a wind turbine generator set. Background Art

[0002] A wind turbine generator set is a clean energy system used to capture wind energy and convert it into electrical energy. When an air flow passes through the wind turbine blades of the wind turbine generator set, a thrust is generated on the blade surface, which then drives the wind wheel to rotate, converting the kinetic energy of the wind into the kinetic energy of the wind wheel. The rotating wind wheel then drives the generator to rotate, converting the kinetic energy of the wind wheel into electrical energy.

[0003] The roughness of the blade surface has a great influence on the blade performance. The increase in roughness means the decrease in blade performance, resulting in the decline of the wind energy capture ability and affecting the power generation efficiency. Usually, when the blade leaves the factory, the roughness of its surface is measured, and some given evaluation parameters are selected, such as the arithmetic mean value of the roughness profile, the maximum height of the roughness profile, etc., to determine whether it meets the processing standards. These tests usually limit the blade surface from the processing perspective of the process, but the actual influence on the aerodynamic performance of the blade is not considered. Summary of the Invention

[0004] Therefore, how to effectively evaluate the influence of the blade surface roughness on the blade aerodynamic performance is crucial for improving the power generation efficiency of the wind turbine generator set.

[0005] In one general aspect, there is provided a method for evaluating the roughness of a blade of a wind turbine generator set. The method for evaluating the roughness of the blade includes: determining the roughness profile of a target cross-section of a target blade, where the target cross-section is a cross-section perpendicular to the span direction of the blade; processing the roughness profile using a cycle counting method to obtain multiple sets of cycle data corresponding to each of multiple set points on the target cross-section, where each set of cycle data includes a roughness amplitude and a cycle number; obtaining a cycle threshold corresponding to the roughness amplitude, where the cycle threshold represents the number of cycles experienced when the air flow flows along the blade with the roughness amplitude until it reaches the transition state; and determining a transition point of the target cross-section from the multiple set points according to the multiple sets of cycle data corresponding to each of the multiple set points and the corresponding cycle threshold, so as to evaluate the influence of the roughness of the target cross-section on the blade aerodynamic performance.

[0006] Optionally, determining the roughness profile of the target cross-section of the target blade includes: for each of a plurality of set points on the target cross-section of the target blade, determining the roughness profile from the stagnation point of the target cross-section to the set point; and processing the roughness profile using the cycle counting method to obtain multiple sets of cycle data corresponding to each of the plurality of set points on the target cross-section, including: processing the roughness profile corresponding to each of the plurality of set points using the cycle counting method to obtain multiple sets of cycle data corresponding to the set point.

[0007] Optionally, determining the roughness profile of the target cross-section of the target blade further includes: obtaining the roughness measurement values of a plurality of points on the target cross-section; determining the stagnation points corresponding to the target cross-section at multiple angles of attack, and a plurality of set points located downstream of the stagnation points; and for each of the plurality of set points on the target cross-section of the target blade, determining the roughness profile from the stagnation point of the target cross-section to the set point, including: for each stagnation point on the target cross-section of the target blade and each corresponding set point, based on the roughness measurement values of the plurality of points, determining the roughness profile from the stagnation point to the set point.

[0008] Optionally, determining the transition point of the target cross-section from the plurality of set points according to the multiple sets of cycle data corresponding to each of the plurality of set points and the corresponding cycle threshold includes: for each of the plurality of set points, statistically processing the set ratios corresponding to each group of cycle data to obtain the set ratio statistical value of the set point, where the set ratio is the ratio of the number of cycles to the cycle threshold; and determining the transition point of the target cross-section from the plurality of set points according to the set ratio statistical values of each of the plurality of set points.

[0009] Optionally, determining the transition point of the target cross-section from the plurality of set points according to the set ratio statistical values of each of the plurality of set points includes: sorting the plurality of set points in ascending order of the distance from the stagnation point of the target cross-section, and comparing the set ratio statistical value of each set point with the statistical value threshold one by one; and determining the set point corresponding to the first set ratio statistical value greater than or equal to the statistical value threshold as the transition point of the target cross-section.

[0010] Optionally, the chordwise spacing between any one of the plurality of set points and the leading edge of the target cross-section is less than or equal to a set spacing.

[0011] Optionally, the target blade is a wind turbine blade that has been designed; or the target blade is a standard airfoil blade with a unit length.

[0012] In another general aspect, a blade roughness evaluation device is provided. The blade roughness evaluation device includes: a profile determination unit configured to determine a roughness profile of a target cross-section of a target blade, where the target cross-section is a cross-section perpendicular to the spanwise direction of the blade; a cycle counting unit configured to process the roughness profile using a cycle counting method to obtain multiple sets of cycle data corresponding to each of multiple set points on the target cross-section, where each set of cycle data includes a roughness amplitude and a number of cycles; a threshold acquisition unit configured to acquire a cycle threshold corresponding to the roughness amplitude, where the cycle threshold represents the number of cycles experienced to reach a transition state when an air flow flows along a blade with the roughness amplitude; and a transition determination unit configured to determine a transition point of the target cross-section from the multiple set points according to the multiple sets of cycle data corresponding to each of the multiple set points and the corresponding cycle thresholds, so as to evaluate the influence of the roughness of the target cross-section on the aerodynamic performance of the blade.

[0013] Optionally, the profile determination unit is further configured to, for each of the multiple set points on the target cross-section of the target blade, determine a roughness profile from the stagnation point of the target cross-section to the set point; the cycle counting unit is further configured to process the roughness profile corresponding to each of the multiple set points using a cycle counting method to obtain multiple sets of cycle data corresponding to the set point.

[0014] Optionally, the profile determination unit is further configured to: acquire roughness measurement values of multiple points on the target cross-section; determine the stagnation point corresponding to the target cross-section at multiple angles of attack, and multiple set points located downstream of the stagnation point; and for each stagnation point and its corresponding set point on the target cross-section of the target blade, determine a roughness profile from the stagnation point to the set point based on the roughness measurement values of the multiple points.

[0015] Optionally, the transition determination unit is further configured to: for each of the multiple set points, perform statistical processing on the set ratios corresponding to each set of cycle data to obtain a set ratio statistical value of the set point, where the set ratio is the ratio of the number of cycles to the cycle threshold; and determine the transition point of the target cross-section from the multiple set points according to the set ratio statistical values of each of the multiple set points.

