Calculation method for vortex-induced resonance area of fan blade and anti-vortex-induced device

Abstract

The invention provides a calculation method for a vortex-induced resonance area of a fan blade and an anti-vortex-induced device, and relates to the technical field of wind power equipment. According to the method, the inherent frequency of the fan blade is firstly obtained, then the fan blade is segmented to obtain a plurality of blade sections, and then the vortex shedding frequency of the section of each blade area under different wind speeds or different working conditions is calculated; and finally, the vortex shedding frequency of the section of each blade section under different wind speeds or different working conditions is compared with the inherent frequency, so that the vortex-induced vibration area of the fan blade is determined. According to the technical scheme, the main energy injection area, namely the vortex-induced vibration area, where the vortex-induced vibration phenomenon occurs on the fan blade is determined, the vortex-induced vibration device is installed in the vortex-induced vibration area, the effectiveness of vortex-induced measures is improved, meanwhile, invalid arrangement of the vortex-induced vibration device can be reduced, and cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power equipment, and in particular to a method for calculating the vortex-induced resonance area of ​​a wind turbine blade and an anti-vortex-induced resonance device. Background Art

[0002] With the development of wind power generation technology and equipment, users' requirements for the efficiency, safety and service life of wind turbines will gradually increase. The blades of wind turbines will produce periodic vibrations due to fluid dynamic effects at specific wind speeds. This vibration is usually caused by the formation of vortices in the flowing air by the blades. When the frequency of vortex shedding is close to the natural frequency of the blades, resonance will occur, causing the blades to vibrate greatly. In the prior art, in order to suppress this vibration, an anti-vortex excitation device will be set on the blades of the wind turbine generator. If the anti-vortex excitation device is accurately installed in the vortex resonance area, the anti-vortex excitation effect will be achieved. If the installation position of the anti-vortex excitation device is inaccurate, an invalid arrangement will be formed and the anti-vortex excitation effect will not be achieved. Therefore, the installation position of the anti-vortex excitation device is particularly important, and it is urgent to design a method that can accurately find the vortex resonance area to effectively arrange the anti-vortex excitation device. Summary of the invention

[0003] One object of the present invention is to provide a method for calculating the vortex-induced resonance area of ​​a fan blade, so as to solve the technical problem in the prior art that the ineffective arrangement of anti-vortex-induced resonance devices affects the anti-vortex-induced resonance effect.

[0004] A further object of the present invention is to enable a more accurate calculation of the vortex induced vibration area.

[0005] Another object of the present invention is to provide an anti-vortex excitation device to improve the anti-vortex excitation effect.

[0006] In particular, the present invention provides a method for calculating the vortex-induced resonance area of ​​a fan blade, comprising the following steps:

[0007] Obtain the natural frequency of the fan blades;

[0008] Segmenting the fan blade to obtain a plurality of blade sections;

[0009] Calculating the vortex shedding frequency of each cross section of the blade section at different wind speeds or different working conditions;

[0010] The vortex shedding frequency and the natural frequency of the cross section of each blade section under different wind speeds or different working conditions are compared to determine the vortex-induced vibration area of ​​the wind turbine blade.

[0011] Optionally, the step of respectively calculating the vortex shedding frequency of the cross section of each blade section at different wind speeds or under different operating conditions specifically includes:

[0012] Obtaining wind speed information and a cross-sectional airfoil chord length of each blade section;

[0013] The vortex shedding frequency of the cross section of each blade section at different wind speeds is calculated respectively according to the wind speed information and the cross-sectional airfoil chord length of each blade section.

[0014] Optionally, the vortex shedding frequency of the cross section of each blade section at different wind speeds is calculated according to the following formula:

[0015] Sr=fD / U Formula (1);

[0016] Wherein, Sr represents the Strouhal number, f represents the vortex shedding frequency, D represents the cross-sectional airfoil chord length of the blade section, and U represents the wind speed.

[0017] Optionally, the step of respectively calculating the vortex shedding frequency of the cross section of each blade section at different wind speeds or under different operating conditions specifically includes:

[0018] Simulating the cross section of each blade section at different attack angles and different wind speeds to obtain a modified Strouhal number of the cross section of each blade section under different working conditions, and obtaining the distance between free streamlines at the wake formed by the airflow passing through the cross section of each blade section and the free flow velocity at the flow separation point of the cross section of each blade section;

[0019] The vortex shedding frequency of the cross section of each blade section under different working conditions is calculated based on the modified Strouhal number, the distance between the free streamlines at the wake formed by the airflow flowing through the cross section of each blade section, and the free flow velocity at the cross-sectional flow separation point of each blade section.

[0020] Optionally, the vortex shedding frequency of the cross section of each blade section under different working conditions is calculated according to the following formula:

[0021] Universal Sr=fD' / Us formula (2);

[0022] Wherein, Universal Sr represents the modified Strouhal number, f represents the vortex shedding frequency, Us represents the free flow velocity at the cross-sectional flow separation point of the blade section, and D' represents the distance between free streamlines at the wake formed by the airflow flowing through the cross-sectional area of ​​the blade section.

[0023] Optionally, the step of respectively calculating the vortex shedding frequency of the cross section of each blade section at different wind speeds or under different operating conditions specifically includes:

[0024] Build a target model;

[0025] The cross section of each blade section is input into the target model to obtain the vortex shedding frequency of the cross section of each blade section under different working conditions.

[0026] Optionally, the step of inputting the cross section of each blade section into the target model to obtain the vortex shedding frequency of the cross section of each blade section under different working conditions specifically includes:

[0027] Inputting the geometric model of the wind turbine blade into the target model to determine the calculation domain and boundary conditions;

[0028] Performing grid division and parameter setting on the computational domain;

[0029] Using dynamic mesh technology and compiling UDF program to realize the movement of the fan blades in the flow field;

[0030] Performing vortex-induced vibration simulation on the fan blades at different wind speeds and different attack angles;

[0031] The simulation results are extracted and analyzed by calculation to obtain the vortex shedding frequency of each cross section of the blade section under different working conditions.

[0032] Optionally, the step of comparing the vortex shedding frequency and the natural frequency of the cross section of each blade segment at different wind speeds or under different operating conditions to determine the vortex-induced vibration area of ​​the wind turbine blade further includes:

[0033] Obtaining the vibration mode amplitude, the corresponding frequency and the corresponding wind speed corresponding to the vortex-induced vibration area;

[0034] The final vortex-induced vibration region of the fan blade is determined according to the vibration mode amplitude, the corresponding frequency and the corresponding wind speed corresponding to the vortex-induced vibration region.

[0035] Optionally, the natural frequency of the fan blade includes a first-order natural frequency and a second-order natural frequency.

[0036] In particular, the present invention also provides a computer device, comprising a memory, a processor, and a machine executable program stored in the memory and running on the processor, and the processor implements the above-mentioned computing method when executing the machine executable program.

[0037] In particular, the present invention further provides an anti-vortex excitation device for a fan blade, which is arranged in a vortex-induced vibration region of the fan blade, and the anti-vortex excitation device comprises:

[0038] At least one group of inclined spoiler blocks, each group of the inclined spoiler blocks includes at least a first inclined spoiler block arranged at a leading edge of the fan blade and at least a second inclined spoiler block arranged at a trailing edge of the fan blade, wherein the first inclined spoiler block and the second inclined spoiler block both extend obliquely from the fan blade; and

[0039] At least one group of spanwise spoiler strip groups, each group of the spanwise spoiler strip groups includes at least one first spanwise spoiler strip arranged at the leading edge of the fan blade and at least one second spanwise spoiler strip arranged at the trailing edge of the fan blade, the first spanwise spoiler strip and the second spanwise spoiler strip are both arranged along the extension direction of the fan blade.

[0040] Optionally, there are multiple groups of inclined spoiler block groups, and there are multiple groups of spanwise spoiler strip groups, and the multiple groups of inclined spoiler block groups and the multiple groups of spanwise spoiler strip groups are staggered along the extension direction of the fan blade.

[0041] Optionally, in each group of the inclined spoiler blocks, the first inclined spoiler blocks and the second inclined spoiler blocks are both inclined toward the tip direction of the fan blade or are both inclined toward the root direction of the fan blade.

[0042] Optionally, the inclination directions of the first inclined spoiler blocks in the plurality of groups of inclined spoiler blocks are consistent, and the inclination directions of the second inclined spoiler blocks are consistent.

[0043] Optionally, in two adjacent groups of the inclined spoiler blocks, the inclination directions of the first inclined spoiler blocks are opposite, and the inclination directions of the second inclined spoiler blocks are opposite.

[0044] Optionally, in each group of the inclined spoiler blocks, the first inclined spoiler block is arranged on the pressure side or the suction side of the fan blade, and the second inclined spoiler block is arranged on the side opposite to the first inclined spoiler block.

[0045] Optionally, the first inclined spoiler blocks in the plurality of groups of inclined spoiler blocks are all arranged on the pressure side or the suction side of the fan blade.

[0046] Optionally, in each group of the spanwise spoiler strips, the first spanwise spoiler strips are arranged on the pressure side or the suction side of the wind turbine blade, and the second spanwise spoiler strips are arranged on the side opposite to the first spanwise spoiler strips.

[0047] Optionally, two groups of the first spanwise spoiler strips in two adjacent groups of the spanwise spoiler strips are respectively arranged on the pressure side and the suction side of the fan blade.

[0048] Optionally, in each group of the spanwise spoiler strips, the first spanwise spoiler strips and the second spanwise spoiler strips both extend out of the fan blades.

[0049] The present invention first obtains the natural frequency of the fan blades, then segments the fan blades to obtain multiple blade sections, then calculates the vortex shedding frequency of the cross section of each blade area at different wind speeds or under different working conditions, and finally compares the vortex shedding frequency and the natural frequency of the cross section of each blade section at different wind speeds or under different working conditions to determine the vortex-induced vibration area of ​​the fan blades. The above technical solution clarifies the main energy injection area where the vortex-induced vibration phenomenon of the fan blades occurs, that is, the vortex-induced vibration area, so that an anti-vortex-induced vibration device is installed in the vortex-induced vibration area, thereby improving the effectiveness of the anti-vortex-induced vibration measures, while reducing the ineffective arrangement of the anti-vortex-induced vibration device and saving costs.