[0016] Optionally, the transition determination unit is further configured to: sort the multiple set points in ascending order of the distance from the stagnation point of the target cross-section, and compare the set ratio statistical value of each set point with a statistical value threshold one by one; and determine the set point corresponding to the first set ratio statistical value greater than or equal to the statistical value threshold as the transition point of the target cross-section.

[0017] Optionally, the chordwise distance between any one of the plurality of set points and the leading edge of the target section is less than or equal to a set distance.

[0018] Optionally, the target blade is a blade of a wind turbine that has been designed; or the target blade is a standard airfoil blade with a unit length.

[0019] In another general aspect, there is provided a computer-readable storage medium which, when instructions in the computer-readable storage medium are run by at least one processor, causes the at least one processor to execute a method for evaluating the roughness of a blade of a wind turbine according to an embodiment of the present disclosure.

[0020] In another general aspect, there is provided a computer device including: at least one processor; and at least one memory storing computer-executable instructions, wherein the computer-executable instructions, when run by the at least one processor, cause the at least one processor to execute a method for evaluating the roughness of a blade of a wind turbine according to an embodiment of the present disclosure.

[0021] The present disclosure provides a method, an apparatus, and a storage medium for evaluating the roughness of a blade of a wind turbine. By performing cycle counting processing on the roughness profile of the blade and combining the cycle threshold corresponding to the roughness amplitude, a transition point is determined from multiple set points of the target section of the blade. Based on the physical relationship between roughness and transition, the transition point can be reasonably determined, which helps to evaluate the impact of roughness on the aerodynamic performance of the blade.

[0022] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. Description of the Drawings

[0023] Through the description of the embodiments in conjunction with the drawings below, the above and other objects and features of the present invention will become clearer. In the drawings:

[0024] Figure 1 is a schematic diagram of a roughness profile showing a sampling length;

[0025] Figure 2 is a flowchart showing a method for evaluating the roughness of a blade of a wind turbine according to an embodiment of the present disclosure;

[0026] Figure 3 is a schematic diagram of an airfoil showing a spanwise section;

[0027] Figure 4 is a block diagram showing an apparatus for evaluating the roughness of a blade of a wind turbine according to an embodiment of the present disclosure;

[0028] Figure 5is a block diagram showing a computer device according to an embodiment of the present disclosure. Detailed Description

[0029] The following detailed description is provided to assist the reader in obtaining a comprehensive understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely exemplary and is not limited to those set forth herein, but may be changed as will be apparent after understanding the disclosure of this application, except for operations that must occur in a particular order. In addition, descriptions of features known in the art may be omitted for greater clarity and conciseness.

[0030] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Instead, the examples described herein are provided only to illustrate some of the many possible ways of implementing the methods, devices, and / or systems described herein, which will be apparent after understanding the disclosure of this application.

[0031] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more of them.

[0032] Although terms such as "first", "second", and "third" may be used herein to describe various components, components, regions, layers, or parts, these components, components, regions, layers, or parts should not be limited by these terms. Instead, these terms are only used to distinguish one component, component, region, layer, or part from another component, component, region, layer, or part. Thus, a first component, a first component, a first region, a first layer, or a first part as referred to in the examples described herein may also be referred to as a second component, a second component, a second region, a second layer, or a second part without departing from the teachings of the examples.

[0033] In the specification, when an element (such as a layer, region, or substrate) is described as "on", "connected to", or "coupled to" another element, the element may be directly "on", directly "connected to", or "coupled to" the other element, or there may be one or more other elements in between. In contrast, when an element is described as "directly on", "directly connected to", or "directly coupled to" another element, there may be no other elements in between.

[0034] The terms used herein are for describing various examples only and are not intended to limit the disclosure. Unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. The terms "comprising", "including" and "having" specify the presence of the described features, quantities, operations, components, elements and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements and / or combinations thereof.

[0035] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains after understanding this disclosure. Unless clearly defined herein, terms (such as those defined in a general dictionary) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and shall not be interpreted in an idealized or overly formal manner.

[0036] Furthermore, in the description of the examples, when it is considered that a detailed description of the relevant structure or function that is well-known will cause a blurred interpretation of this disclosure, such detailed description will be omitted.

[0037] Surface roughness refers to the unevenness of smaller spacing and minute peaks and valleys on a machined surface, which is usually represented by the profile on a straight line of a specified length on the machined surface, denoted as the roughness profile. The specified length usually includes the sampling length and the evaluation length. The sampling length is a reference line length specified when measuring or evaluating surface roughness, and the evaluation length is the minimum length specified when measuring and evaluating surface roughness, generally including 5 sampling lengths. As Figure 1 shown is the roughness profile of a sampling length lr. Among them, the arithmetic mean value Ra of the profile refers to the arithmetic mean value of the absolute values of the ordinate values within a sampling length, and the maximum height Rz of the profile refers to the sum value of the maximum profile peak height and the maximum profile valley depth within a sampling length. In addition, for an evaluation length, there is also the total height Rt of the profile, which refers to the sum value of the maximum profile peak height and the maximum profile valley depth within the evaluation length.

[0038] Regarding the roughness of the blades of a wind turbine, the existing evaluation methods usually measure the roughness profile of the blade surface using measuring equipment at the time of factory shipment, first calculate parameters such as the arithmetic mean value of the profile and the maximum height of the profile, and then compare them with the corresponding standard values to determine whether the blade meets the processing standards, that is, evaluate from the perspective of process processing, without considering the influence of blade roughness on the aerodynamic performance of the blade. And during the actual operation of the unit, the profile line of the blade will change further due to contaminants, wear, etc., that is, the roughness changes, and the influence of these changes on the aerodynamic performance of the blade is not considered either.

[0039] Next, it will be combined withFigures 2 to 5 Introduce a method, device, and storage medium for evaluating the blade roughness of a wind turbine provided by an embodiment of the present disclosure.

[0040] An embodiment of one aspect of the present disclosure provides a method for evaluating the blade roughness of a wind turbine. Figure 2 It is a flowchart showing a method for evaluating the blade roughness of a wind turbine according to an embodiment of the present disclosure.