[0050] Furthermore, the present invention first simulates the cross section of each blade section at different attack angles and different wind speeds to obtain the modified Strouhal number of the cross section of each blade section under different working conditions, and obtains the distance between free streamlines at the wake formed by the airflow flowing through the cross section of each blade section and the free flow velocity at the flow separation point of the cross section of each blade section, and then calculates the vortex shedding frequency of the cross section of each blade section under different working conditions according to the modified Strouhal number, the distance between free streamlines at the wake formed by the airflow flowing through the cross section of each blade section, and the free flow velocity at the flow separation point of the cross section of each blade section. The above technical scheme fully considers the cross-sectional shape of different blade sections and its influence on the Strouhal number at different attack angles and wind speeds, and with the help of two-dimensional numerical simulation, the cross-sectional shape of different blade sections is subjected to two-dimensional numerical simulation calculation at different attack angles and different wind speeds to obtain the modified Strouhal number under different working conditions, so that the vortex shedding frequency can be calculated more accurately to more accurately determine the vortex-induced vibration area.

[0051] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0053] Figure 1 is a schematic flow chart of a method for calculating a vortex-induced resonance area of ​​a fan blade according to an embodiment of the present invention;

[0054] Figure 2 is a schematic flow chart of a method for calculating a vortex-induced resonance area of ​​a fan blade according to another embodiment of the present invention;

[0055] Figure 3is a schematic flow chart of a method for calculating a vortex-induced resonance area of ​​a fan blade according to another embodiment of the present invention;

[0056] Figure 4 is a schematic flow chart of a method for calculating a vortex-induced resonance area of ​​a fan blade according to another embodiment of the present invention;

[0057] Figure 5 is a schematic flow chart of a method for calculating a vortex-induced resonance area of ​​a fan blade according to another embodiment of the present invention;

[0058] Figure 6 is a schematic diagram of a vortex-induced resonance region for exciting various-order vortex-induced vibration phenomena of a fan blade according to an embodiment of the present invention;

[0059] Figure 7 is a schematic diagram of a final vortex-induced resonance region for exciting various order vortex-induced vibration phenomena of a fan blade according to an embodiment of the present invention;

[0060] Figure 8 is a schematic block diagram of a computer device according to an embodiment of the present invention;

[0061] Fig. 9 is a schematic structural diagram of an anti-vortex-induced vibration device installed in a vortex-induced vibration region of a fan blade according to an embodiment of the present invention;

[0062] Fig.10 yes Fig. 9 A schematic enlarged view of part A;

[0063] Fig.11 is a schematic structural diagram of an anti-vortex excitation device according to an embodiment of the present invention;

[0064] Fig.12 is a schematic structural diagram of an anti-vortex excitation device according to another embodiment of the present invention;

[0065] Fig.13 is a schematic structural diagram of an anti-vortex excitation device according to another embodiment of the present invention;

[0066] Fig.14 It is a schematic structural diagram of an anti-vortex excitation device according to another embodiment of the present invention.

[0067] Reference numerals:

[0068] 100-computer device, 110-processor, 120-memory, 130-machine executable program, 200-fan blade, 300-anti-vortex excitation device, 310-inclined spoiler block group, 320-spanwise spoiler strip group, 311-first inclined spoiler block, 312-second inclined spoiler block, 321-first spanwise spoiler strip, 322-second spanwise spoiler strip. DETAILED DESCRIPTION

[0069] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0070] In the description of this embodiment, it should be understood that the terms "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0071] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features, that is, include one or more of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. When a feature "includes or contains" one or some of the features it covers, unless otherwise specifically described, this indicates that other features are not excluded and may further include other features.

[0072] Unless otherwise clearly defined and limited, the terms "connection", "installation" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. A person skilled in the art should be able to understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0073] Unless otherwise defined, all terms (including technical terms and scientific terms) used in the description of this embodiment have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0074] Figure 1 FIG. 1 is a schematic flow chart of a method for calculating the vortex-induced resonance area of ​​a fan blade according to an embodiment of the present invention. Figure 1 As shown, in one embodiment, the method for calculating the vortex-induced resonance area of ​​a fan blade includes the following steps:

[0075] Step S100, obtaining the natural frequency of the fan blade;

[0076] Step S200, segmenting the fan blade to obtain a plurality of blade sections;

[0077] Step S300, respectively calculating the vortex shedding frequency of each blade section cross section under different wind speeds or different working conditions;

[0078] Step S400, comparing the vortex shedding frequency and the natural frequency of the cross section of each blade section at different wind speeds or under different working conditions to determine the vortex-induced vibration area of ​​the wind turbine blade.

[0079] This embodiment clarifies the main energy injection area where vortex-induced vibration occurs in the fan blades, namely the vortex-induced vibration area, and installs an anti-vortex-induced vibration device in the vortex-induced vibration area, thereby improving the effectiveness of the anti-vortex-induced vibration measures. At the same time, it can reduce the ineffective arrangement of the anti-vortex-induced vibration device and save costs.

[0080] In step S100, the natural frequency of the fan blade includes a first-order natural frequency and a second-order natural frequency. When the natural frequency of the fan blade is obtained, the vibration mode of the fan blade can be obtained. It can be understood that the vortex shedding frequency finally calculated in this embodiment is to be compared with the first-order natural frequency and the second-order natural frequency respectively, and the vortex-induced vibration area under different natural frequencies can be determined.

[0081] In step S200, the fan blades may be segmented at equal intervals. In other embodiments, the fan blades may be segmented according to other segmentation rules.

[0082] Figure 2 FIG. 1 is a schematic flow chart of a method for calculating the vortex-induced resonance area of ​​a fan blade according to another embodiment of the present invention. Figure 2 As shown, in some embodiments, step S300 specifically includes:

[0083] Step S310, obtaining wind speed information and the cross-sectional airfoil chord length of each blade section;

[0084] Step S320 , calculating the vortex shedding frequency of the cross section of each blade section at different wind speeds according to the wind speed information and the cross-sectional airfoil chord length of each blade section.

[0085] This embodiment is equivalent to using the classical definition method to calculate the vortex shedding frequency. When the fluid flows through the structure immersed therein, flow separation occurs and a series of regularly arranged vortices are generated behind the structure. Specifically, the vortex shedding frequency of the cross section of each blade section at different wind speeds is calculated according to the following formula:

[0086] Sr=fD / U Formula (1);

[0087] Among them, Sr represents the Strouhal number, f represents the vortex shedding frequency, D represents the cross-sectional airfoil chord length of the blade section, and U represents the wind speed.

[0088] Here, the Strouhal number is a dimensionless parameter, which is related to the shape of the structural section and the Reynolds number. Here, we simply consider the Sr of the circular section and regard Sr as a constant within the current Reynolds number range. The wind speed is specifically the average wind speed of the incoming flow. Since the Sr of the fan blades is simplified, after using this method to calculate the vortex-induced vibration area, it is necessary to safely amplify the vortex-induced vibration area. Formula (1) is equivalent to the first method for calculating the vortex-induced vibration area.

[0089] Figure 3 FIG. 1 is a schematic flow chart of a method for calculating the vortex-induced resonance area of ​​a fan blade according to another embodiment of the present invention. Figure 3 As shown, in some embodiments, step S300 specifically includes:

[0090] Step S330, simulating the cross section of each blade section at different attack angles and different wind speeds to obtain a modified Strouhal number of the cross section of each blade section under different working conditions, and obtaining the distance between free streamlines at the wake formed by the airflow passing through the cross section of each blade section and the free flow velocity at the flow separation point of the cross section of each blade section;

[0091] Step S340, calculating the vortex shedding frequency of each blade section under different working conditions according to the corrected Strouhal number, the distance between free streamlines at the wake formed by the airflow flowing through the cross section of each blade section, and the free flow velocity at the flow separation point of the cross section of each blade section.

[0092] Specifically, the vortex shedding frequency of each blade section under different working conditions is calculated according to the following formula:

[0093] Universal Sr=fD' / Us formula (2);

[0094] Among them, Universal Sr represents the modified Strouhal number, f represents the vortex shedding frequency, Us represents the free flow velocity at the flow separation point of the blade section, and D' represents the distance between the free streamlines at the wake formed by the airflow flowing through the cross section of the blade section.

[0095] In the calculation of the above formula (1), the cross-sectional shapes of different blade sections and their influence on the Strouhal number at different angles of attack and wind speeds are ignored. However, this embodiment fully considers the cross-sectional shapes of different blade sections and their influence on the Strouhal number at different angles of attack and wind speeds. With the help of two-dimensional numerical simulation, the cross-sectional shapes of different blade sections are subjected to two-dimensional numerical simulation calculations at different angles of attack and different wind speeds to obtain the corrected Strouhal number under different working conditions, so that the vortex shedding frequency can be calculated more accurately to more accurately determine the vortex-induced vibration area. Here, this embodiment is equivalent to adopting a semi-theoretical and semi-empirical mathematical model correction method, and formula (2) is equivalent to the second method for calculating the vortex-induced vibration area.

[0096] Figure 4 FIG. 1 is a schematic flow chart of a method for calculating the vortex-induced resonance area of ​​a fan blade according to another embodiment of the present invention. Figure 4 As shown, in some embodiments, the step of respectively calculating the vortex shedding frequency of the cross section of each blade section under different wind speeds or different working conditions, step S300 specifically includes:

[0097] Step S350, constructing a target model;

[0098] Step S360, inputting the cross section of each blade section into the target model to obtain the vortex shedding frequency of the cross section of each blade section under different working conditions.

[0099] Figure 5 FIG. 1 is a schematic flow chart of a method for calculating the vortex-induced resonance area of ​​a fan blade according to another embodiment of the present invention. Figure 5 As shown, step S360 specifically includes:

[0100] Step S361, inputting the geometric model of the wind turbine blade into the target model to determine the calculation domain and boundary conditions;

[0101] Step S362, meshing the computational domain and setting parameters;

[0102] Step S363, using dynamic mesh technology and compiling UDF program to realize the movement of fan blades in the flow field;

[0103] Step S364, performing vortex-induced vibration simulation on the fan blades at different wind speeds and different attack angles;

[0104] Step S365, extracting the simulation results and performing calculation analysis to obtain the vortex shedding frequency of the cross section of each blade section under different working conditions.

[0105] In the calculation process of formula (2), the three-dimensional effect of the wake vortex after the airflow passes through the fan blades is ignored. However, this embodiment takes into account the three-dimensional effect of the wake vortex after the airflow passes through the fan blades. By calculating the vortex shedding frequency through a three-dimensional model, a more accurate vortex shedding frequency can be obtained. This calculation method is equivalent to the third method for calculating the vortex-induced vibration area.