[0041] Refer to Figure 2 , in step S201, determine the roughness profile of the target cross-section of the target blade. Here, the target cross-section is a cross-section perpendicular to the span direction of the blade.

[0042] The target blade is the blade whose roughness is to be evaluated. The evaluation method of the present disclosure can be executed during the pre-factory evaluation or after the unit to which it belongs is put into operation, so as to be able to evaluate the roughness of the blade throughout its life cycle.

[0043] The blade of a wind turbine can actually be regarded as composed of several cross-sections (hereinafter referred to as spanwise cross-sections) perpendicular to the span direction (the span direction refers to the length direction of the blade). Figure 3 shows the airfoil of a spanwise cross-section. The flow of the air mainly occurs along the chord direction of the blade (the chord direction refers to the direction where the chord line of the airfoil is located at each spanwise cross-section of the blade. The chord line is the connection line between the leading edge and the trailing edge of the airfoil. Since the leading edge of the blade is often a curved surface, correspondingly, the leading edge of the airfoil is a curve. In order to determine a fixed chord line, the art usually uses a specific method to determine a point as the starting point of the chord line. Here, the leading edge herein refers to the point position determined as the starting point of the chord line from the leading edge curve of the airfoil of the spanwise cross-section, and the same hereinafter, and will not be reiterated). Therefore, the measurement of roughness is mainly based on the chord direction, and the measurement and evaluation of the overall roughness of the blade can be simplified to the measurement and evaluation of the roughness of several spanwise cross-sections. Based on this, the target cross-section is a spanwise cross-section of the target blade. In actual evaluation, the length of the blade often exceeds 100 meters, and the airfoils of each spanwise cross-section are often different. Some representative spanwise cross-sections can be selected to replace the entire blade. For example, a spanwise cross-section can be taken at a set interval (such as 1 meter or 2 meters) starting from the root of the blade as the cross-section to be evaluated. It should be understood that according to the blade roughness evaluation method of the exemplary embodiment of the present disclosure, only the data processing flow of one target cross-section is taken as an example for illustration. For the entire target blade, multiple selected spanwise cross-sections can be used as target cross-sections for evaluation respectively.

[0044] Optionally, the target blade is a wind turbine blade that has been designed; or the target blade is a standard airfoil blade with a unit length. By directly evaluating the actual blade that has been designed, targeted blade roughness evaluation can be achieved on demand, improving the accuracy of the evaluation. Since the airfoil of the actual blade is usually obtained by interpolation of a series of standard airfoils (the standard airfoil is the airfoil used as the design basis in blade design, such as the NACA (National Advisory Committee for Aeronautics) airfoil series), by evaluating the standard airfoil blade of unit length, the roughness evaluation result of the spanwise section of the actual blade can be inferred based on the evaluation result, which helps to reduce the calculation amount of the evaluation from an overall perspective.

[0045] In step S202, the roughness profile is processed using a cycle counting method to obtain multiple sets of cycle data corresponding to each of the multiple set points on the target cross section, wherein each set of cycle data includes a roughness amplitude and a cycle number.

[0046] The cycle counting method is usually used to deal with variable amplitude loads in fatigue analysis. It can convert loads with irregular amplitudes into several load cycles, and is characterized by the load mean and load amplitude of the cycles. All the converted load cycles can be classified, and then the number of cycles of each type of load cycle can be counted. This is consistent with the inherent characteristics of fatigue loads, and thus has a clear physical concept, realizing fatigue analysis for variable amplitude loads. From a physical point of view, the reason why the roughness of the blades of wind turbines affects the aerodynamic performance of the blades is that the slight unevenness of the blade surface along the airflow direction affects the flow state of the airflow, and this effect is mainly reflected in where the airflow flowing along the blade surface changes from laminar flow to turbulent flow (that is, where the airflow transition is triggered on the blade surface). The transition of the airflow to a certain set point can be compared to the fatigue life of a component just reaching the end of its life after being subjected to a certain variable amplitude load. Therefore, the effect of blade roughness on airflow transition is similar to the effect of variable amplitude load on component fatigue life. By using the cycle counting method to process the roughness profile, multiple sets of cycle data corresponding to each set point are obtained, and the irregular roughness profile experienced by the airflow when flowing to the set point can be converted into a number of roughness cycles, which is similar to fatigue analysis of each set point, so that the state of the airflow when it flows to each set point can be analyzed, which helps to achieve roughness evaluation with physical concepts to reflect the impact of blade roughness on the aerodynamic performance of the blade. It should be understood that the multiple sets of cycle data corresponding to each set point describe the roughness cycle of the line segment experienced by the airflow flowing along the target section to the corresponding set point, rather than just describing the roughness cycle of the local line segment near the corresponding set point.

[0047] It should also be understood that, similar to the classification of load cycles, each set of cycle data represents a class of roughness cycles, and each class of roughness cycles is characterized by its roughness mean value (similar to the arithmetic mean of the profile in the related art) and roughness amplitude (similar to half of the maximum height of the profile in the related art). The number of cycles of this class of roughness cycles can be statistically obtained. Therefore, each set of cycle data can also include the roughness mean value.

[0048] As an example, the cycle counting method includes methods such as the rainflow counting method and the maximum-minimum counting method, which can be selected according to actual needs, and the present disclosure does not limit this. It should be understood that when performing fatigue analysis, the abscissa in the cycle counting method is time, and when performing roughness evaluation, the abscissa is as Figure 1 shown as the straight line position x to be evaluated, which does not affect the normal use of the cycle counting method. Since the cycle counting method is a mature existing technology, it will not be elaborated here.