[0106] Figure 6 1 is a schematic diagram of a vortex-induced resonance region for exciting various order vortex-induced vibration phenomena of a fan blade according to an embodiment of the present invention. Figure 6 As shown, in step S400, by comparing the vortex shedding frequency with the natural frequency, the cross-sectional areas of the vortex shedding frequency near the natural frequencies of each order of the fan blades under different wind speeds or different operating conditions are clarified. These cross-sectional areas are the vortex-induced vibration areas that excite the vortex-induced vibration phenomena of each order of the fan blades, that is, the key areas.

[0107] Figure 7 1 is a schematic diagram of the final vortex-induced resonance region for exciting various order vortex-induced vibration phenomena of a fan blade according to an embodiment of the present invention. Figure 7 As shown, in some embodiments, after step S400, the following steps are further included:

[0108] Step 1: Obtain the vibration mode amplitude, frequency and wind speed corresponding to the vortex-induced vibration area;

[0109] Step 2: Determine the final vortex-induced vibration area of ​​the wind turbine blade according to the vibration mode amplitude, the corresponding frequency and the corresponding wind speed corresponding to the vortex-induced vibration area.

[0110] In this embodiment, when calculating the vortex-induced vibration area of ​​each order, the relative energy contribution of the vortex-induced vibration area to the fan blade is related to the vibration mode amplitude, the corresponding frequency and the corresponding wind speed corresponding to the vortex-induced vibration area. By comprehensively considering the above parameters, the main injection area of ​​the vortex vibration energy of the fan blade under each order mode can be determined to obtain the final vortex-induced vibration area, that is, Figure 7 The circled area is arranged with an anti-vortex excitation device in the circled area to improve the anti-vortex excitation effect.

[0111] When the airflow passes through the fan blades, periodic alternating vortices will be generated in the wake on both sides of the fan blades, causing periodic changes in the surface of the fan blades, thereby generating periodic vortex-induced forces on the fan blades. When the wind speed increases to a certain value, the vortex-shedding frequency is close to the natural frequency of the fan blades, which will stimulate the fan blades to produce vortex-induced resonance. In actual work, vortex-induced vibration in the swing direction is prone to occur after the blades are transported and hoisted and before they are connected to the grid, so it is necessary to obtain the natural frequencies of each order of the fan blades.

[0112] When the fan blades undergo vortex resonance, their amplitude will increase significantly, causing a violent interaction between the movement of the fan blades and the airflow, which is called the aeroelastic effect. This aeroelastic effect will cause the vortex shedding frequency to be controlled by the natural frequency of the fan blades, that is, when the wind speed changes and causes the Storaha frequency to deviate from the natural frequency of the fan blades to a certain extent, the vortex shedding frequency will still be controlled and locked near the natural frequency of the fan blades. In other words, when the fan blades undergo vortex excitation frequency, the vortex excitation frequency will not change with wind speed changes within a certain wind speed range. Therefore, the vortex-induced vibration area can be calculated using three calculation methods, and finally the main injection area of ​​the vortex vibration energy of the fan blades under each mode order is calculated, that is, the final vortex-induced vibration area.

[0113] Figure 8 1 is a schematic block diagram of a computer device 100 according to an embodiment of the present invention. Figure 8 As shown, this embodiment also provides a computer device 100, the computer device 100 includes a memory 120, a processor 110 and a machine executable program 130 stored in the memory 120 and running on the processor 110, and the processor 110 implements the calculation method in any of the above embodiments when executing the machine executable program. The processor 110 can be a central processing unit (CPU), or a digital processing unit, etc. The processor 110 sends and receives data through a communication interface. The memory 120 is used to store the machine executable program 130 executed by the processor 110. The memory 120 is any medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, and can also be a combination of multiple memories 120. The above-mentioned calculation program can be downloaded from a computer-readable storage medium to a corresponding calculation / processing device or downloaded to a computer or an external storage device via a network (such as the Internet, a local area network, a wide area network and / or a wireless network). Here, the memory 120 and the processor 110 can be integrated together or separately set.

[0114] Fig. 9 is a schematic structural diagram of an anti-vortex-induced vibration device 300 installed in a vortex-induced vibration region of a fan blade 200 according to an embodiment of the present invention. Fig.10 yes Fig. 9 A schematic enlarged view of part A in the figure. Fig.11 is a schematic structural diagram of an anti-vortex excitation device 300 according to an embodiment of the present invention, Fig.12 is a schematic structural diagram of an anti-vortex excitation device 300 according to another embodiment of the present invention, Fig.13 is a schematic structural diagram of an anti-vortex excitation device 300 according to yet another embodiment of the present invention. Fig.14 FIG. 3 is a schematic structural diagram of an anti-vortex excitation device 300 according to another embodiment of the present invention. Figures 9 to 14 As shown, in a specific embodiment, the anti-vortex excitation device 300 of the fan blade 200 is arranged in the vortex-induced vibration area of ​​the fan blade 200, and the anti-vortex excitation device 300 includes at least one group of inclined spoiler block groups 310 and at least one group of span-wise spoiler strip groups 320. Each group of inclined spoiler block groups 310 includes at least a first inclined spoiler block 311 arranged at the leading edge of the fan blade 200 and at least one second inclined spoiler block 312 arranged at the trailing edge of the fan blade 200, and the first inclined spoiler block 311 and the second inclined spoiler block 312 are both inclined to extend out of the fan blade 200. Each group of span-wise spoiler strips includes at least one first span-wise spoiler strip 321 arranged at the leading edge of the blade and at least one second span-wise spoiler strip 322 arranged at the trailing edge of the blade, and the first span-wise spoiler strip 321 and the second span-wise spoiler strip 322 are both arranged along the extension direction of the fan blade 200. Here, the first inclined spoiler block 311, the second inclined spoiler block 312, the first span-wise spoiler strip 321 and the second span-wise spoiler strip 322 are all mounted on the fan blade 200 by means of a binding band, and the vortex shedding frequency of the cross section of the fan blade 200 can be changed by changing the chord length of the fan blade 200, thereby affecting the injection of vortex vibration energy. The first inclined spoiler block 311 and the second inclined spoiler block 312 of each group of inclined spoiler block groups 310 can be understood as being in the same phase of the fan blade 200. The first span-wise spoiler strip 321 and the second span-wise spoiler strip 322 of each group of span-wise spoiler strip groups 320 can be understood as being in the same phase of the fan blade 200.

[0115] See also Figures 11 to 14 , there are multiple groups of inclined spoiler block groups 310, there are multiple groups of spanwise spoiler strip groups 320, and the multiple groups of inclined spoiler block groups 310 and the multiple groups of spanwise spoiler strip groups 320 are arranged alternately along the extension direction of the fan blade 200. In this embodiment, the spanwise spoiler strips are closely arranged between two adjacent groups of inclined spoiler block groups 310, so that the outer dimensions of the fan blade 200 are continuously disturbed, destroying the continuous energy injection along the blade span.

[0116] See also Fig.11 The first inclined spoiler block 311 and the second inclined spoiler block 312 are both inclined and protrude from the fan blade 200 , and the inclination angle is determined according to specific design requirements. Preferably, the first inclined spoiler block 311 and the second inclined spoiler block 312 are symmetrically arranged along the center line of the fan blade 200 .

[0117] In some embodiments, the first inclined spoiler block 311 and the second inclined spoiler block 312 in each inclined spoiler block group 310 are both inclined toward the tip direction of the fan blade 200 or are both inclined toward the root direction of the fan blade 200. Fig.11 That is to say, the first inclined spoiler block 311 and the second inclined spoiler block 312 in each inclined spoiler block group 310 are inclined toward the left side or toward the right side.

[0118] See also Fig.11 and Fig.12 In some embodiments, the first inclined spoiler blocks 311 in two adjacent inclined spoiler block groups 310 have opposite inclination directions, and the second inclined spoiler blocks 312 have opposite inclination directions. Here, if the first inclined spoiler blocks 311 in one group are inclined toward the blade root direction of the fan blade 200, then the first inclined spoiler blocks 311 in the other group are inclined toward the blade tip direction of the fan blade 200. If the second inclined spoiler blocks 312 in one group are inclined toward the blade root direction of the fan blade 200, then the second inclined spoiler blocks 312 in the other group are inclined toward the blade tip direction of the fan blade 200. The first inclined spoiler blocks 311 and the second inclined spoiler blocks 312 in each inclined spoiler block group 310 have the same inclination direction.

[0119] See also Fig.13 and Fig.14 In some embodiments, the inclination directions of the first inclined spoiler blocks 311 in the plurality of inclined spoiler blocks groups 310 are consistent, and the inclination directions of the second inclined spoiler blocks 312 are consistent.

[0120] See also Figures 11 to 14 , the first inclined spoiler block 311 in each inclined spoiler block group 310 is arranged on the pressure side or the suction side of the fan blade 200, and the second inclined spoiler block 312 is arranged on the side opposite to the first inclined spoiler block 311. It can be understood that the first inclined spoiler block 311 in each inclined spoiler block group 310 is arranged on the pressure side of the fan blade 200, and the second inclined spoiler block 312 is arranged on the suction side of the fan blade 200. The first inclined spoiler block 311 in each inclined spoiler block group 310 is arranged on the suction side of the fan blade 200, and the second inclined spoiler block 312 is arranged on the pressure side of the fan blade 200. The spiral arrangement of this embodiment can avoid the fan blade 200 from generating vortex excitation forces in the same phase and avoid vibration excitation.

[0121] See also Figures 11 to 14 In some embodiments, the first inclined spoiler blocks 311 in the plurality of inclined spoiler blocks 310 are all arranged on the pressure side or the suction side of the fan blade 200. It can be understood that the first inclined spoiler blocks 311 in the plurality of inclined spoiler blocks 310 are all arranged on the pressure side of the fan blade 200, and the second inclined spoiler blocks 312 are all arranged on the suction side of the fan blade 200. The first inclined spoiler blocks 311 in the plurality of inclined spoiler blocks 310 are all arranged on the suction side of the fan blade 200, and the second inclined spoiler blocks 312 are all arranged on the pressure side of the fan blade 200.