[0049] In addition, as Figure 3 shown, the blade includes a suction surface and a pressure surface. When the blade is in the flow field, the flow tube of the air flow on the upper surface (suction surface) is thin, the flow velocity is fast, and the pressure is low; the flow tube of the air flow on the lower surface (pressure surface) of the blade is thick, the flow velocity is slow, and the pressure is high. The pressure difference between the two surfaces generates an upward lift force, which in turn drives the wind turbine to rotate. More specifically, the point where the air flow is stationary when it contacts the blade surface is called the stagnation point. The stagnation point is usually near the leading edge and will change with conditions such as the airfoil and the oncoming flow situation, and is not a fixed point. Figure 3 The stagnation point is schematically marked. When the air flow reaches the stagnation point, the air flow separates into two parts from here. One part flows along the suction surface, and the other part flows along the pressure surface. The stagnation point serves as the starting point for distinguishing the suction surface and the pressure surface, that is, the starting point for the air flow to flow along the target cross-section. That is, the starting point for distinguishing the suction surface and the pressure surface is often not the exact leading edge, but the stagnation point near the leading edge. Since the air flow on the suction surface and the pressure surface has significant differences in flow, roughness evaluation is often performed separately for the suction surface and the pressure surface. In other words, according to the blade roughness evaluation method of the exemplary embodiment of the present disclosure, starting from step S202, taking the data processing of the roughness profile of a single suction surface or a single pressure surface as an example, the evaluation process is described, and it will not be repeated below. For the entire target cross-section, the processes of steps S202 to S204 can be respectively executed for the suction surface and the pressure surface to achieve the evaluation.

[0050] When determining the roughness profile of the target cross-section in step S201, the suction surface and the pressure surface may not be distinguished first, and starting from step S202, the roughness profile of the surface to be evaluated can be selected as needed.

[0051] Optionally, the chordwise spacing between any one of the multiple set points and the leading edge of the target section is less than or equal to a set spacing. Since the most important geometric profile of the blade lies in the section near the leading edge in the chordwise direction, the measurement and evaluation of roughness can also be mainly focused on these sections. That is, by selecting multiple set points in the section less than the set spacing from the leading edge of the target section, the effectiveness of roughness evaluation can be improved, the calculation amount can be reasonably reduced, and the evaluation efficiency can be increased. As an example, the set spacing can be a set ratio of the chord length of the target section, such as 40%. As an example, when determining the set points, the section to be measured can be determined first, and then the set points can be selected within this section. For example, the set points can be selected at equal intervals according to a fixed number, or the set points can be selected according to a fixed spacing. It can also combine simulation or test data to further determine the sub-section with relatively violent airflow flow change within the measured section and increase the set point density in this sub-section. The present disclosure does not limit this.

[0052] In step S203, obtain the cyclic threshold corresponding to the roughness amplitude. Wherein, the cyclic threshold represents the number of cycles experienced by the airflow when flowing along the blade with the roughness amplitude until it reaches the transition state. Specifically, it is the number of cycles experienced by the airflow flowing from the stagnation point along the target section until it reaches the transition state.

[0053] Referring to fatigue analysis, the cyclic threshold corresponding to a type of load cycle represents the number of cycles of this type of load cycle that the component bears when it reaches the design life. The cyclic threshold used in roughness evaluation is similar to this. The difference is that in fatigue analysis, the load mean has an important impact on the fatigue life, while the impact of the roughness mean on the airflow can be basically ignored, and the impact of the roughness amplitude is mainly considered. By obtaining the cyclic threshold corresponding to the roughness amplitude instead of determining the corresponding cyclic threshold for each set of cyclic data, the cyclic data with the same roughness amplitude but different roughness means can be combined and processed together, thereby reducing the calculation amount without affecting the evaluation accuracy. As an example, based on the definition of the cyclic threshold, for the blade with the corresponding roughness amplitude, the number of cycles experienced by the airflow flowing from the stagnation point until it reaches the transition state, that is, the number of roughness cycles that the airflow has passed through, can be determined through numerical simulation or experimental observation as the value of the cyclic threshold.

[0054] In step S204, based on each set of cyclic data corresponding to each of the multiple set points and the corresponding cyclic threshold, determine the transition point of the target section from the multiple set points to evaluate the influence of the roughness of the target section on the aerodynamic performance of the blade.

[0055] As mentioned above, for each set point, multiple groups of cycle data and corresponding cycle thresholds are combined, and the existing fatigue life calculation method in fatigue analysis (such as the calculation formula of the Miner criterion) is used to calculate whether a transition occurs when the airflow flows to the set point. This is analogous to calculating whether a component has just reached its fatigue life after being subjected to a certain variable amplitude load.

[0056] It should be understood that after determining the turning point, aerodynamic performance data such as the curves of lift, drag, and torque coefficient at the target cross section can also be determined through a series of calculations to intuitively reflect the influence of the roughness of the blade at the target cross section on the aerodynamic performance of the blade. The specific calculation method belongs to the existing technology in this field and will not be elaborated here.

[0057] According to the blade roughness evaluation method of a wind turbine generator set of the exemplary embodiment of the present disclosure, a turning point is determined from multiple set points of the blade target cross-section by performing cycle counting processing on the roughness profile of the blade and combining the cycle threshold value corresponding to the roughness amplitude. The turning point can be reasonably determined based on the physical relationship between roughness and transition, which helps to evaluate the impact of roughness on the aerodynamic performance of the blade.

[0058] Next, a blade roughness evaluation method of a wind turbine generator set according to an exemplary embodiment of the present disclosure is further introduced.

[0059] Regarding the determination of the roughness profile and cycle data, as mentioned above, since the multiple sets of cycle data corresponding to each set point describe the roughness cycle of the line segment experienced by the airflow from the stagnation point to the corresponding set point, the roughness profile corresponding to each set point is the roughness profile from the stagnation point to the corresponding set point. The airflow will first flow through the upstream set point and then flow through the downstream set point, which means that the roughness profile corresponding to the upstream set point will be included in the roughness profile corresponding to the downstream set point.

[0060] To determine the multiple sets of cycle data corresponding to each set point, in some embodiments, optionally, step S202 includes: dividing the roughness profile determined in step S201 into multiple segments with multiple set points as boundaries, processing each segment of the roughness profile using a cycle counting method, and obtaining cycle data of each segment of the roughness profile; for each set point among the multiple set points on the target cross section of the target blade, accumulating the cycle data of each segment of the roughness profile upstream of the set point, and obtaining multiple sets of cycle data corresponding to the set point. By performing cycle counting processing on the roughness profile segments and then directly accumulating the cycle data for each set point, the data processing amount of the cycle counting can be reduced, and the calculation load can be reduced.