[0122] See also Figures 11 to 14In some embodiments, the first spanwise spoiler strip 321 in each spanwise spoiler strip group 320 is arranged on the pressure side or the suction side of the fan blade 200, and the second spanwise spoiler strip 322 is arranged on the side opposite to the first spanwise spoiler strip 321. Here, if the first spanwise spoiler strip 321 is arranged on the pressure side of the fan blade 200, the second spanwise spoiler strip 322 is arranged on the suction side of the fan blade 200. If the first spanwise spoiler strip 321 is arranged on the suction side of the fan blade 200, the second spanwise spoiler strip 322 is arranged on the pressure side of the fan blade 200.

[0123] In some embodiments, two groups of first spanwise spoiler strips 321 in two adjacent groups of spanwise spoiler strip groups 320 are respectively arranged on the pressure side and the suction side of the fan blade 200. Here, if the first spanwise spoiler strips 321 of one group are arranged on the pressure side of the fan blade 200, the first spanwise spoiler strips 321 of the other group are arranged on the suction side of the fan blade 200. In addition, if the second spanwise spoiler strips 322 of one group are arranged on the pressure side of the fan blade 200, the second spanwise spoiler strips 322 of the other group are arranged on the suction side of the fan blade 200. The first spanwise spoiler strips 321 and the second spanwise spoiler strips 322 in each group of spanwise spoiler strip groups 320 are respectively arranged on the pressure side and the suction side of the fan blade 200.

[0124] See also Fig.12 and Fig.13 In some embodiments, the first spanwise spoiler strip 321 and the second spanwise spoiler strip 322 in each spanwise spoiler strip group 320 both extend out of the fan blade 200. Fig.11 and Fig.14 In another embodiment, the outermost sides of the first spanwise spoiler strip 321 and the second spanwise spoiler strip 322 in each spanwise spoiler strip group 320 are flush with the fan blade 200, that is, they do not protrude from the fan blade 200, and can be specifically designed according to design requirements.

[0125] This embodiment can arrange the inclined spoiler block groups 310 and the span-wise spoiler strip groups 320 in the calculated final vortex-induced vibration area, install the inclined spoiler block groups 310 every 3 m at the leading edge and the trailing edge of the fan blade 200 by elastic straps, and arrange the span-wise spoiler strip groups 320 closely between the inclined spoiler block groups 310.

[0126] Figures 11 to 14 Four arrangements of the inclined spoiler block group 310 and the span-wise spoiler strip group 320 are shown. In other embodiments, arrangements may also be made according to specific design requirements.

[0127] This embodiment arranges inclined spoiler blocks and span-wise spoiler strips in the vortex-induced vibration area of ​​the fan blade 200. On the one hand, the airflow passing through the fan blade 200 is subjected to significantly irregular disturbances, which can effectively suppress the vortex-induced vibration of the fan blade 200. On the other hand, the vortex-induced vibration area clarifies the arrangement range of the anti-vortex-induced vibration device 300, increases the effectiveness of the anti-vortex-induced vibration device 300, and reduces unnecessary arrangement of the anti-vortex-induced vibration device 300, thereby reducing the impact on the paint surface of the fan blade 200 and the workload of disassembling the anti-vortex-induced vibration device 300.

[0128] At this point, those skilled in the art should recognize that, although multiple exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the content disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all these other variations or modifications.

Claims

1. A method for calculating the vortex-induced resonance area of ​​a fan blade, characterized in that: Includes the following steps Steps: Obtain the natural frequency of the fan blades; Segmenting the fan blade to obtain a plurality of blade sections; Calculating the vortex shedding frequency of each cross section of the blade section at different wind speeds or different working conditions; The vortex shedding frequency and the natural frequency of the cross section of each blade section under different wind speeds or different working conditions are compared to determine the vortex-induced vibration area of ​​the wind turbine blade.

2. The calculation method according to claim 1, characterized in that: The step of respectively calculating the vortex shedding frequency of the cross section of each blade section under different wind speeds or different working conditions specifically includes: Obtaining wind speed information and a cross-sectional airfoil chord length of each blade section; The vortex shedding frequency of the cross section of each blade section at different wind speeds is calculated respectively according to the wind speed information and the cross-sectional airfoil chord length of each blade section.

3. The calculation method according to claim 2, characterized in that: The vortex shedding frequency of each blade section at different wind speeds is calculated according to the following formula: Sr=fD / U Formula (1); Wherein, Sr represents the Strouhal number, f represents the vortex shedding frequency, D represents the cross-sectional airfoil chord length of the blade section, and U represents the wind speed.

4. The calculation method according to claim 1, characterized in that: The step of respectively calculating the vortex shedding frequency of the cross section of each blade section under different wind speeds or different working conditions specifically includes: Simulating the cross section of each blade section at different attack angles and different wind speeds to obtain a modified Strouhal number of the cross section of each blade section under different working conditions, and obtaining the distance between free streamlines at the wake formed by the airflow passing through the cross section of each blade section and the free flow velocity at the flow separation point of the cross section of each blade section; The vortex shedding frequency of the cross section of each blade section under different working conditions is calculated based on the modified Strouhal number, the distance between the free streamlines at the wake formed by the airflow flowing through the cross section of each blade section, and the free flow velocity at the cross-sectional flow separation point of each blade section.

5. The calculation method according to claim 4, characterized in that: The vortex shedding frequency of each blade section under different working conditions is calculated according to the following formula: Universal Sr=fD' / Us formula (2); Wherein, Universal Sr represents the modified Strouhal number, f represents the vortex shedding frequency, Us represents the free flow velocity at the cross-sectional flow separation point of the blade section, and D' represents the distance between free streamlines at the wake formed by the airflow flowing through the cross-sectional area of ​​the blade section.

6. The calculation method according to claim 1, characterized in that: The step of respectively calculating the vortex shedding frequency of the cross section of each blade section under different wind speeds or different working conditions specifically includes: Build a target model; The cross section of each blade section is input into the target model to obtain the vortex shedding frequency of the cross section of each blade section under different working conditions.

7. The calculation method according to claim 6, characterized in that: The step of inputting the cross section of each blade section into the target model to obtain the vortex shedding frequency of the cross section of each blade section under different working conditions specifically includes: Inputting the geometric model of the wind turbine blade into the target model to determine the calculation domain and boundary conditions; Performing grid division and parameter setting on the computational domain; Using dynamic mesh technology and compiling UDF program to realize the movement of the fan blades in the flow field; Performing vortex-induced vibration simulation on the fan blades at different wind speeds and different attack angles; The simulation results are extracted and analyzed by calculation to obtain the vortex shedding frequency of each cross section of the blade section under different working conditions.

8. The calculation method according to claim 1, characterized in that: The step of comparing the vortex shedding frequency and the natural frequency of the cross section of each blade section at different wind speeds or under different working conditions to determine the vortex-induced vibration area of ​​the fan blade further includes: Obtaining the vibration mode amplitude, the corresponding frequency and the corresponding wind speed corresponding to the vortex-induced vibration area; The final vortex-induced vibration region of the fan blade is determined according to the vibration mode amplitude, the corresponding frequency and the corresponding wind speed corresponding to the vortex-induced vibration region.

9. The calculation method according to claim 1, characterized in that: The natural frequency of the fan blade includes a first-order natural frequency and a second-order natural frequency.

10. A computer device, characterized in that: Including a memory, a processor and a storage device A machine executable program is stored in the memory and runs on the processor, and the processor implements the computing method according to any one of claims 1 to 9 when executing the machine executable program.

11. An anti-vortex excitation device for a fan blade, characterized in that: Arranged in the vortex-induced vibration area of ​​the fan blade, the anti-vortex-induced vibration device includes: At least one group of inclined spoiler blocks, each group of the inclined spoiler blocks includes at least a first inclined spoiler block arranged at a leading edge of the fan blade and at least a second inclined spoiler block arranged at a trailing edge of the fan blade, wherein the first inclined spoiler block and the second inclined spoiler block both extend obliquely from the fan blade; and At least one group of spanwise spoiler strip groups, each group of the spanwise spoiler strip groups includes at least one first spanwise spoiler strip arranged at the leading edge of the fan blade and at least one second spanwise spoiler strip arranged at the trailing edge of the fan blade, the first spanwise spoiler strip and the second spanwise spoiler strip are both arranged along the extension direction of the fan blade.

12. The anti-vortex excitation device according to claim 11, characterized in that: There are multiple groups of inclined spoiler block groups, and there are multiple groups of spanwise spoiler strip groups. The multiple groups of inclined spoiler block groups and the multiple groups of spanwise spoiler strip groups are staggered along the extension direction of the fan blade.

13. The anti-vortex excitation device according to claim 12, characterized in that: The first inclined spoiler block and the second inclined spoiler block in each group of the inclined spoiler blocks are both inclined toward the tip direction of the fan blade or are both inclined toward the root direction of the fan blade.

14. The anti-vortex excitation device according to claim 13, characterized in that: The inclination directions of the first inclined spoiler blocks in the plurality of groups of inclined spoiler blocks are consistent, and the inclination directions of the second inclined spoiler blocks are consistent.

15. The anti-vortex excitation device according to claim 13, characterized in that: The inclination directions of the first inclined spoiler blocks in two adjacent groups of inclined spoiler blocks are opposite, and the inclination directions of the second inclined spoiler blocks are opposite.

16. The anti-vortex excitation device according to claim 13, characterized in that: In each group of the inclined spoiler blocks, the first inclined spoiler blocks are arranged on the pressure side or the suction side of the fan blade, and the second inclined spoiler blocks are arranged on the side opposite to the first inclined spoiler blocks.

17. The anti-vortex excitation device according to claim 16, characterized in that: The first inclined spoiler blocks in the plurality of groups of inclined spoiler blocks are all arranged on the pressure side or the suction side of the fan blade.

18. The anti-vortex excitation device according to claim 12, characterized in that: The first spanwise spoiler strips in each spanwise spoiler strip group are arranged on the pressure side or the suction side of the fan blade, and the second spanwise spoiler strips are arranged on the side opposite to the first spanwise spoiler strips.

19. The anti-vortex excitation device according to claim 18, characterized in that: Two groups of the first spanwise spoiler strips in two adjacent groups of the spanwise spoiler strips are respectively arranged on the pressure side and the suction side of the fan blade.

20. The anti-vortex excitation device according to claim 12, characterized in that: The first span-wise spoiler strips and the second span-wise spoiler strips in each span-wise spoiler strip group both extend out of the fan blade.

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