[0061] In some other embodiments, optionally, step S201 includes: for each set point among a plurality of set points on the target section of the target blade, determining the roughness profile from the stagnation point of the target section to the set point; step S202 includes: processing the roughness profile corresponding to each set point among the plurality of set points using the cycle counting method to obtain multiple sets of cycle data corresponding to the set point. By separately determining the roughness profile from the stagnation point to the current set point for each set point, the roughness profile corresponding to each set point can be accurately restored. At this time, the larger the amount of data of the roughness profile corresponding to the set point further downstream, the more accurate the cycle data obtained can be by performing cycle counting processing on the overall larger amount of data instead of segmenting the processing and then accumulating the processing results, which helps to reduce the calculation error caused by interrupting the data continuity during segmented processing and affecting local cycle counting.

[0062] In the above-mentioned some other embodiments, further optionally, step S201 further includes: obtaining the roughness measurement values of multiple points on the target section; determining the stagnation points corresponding to the target section at multiple angles of attack, and multiple set points located downstream of the stagnation point; the operation of determining the roughness profile from the stagnation point of the target section of the target blade to the set point in step S201 includes: for each stagnation point on the target section of the target blade and its corresponding set point, based on the roughness measurement values of multiple points, determining the roughness profile from the stagnation point to the set point. By first obtaining the roughness measurement values of multiple points as the basic data for subsequent determination of each roughness profile, there is no need to re-acquire data for each roughness profile, which helps to simplify the process. On this basis, as described above, the stagnation point will change with conditions such as the airfoil and the oncoming flow situation. In the oncoming flow situation, mainly the oncoming flow direction will affect the position of the stagnation point. As Figure 3 shown, the angle between the oncoming flow direction and the chord direction is called the angle of attack α, that is, the stagnation point is related to the angle of attack α. By separately determining the stagnation points for multiple angles of attack and determining multiple downstream set points corresponding to the stagnation point from multiple points, and then determining the roughness profiles corresponding to each set point downstream of the stagnation point under each angle of attack, it is possible to separately evaluate the influence of roughness on the aerodynamic performance of the blade for different airflow states (i.e., different oncoming flow directions, different angles of attack), achieving a more comprehensive evaluation.

[0063] Specifically, the roughness measurement values of multiple points are essentially the ordinate values of the roughness profiles corresponding to multiple points. There are mainly two means for measuring the roughness profiles corresponding to multiple points, and the specific method for determining multiple set points downstream of the stagnation point is slightly different accordingly.

[0064] One is to use a standard and calibrated roughness measuring instrument to obtain the roughness profile within the evaluation length of the selected area on the blade surface. The measurement points at this time serve as the multiple points mentioned above. These measurement points can meet the condition of "the chordwise distance from the leading edge of the target section is less than or equal to the set distance" introduced above, so there is no need to perform secondary screening on these points. After determining the stagnation point, taking the stagnation point as the boundary, these multiple points are divided into points belonging to the suction surface and points belonging to the pressure surface, which are respectively used as the set points when evaluating the roughness of the suction surface and the pressure surface. It should be understood that since the airflow divides at the stagnation point, these points are all located downstream of the stagnation point. Determining "multiple set points located downstream of the stagnation point" specifically means determining multiple set points located downstream of the stagnation point on the suction surface, or multiple set points located downstream of the stagnation point on the pressure surface, that is, determining multiple set points on the suction surface based on the stagnation point, or determining multiple set points on the pressure surface based on the stagnation point.

[0065] The other is to use a non-contact measurement device, such as an optical measurement device, to measure the roughness profile along the entire spanwise section. After determining the stagnation point, taking the stagnation point as the boundary, the suction surface and the pressure surface can be distinguished, and then multiple set points are determined from the suction surface or the pressure surface. As described in the previous paragraph, these set points are all located downstream of the stagnation point, and the difference lies in whether they belong to the suction surface or the pressure surface. The specific determination method can refer to the conditions based on the set distance and the relevant introduction in the previous text, which will not be elaborated here.

[0066] Regarding the determination of the transition point, optionally, step S204 includes: for each set point among the multiple set points, statistically process the set ratios corresponding to each group of cyclic data to obtain the set ratio statistical value of the set point, where the set ratio is the ratio of the number of cycles to the cycle threshold; determine the transition point of the target section from the multiple set points according to the set ratio statistical value of each set point among the multiple set points. For a single roughness mean value, the ratio of the number of cycles to the cycle threshold (i.e., the set ratio) reflects the proportion of the number of cycles in the cycle threshold. If the airflow flowing to reach the transition state is regarded as a complete journey, this ratio reflects the completion degree of the airflow journey. Each set point has multiple groups of cyclic data, so there are multiple set ratios. By determining the statistical values of these set ratios, such as the sum value and the weighted sum value, it can reflect the completion of the airflow journey when flowing to the corresponding set point. Then, combined with the set ratio statistical value of each set point, the point where the airflow undergoes transition, that is, the transition point, can be determined from the multiple set points, realizing the reliable determination of the transition point.

[0067] Optionally, the operation of determining the transition point of the target cross-section from multiple set points according to the set ratio statistical value of each set point in step S204 includes: sorting the multiple set points in ascending order of the distance from the stagnation point of the target cross-section, and comparing the set ratio statistical value of each set point with the statistical value threshold one by one; determining the set point corresponding to the first set ratio statistical value greater than or equal to the statistical value threshold as the transition point of the target cross-section. On the one hand, the flow of the air flow is continuous, and the change of the air flow state is also continuous. Therefore, for multiple set points arranged in order of position, the set ratio statistical value should increase gradually. On the other hand, the statistical value threshold represents the set ratio statistical value of the point where the air flow undergoes transition. If the set ratio statistical value of a certain set point is less than the statistical value threshold, it means that the air flow is in a laminar state at this set point; if the set ratio statistical value of a certain set point is equal to the statistical value threshold, it means that the air flow is just in a transition state at this set point; if the set ratio statistical value of a certain set point is greater than the statistical value threshold, it means that the air flow has entered a turbulent state at this set point. By first sorting by position and then determining the first set point whose set ratio statistical value is greater than or equal to the statistical value threshold, it can be considered that the air flow just undergoes transition or has just undergone transition not long ago at this set point, and this set point can be used as the transition point, realizing the efficient determination of the transition point. It should be understood that when the air flow flows along the blade surface, the transition point is theoretically only one point. However, when selecting set points, it is very likely that the transition point is not selected exactly. At this time, the set point that first reaches the turbulent state can be selected from multiple set points as the determined transition point. Of course, if the transition point is just selected, there will be a set point whose set ratio statistical value is equal to the statistical value threshold as the accurate transition point. Therefore, there is a reasonable error in the determined transition point. Of course, for the case where the transition point is not selected when selecting set points, the last point less than the statistical value threshold can also be used as the determined transition point, that is, the set point corresponding to the last set ratio statistical value less than or equal to the statistical value threshold is used as the transition point of the target cross-section, which is also an implementation manner of the present disclosure and falls within the protection scope of the present disclosure.

[0068] It should be noted that, for the suction surface or the pressure surface alone, the distance relationship between multiple set points and the stagnation point in the present disclosure is determined. Therefore, during the evaluation, multiple sets of cycle data corresponding to each set point can be calculated at one time in step S202, and then in step S204, it can be determined one by one whether the sorted multiple set points are transition points. Once a transition point is determined in this way, the subsequent relevant calculations and judgments for other set points will no longer be continued; it is also possible to sort the multiple set points based on the stagnation point before executing step S202 (during the process of determining the set points, the determination of their arrangement order often accompanies), and perform the calculation and judgment operations in steps S202 to S204 for each set point in order, that is, perform cycle counting for each set point one by one and combine the cycle threshold to determine whether the set point is a transition point. Once a transition point is determined in this way, the cycle counting for the subsequent other set points will no longer be performed. These are all implementation manners of the present disclosure and fall within the protection scope of the present disclosure.

[0069] Next, a specific embodiment is combined to introduce the blade roughness evaluation method of the present disclosure.

[0070] In this specific embodiment, the measurement and evaluation of the overall roughness of the target blade are simplified to the measurement and evaluation of the roughness of several spanwise sections. Then, by performing rain flow method processing on the measurement data, a statistical table of the roughness mean value, roughness amplitude, and number of cycles corresponding to different given chordwise positions under different stagnation points (i.e., different angles of attack) is obtained. By comparing with the cycle threshold obtained through theoretical calculation or testing, the influence of the actual roughness on the aerodynamic performance of this spanwise section under different angles of attack can be obtained.

[0071] For any spanwise section, the specific processing steps are as follows:

[0072] 1. Roughness measurement

[0073] Two methods can be adopted to measure the roughness profile of the blade surface: The first is to use a standard and calibrated roughness measuring instrument to obtain the roughness profiles within the evaluation lengths of multiple selected areas on the blade surface, and then based on the measured multiple roughness profiles, obtain the roughness profile of the continuous area on the blade surface. The continuous area is the area for which the roughness profile needs to be obtained, which can be the entire blade surface or a part of the blade surface. Specifically, if the evaluation length is long enough, reaching the centimeter or decimeter level, the targeted continuous area can be divided into multiple continuously distributed sub-areas, and the length of each sub-area is equal to the evaluation length. Thus, by measuring and splicing the roughness profiles within multiple continuously distributed evaluation lengths, the roughness profile of the entire continuous area can be obtained. If the evaluation length is short, only at the millimeter level, it is not convenient to adopt the continuous measurement method. At this time, multiple selected areas spaced from each other can be selected from the targeted continuous area at different positions along the chord direction, and the roughness profiles within the evaluation lengths of each selected area are measured respectively. Then, random interpolation is performed using the roughness profiles measured for two adjacent selected areas as the roughness profile of the interval area between these two selected areas. Furthermore, the roughness profiles of these multiple selected areas and the interval areas are spliced in sequence to obtain the roughness profile of the entire continuous area. For the latter, the selected area can be, for example, at the point with a specified spacing (not the set spacing introduced above) from the leading edge of the blade along the chord direction, that is, the roughness profile within the evaluation length is measured at this point. The specified spacing includes, for example, 5% chord length, 10% chord length, 20% chord length, 30% chord length. At this time, the roughness profiles within the evaluation lengths can be measured at these four points respectively. Since the evaluation length is only at the millimeter level, it can be approximately considered that the evaluation length is located at this point. Precisely speaking, this point can also be used as the starting point, midpoint or end point of the evaluation length to clarify the measurement position. The second is to use a non-contact measurement device, such as optical measurement, to measure the roughness profile along the entire spanwise section.

[0074] Since the current length of the blade can exceed 100 meters, some representative characteristic cross-sections can be selected to replace the entire blade, and the spanwise intervals of these characteristic cross-sections can be set to 1 meter or 2 meters. In addition, since the most important geometric profile of the blade lies in the position area of 40% chord length near the leading edge in the chord direction, the measurement of roughness can also be mainly concentrated in these places.

[0075] By measuring a given number of points, which can be selected as 9, 16, etc., along the chord direction within 40% chord length near the leading edge for different spanwise cross-sections, the roughness profile of the measured spanwise cross-section can be obtained. Since in the actual process, the blade airfoil is usually interpolated from a series of given standard airfoils, it is considered that the test can be further simplified by only measuring the roughness of the standard airfoil cross-section.

[0076] 2. Roughness data processing

[0077] For the entire blade, roughness profiles can be obtained by measuring different spanwise sections. Then, several set points are selected at different chordwise positions, and the roughness from the stagnation point to different set points is calculated. Among them, the rainflow counting method is used to process the measured roughness data, and the equivalent roughness mean value, roughness amplitude, and number of cycles at the measurement points are obtained. (The reason for proposing the equivalent is that a series of calibrations need to be carried out first when using the rainflow counting method, which belongs to the existing mature technology and will not be elaborated here). Therefore, after processing, the roughness mean value, roughness amplitude, and number of cycles of different set points at different stagnation points (i.e., corresponding to different angles of attack) on a certain spanwise section (which may be the spanwise section of the actual blade or the standard airfoil section) will actually be obtained.

[0078] 3. Evaluating the influence of roughness

[0079] The influence of roughness is mainly achieved by triggering flow transition in advance. Therefore, evaluating the influence of roughness is to find the specific position where the airflow transition occurs. By using computational fluid dynamics software or experiments, the boundary of the flow from laminar to turbulent can be obtained for the measured spanwise section under different roughness mean values, roughness amplitudes, and their number of cycles, that is, for any roughness mean value, when its roughness amplitude is a certain number, the number of cycles required for the flow to transition from laminar to turbulent. Therefore, after obtaining a statistical table in the previous step, the results can be divided by the cycle threshold Ni corresponding to the roughness amplitude (i.e., the theoretical number of cycles Ni for the blade with this roughness amplitude to trigger transition) and then summed up. Its calculation formula can be expressed as:

[0080]

[0081] Among them, σ represents the cumulative influence of the roughness amplitude. When it is greater than or equal to 1, it indicates that the flow changes from laminar to turbulent. m is the number of different roughness amplitudes.

[0082] For different positions along the chord, the points where σ is greater than or equal to 1 for the first time under different angles of attack are statistically obtained as the transition points, that is, it is considered that the airflow transitions at these points.

[0083] Figure 4 is a block diagram showing a blade roughness evaluation device of a wind turbine according to an embodiment of the present disclosure. Referring to Figure 4 , the blade roughness evaluation device 400 of the wind turbine includes a profile determination unit 401, a cycle counting unit 402, a threshold acquisition unit 403, and a transition determination unit 404.

[0084] The profile determination unit 401 can determine the roughness profile of the target cross-section of the target blade, where the target cross-section is a cross-section perpendicular to the spanwise direction of the blade.

[0085] Optionally, the target blade is a blade of a wind turbine that has completed design; or the target blade is a standard airfoil blade with a unit length.

[0086] The cycle counting unit 402 can process the roughness profile using the cycle counting method to obtain multiple sets of cycle data corresponding to each set point among multiple set points on the target cross-section, where each set of cycle data includes a roughness amplitude and a number of cycles.

[0087] Optionally, the chordwise spacing between any set point among the multiple set points and the leading edge of the target cross-section is less than or equal to a set spacing.

[0088] The threshold acquisition unit 403 can acquire a cycle threshold corresponding to the roughness amplitude, where the cycle threshold represents the number of cycles experienced to reach the transition state when the airflow flows along the blade with the roughness amplitude.

[0089] The transition determination unit 404 can determine the transition point of the target cross-section from among the multiple set points based on the multiple sets of cycle data corresponding to each set point among the multiple set points and the corresponding cycle threshold, so as to evaluate the influence of the roughness of the target cross-section on the aerodynamic performance of the blade.

[0090] Optionally, the profile determination unit 401 can also, for each set point among the multiple set points on the target cross-section of the target blade, determine the roughness profile from the stagnation point of the target cross-section to the set point; the cycle counting unit 402 can also process the roughness profile corresponding to each set point among the multiple set points using the cycle counting method to obtain multiple sets of cycle data corresponding to the set point.

[0091] Optionally, the profile determination unit 401 can also: acquire the roughness measurement values of multiple points on the target cross-section; determine the stagnation points corresponding to the target cross-section at multiple angles of attack, and multiple set points located downstream of the stagnation point; for each stagnation point and its corresponding set point on the target cross-section of the target blade, based on the roughness measurement values of the multiple points, determine the roughness profile from the stagnation point to the set point.

[0092] Optionally, the transition determination unit 404 can also: for each set point among the multiple set points, perform statistical processing on the set ratios corresponding to each set of cycle data to obtain the set ratio statistical value of the set point, where the set ratio is the ratio of the number of cycles to the cycle threshold; determine the transition point of the target cross-section from among the multiple set points according to the set ratio statistical value of each set point among the multiple set points.

[0093] Optionally, the transition determination unit 404 may further: sort a plurality of set points in ascending order of the distance from the stagnation point of the target cross-section, and compare the set ratio statistical value of each set point with the statistical value threshold one by one; determine the set point corresponding to the first set ratio statistical value greater than or equal to the statistical value threshold as the transition point of the target cross-section.

[0094] Regarding the device in the above embodiments, the specific manner in which each unit performs operations has been described in detail in the embodiments related to the method, and will not be elaborated herein.

[0095] The method for evaluating the blade roughness of a wind turbine according to an embodiment of the present disclosure can be written as a computer program and stored on a computer-readable storage medium. When the instructions corresponding to the computer program are executed by a processor, the method for evaluating the blade roughness of a wind turbine as described above can be implemented. Examples of computer-readable storage media include: read-only memory (ROM), random access programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, non-volatile memory, CD-ROM, CD-R, CD+R, CD-RW, CD+RW, DVD-ROM, DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM, BD-ROM, BD-R, BD-R LTH, BD-RE, Blu-ray or optical disc memory, hard disk drive (HDD), solid state drive (SSD), cartridge memory (such as, multimedia card, secure digital (SD) card or extreme digital (XD) card), magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid state disk, and any other device configured to store the computer program and any associated data, data files, and data structures in a non-transitory manner and provide the computer program and any associated data, data files, and data structures to a processor or computer such that the processor or computer can execute the computer program. In one example, the computer program and any associated data, data files, and data structures are distributed across a networked computer system such that the computer program and any associated data, data files, and data structures are stored, accessed, and executed in a distributed manner by one or more processors or computers.

[0096] Figure 5 is a block diagram showing a computer device according to an embodiment of the present disclosure.

[0097] Refer to Figure 5, the computer device 500 includes at least one memory 501 and at least one processor 502. A set of computer-executable instructions is stored in the at least one memory 501. When the set of computer-executable instructions is executed by the at least one processor 502, a method for evaluating the blade roughness of a wind turbine according to an exemplary embodiment of the present disclosure is performed.

[0098] As an example, the computer device 500 can be a PC computer, a tablet device, a personal digital assistant, a smart phone, or other devices capable of executing the above instruction set. Here, the computer device 500 does not have to be a single electronic device, and can also be a collection of any devices or circuits capable of executing the above instructions (or instruction sets) individually or jointly. The computer device 500 can also be a part of an integrated control system or system manager, or can be configured as a portable electronic device that is interconnected with a local or remote (e.g., via wireless transmission) interface.

[0099] In the computer device 500, the processor 502 can include a central processing unit (CPU), a graphics processing unit (GPU), a programmable logic device, a dedicated processor system, a microcontroller, or a microprocessor. As an example and not a limitation, the processor can also include an analog processor, a digital processor, a microprocessor, a multi-core processor, a processor array, a network processor, etc.

[0100] The processor 502 can run the instructions or code stored in the memory 501. Among them, the memory 501 can also store data. The instructions and data can also be sent and received through the network via a network interface device, where the network interface device can adopt any known transmission protocol.

[0101] The memory 501 can be integrated with the processor 502. For example, RAM or flash memory is arranged within an integrated circuit microprocessor, etc. In addition, the memory 501 can include independent devices, such as an external disk drive, a storage array, or other storage devices that can be used by any database system. The memory 501 and the processor 502 can be operatively coupled, or can communicate with each other, for example, through an I / O port, a network connection, etc., so that the processor 502 can read the files stored in the memory.

[0102] In addition, the computer device 500 can also include a video display (such as a liquid crystal display) and a user interaction interface (such as a keyboard, a mouse, a touch input device, etc.). All components of the computer device 500 can be connected to each other via a bus and / or a network.

[0103] The present disclosure provides a method, an apparatus, and a storage medium for evaluating the roughness of a blade of a wind turbine. By performing cyclic counting processing on the roughness profile of the blade and combining the cyclic threshold corresponding to the roughness amplitude, the transition points are determined from multiple set points of the target section of the blade. Based on the physical relationship between roughness and transition, the transition points can be reasonably determined, which helps to evaluate the influence of roughness on the aerodynamic performance of the blade.

[0104] The specific embodiments of the present disclosure have been described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that these embodiments can be modified and varied without departing from the principles and spirit of the present disclosure defined by the claims and their equivalents, and such modifications and variations should also be within the protection scope of the claims of the present disclosure.

Claims

1. A method for evaluating the blade roughness of a wind turbine generator, characterized in that, The blade roughness evaluation method includes: Determine the roughness profile of the target section of the target blade, where the target section is a section perpendicular to the spanwise direction of the blade; Process the roughness profile using the cycle counting method to obtain multiple sets of cycle data corresponding to each set point among the multiple set points on the target section, where each set of cycle data includes a roughness amplitude and a cycle number; Obtain the cycle threshold corresponding to the roughness amplitude, where the cycle threshold represents the number of cycles experienced to reach the transition state when the air flow flows along the blade with the roughness amplitude; Determine the transition point of the target section from the multiple set points according to the multiple sets of cycle data corresponding to each set point among the multiple set points and the corresponding cycle threshold, so as to evaluate the influence of the roughness of the target section on the aerodynamic performance of the blade.

2. The blade roughness evaluation method according to claim 1, wherein: The determination of the roughness profile of the target section of the target blade includes: For each set point among the multiple set points on the target section of the target blade, determine the roughness profile from the stagnation point of the target section to the set point; The process of using the cycle counting method to process the roughness profile to obtain multiple sets of cycle data corresponding to each set point among the multiple set points on the target section includes: Process the roughness profile corresponding to each set point among the multiple set points using the cycle counting method to obtain multiple sets of cycle data corresponding to the set point.

3. The blade roughness evaluation method according to claim 2, wherein The determination of the roughness profile of the target section of the target blade further includes: Obtain the roughness measurement values of multiple points on the target section; Determine the stagnation points corresponding to the target section at multiple angles of attack respectively, and multiple set points located downstream of the stagnation point; The step of, for each set point among the multiple set points on the target section of the target blade, determining the roughness profile from the stagnation point of the target section to the set point includes: For each stagnation point on the target section of the target blade and its corresponding set point, based on the roughness measurement values of the multiple points, determine the roughness profile from the stagnation point to the set point.

4. The blade roughness evaluation method according to claim 1, characterized in that, The step of determining the transition point of the target section from the multiple set points according to the multiple sets of cycle data corresponding to each set point among the multiple set points and the corresponding cycle threshold includes: For each set point among the multiple set points, perform statistical processing on the set ratios corresponding to each set of cycle data to obtain the set ratio statistical value of the set point, where the set ratio is the ratio of the cycle number to the cycle threshold; Determine the transition point of the target section from the multiple set points according to the set ratio statistical value of each set point among the multiple set points.

5. The blade roughness evaluation method according to claim 4, wherein The step of determining the transition point of the target section from the multiple set points according to the set ratio statistical value of each set point among the multiple set points includes: Sort the multiple set points in ascending order of the distance from the stagnation point of the target section, and compare the set ratio statistical value of each set point with the statistical value threshold one by one; Determine the set point corresponding to the set ratio statistic value that is the first to be greater than or equal to the threshold of the statistic value as the transition point of the target section.

6. The blade roughness evaluation method according to any one of claims 1 to 5, characterized in that, The chordwise distance between any set point among the multiple set points and the leading edge of the target section is less than or equal to a set distance.

7. The blade roughness evaluation method according to any one of claims 1 to 5, characterized in that the target blade is a wind turbine blade that has completed design; or the target blade is a standard airfoil blade with a unit length.

8. A blade roughness evaluation device, characterized in that, The blade roughness evaluation device includes: a profile determination unit configured to determine the roughness profile of a target section of a target blade, wherein the target section is a section perpendicular to the spanwise direction of the blade; a cycle counting unit configured to process the roughness profile using a cycle counting method to obtain multiple sets of cycle data corresponding to each set point among the multiple set points on the target section, wherein each set of cycle data includes a roughness amplitude and a number of cycles; a threshold acquisition unit configured to acquire a cycle threshold corresponding to the roughness amplitude, wherein the cycle threshold represents the number of cycles experienced to reach a transition state when the airflow flows along the blade with the roughness amplitude; a transition determination unit configured to determine the transition point of the target section from the multiple set points according to the multiple sets of cycle data corresponding to each set point among the multiple set points and the corresponding cycle threshold, so as to evaluate the influence of the roughness of the target section on the aerodynamic performance of the blade.

9. A computer-readable storage medium, characterized in that, When the instructions in the computer-readable storage medium are run by at least one processor, the at least one processor is caused to execute the blade roughness evaluation method of the wind turbine according to any one of claims 1 to 7.

10. A computer device, characterized in that, including: at least one processor; at least one memory storing computer-executable instructions, wherein, when the computer-executable instructions are run by the at least one processor, the at least one processor is caused to execute the blade roughness evaluation method of the wind turbine according to any one of claims 1 to 7.

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