Rotating blade aerodynamic force and flow field synchronous test system

Abstract

The invention provides a rotary blade aerodynamic force and flow field synchronous test system, which relates to the technical field of wind driven generators, and adopts the scheme that a test smooth surface is formed by a PIV laser, a first light guide arm and a second light guide arm, and a smoke generation device is controlled to generate smog-shaped tracer particles at an air inlet of wind tunnel test equipment; after the wind tunnel testing equipment is started, tracer particles are applied to a flow field testing section where a tested blade is located, when the tested blade passes through a testing light surface, a camera is adopted to conduct flow field testing on the tested blade, a testing result is sent to the testing device, and the testing device obtains the testing result of the camera and sends the testing result to the testing device. And aerodynamic force and flow field tests are carried out on the tested blade based on the test result of the camera to obtain the lift force and the resistance borne by the tested blade, so that the aerodynamic force and surface flow field conditions of the tested blade are obtained.

Description

Technical Field

[0001] The present application relates to the technical field of wind turbines, and in particular to a synchronous testing system for aerodynamic force and flow field of rotating blades. Background Art

[0002] Blades are the rotating parts of wind turbines. They capture wind energy and convert it into mechanical energy, which in turn drives the generator to generate electricity. They play a vital role in capturing and converting wind energy into electrical energy.

[0003] As the core component of wind turbines, the performance of wind turbine blades has an important impact on the power generation efficiency and operation stability of the units. Since wind turbine blades have obvious thickness changes and twist angle distribution in the extension direction, the aerodynamic forces and surface flow fields at different spanwise positions from the root to the tip of the blades are quite different during actual operation, and the surface flow field has obvious three-dimensional complex flow characteristics, which in turn causes complex changes in the aerodynamic fields at different spanwise positions of the blades. Obtaining the aerodynamic forces and surface flow field conditions of the blades during operation is the key to effectively designing blades. How to measure the aerodynamic forces and surface flow field conditions of the blades is one of the technical problems that technicians in this field need to solve urgently. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a rotating blade aerodynamic force and flow field synchronous testing system to implement the testing of the aerodynamic force and surface flow field conditions of the blade.

[0005] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0006] A rotating blade aerodynamic force and flow field testing system, comprising:

[0007] A camera, wherein the camera is used to perform a flow field test on the blade under test when the blade under test passes through the test light surface, and the focus of the camera falls on the test light surface;

[0008] A connecting bracket, the connecting bracket is used to fix the camera and adjust the position of the camera;

[0009] A PIV laser, wherein the PIV laser is used to provide a laser beam to the flow field test area through a first light guide arm and a second light guide arm, and the two laser beams output by the first light guide arm and the second light guide arm form a test light surface in the flow field test area;

[0010] An equipment support platform, used for installing the PIV laser, wherein the equipment support platform is a walkable support platform;

[0011] Wind tunnel test equipment, used to provide the required flow field environment for testing;

[0012] A testing device, used to obtain the test results of the camera, and perform aerodynamic and flow field tests on the tested blade based on the test results of the camera to obtain the lift and drag on the tested blade;

[0013] The smoke generating device is used to generate smoke-like tracer particles at the air inlet of the wind tunnel testing equipment.

[0014] Optionally, in the above-mentioned rotating blade aerodynamic and flow field testing system, the testing device is also used to: phase-lock with the blade under test, and when the blade under test passes through the test light surface, generate a control signal for controlling the camera to perform a flow field test on the blade under test.

[0015] Optionally, in the above-mentioned rotating blade aerodynamic force and flow field testing system, the connecting bracket is fixed to the equipment support platform and moves synchronously with the equipment support platform.

[0016] Optionally, in the above-mentioned rotating blade aerodynamic force and flow field testing system, the equipment support platform is installed in the wake area of ​​the wind turbine under test, and the blade under test is the blade of the wind turbine under test.

[0017] Optionally, in the above-mentioned rotating blade aerodynamic force and flow field testing system, the smoke generating device is specifically used for:

[0018] Adjust the type of smoke generated and the concentration of tracer particles based on user operation.

[0019] Optionally, in the above-mentioned rotating blade aerodynamic force and flow field test system, the test device is further used to: traverse the test conditions in the test condition set, the test condition set stores at least one test condition, and the test condition at least includes a wind tunnel test wind speed and a blade rotation speed;

[0020] Based on the traversed test conditions, the wind tunnel test equipment is controlled to output wind speed and the rotation speed of the blade being tested.

[0021] Optionally, in the above-mentioned rotating blade aerodynamic force and flow field testing system, the first light guide arm and the second light guide arm are also used to: adjust the diffusion angle of the laser beam output by the light guide arm based on user operation.

[0022] Optionally, the above-mentioned rotating blade aerodynamic force and flow field testing system further includes:

[0023] A walking rail, on which the equipment support platform can move, and a walking direction of the walking rail is parallel to the rotation plane of the measured blade.

[0024] Optionally, in the above-mentioned rotating blade aerodynamic and flow field testing system, the testing device is also used to generate walking instructions based on user operations, and the walking instructions are used to control the moving direction and moving speed of the equipment support platform on the walking rail.

[0025] Based on the above technical scheme, the above scheme provided by the embodiment of the present invention forms a test light surface through a PIV laser and a first light guide arm and a second light guide arm, controls a smoke generating device to generate smoke-like tracer particles at the air inlet of the wind tunnel test equipment, and after starting the wind tunnel test equipment, the tracer particles are applied to the flow field test section where the blade under test is located. When the blade under test passes through the test light surface, a camera is used to perform a flow field test on the blade under test, and the test result is sent to the test device. The test device obtains the test result of the camera, and performs aerodynamic force and flow field test on the blade under test based on the test result of the camera, and obtains the lift and drag on the blade under test, thereby obtaining the aerodynamic force and surface flow field conditions of the blade under test. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0027] Figure 1 It is a structural schematic diagram of a rotating blade aerodynamic force and flow field testing system disclosed in an embodiment of the present application;

[0028] Figure 2 A schematic diagram of the structure of a rotating blade aerodynamic force and flow field testing system disclosed in another embodiment of the present application;

[0029] Figure 3 A schematic diagram of the test flow of the rotating blade aerodynamic force and flow field test system disclosed in the embodiment of the present application;

[0030] Figure 4 This is a schematic structural diagram of a rotating blade aerodynamic force and flow field testing system disclosed in yet another embodiment of the present application. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Blade surface flow field testing is an important part of fluid dynamics research. It is of great significance for understanding the aerodynamic performance of blades, optimizing blade design, and improving the operating efficiency of related equipment. The main purpose of blade surface flow field testing is to obtain fluid flow parameters on and near the blade surface, such as velocity, pressure, temperature, flow direction, etc., and then analyze the aerodynamic performance of the blade, such as lift, drag, efficiency, etc. These parameters are crucial for evaluating the rationality of blade design, predicting the performance of blades in actual operation, and optimizing blade design.

[0033] The present application aims to provide a new type of dynamic high-speed rotating blade aerodynamic and flow field synchronous testing technology, which can obtain the instantaneous flow field on the surface of the blade during rotation, and calculate the instantaneous aerodynamic force value at that position, thereby realizing the synchronous acquisition of the aerodynamic force of the dynamic rotating blade and the flow field data around the blade.

[0034] See also Figure 1 and Figure 2 The rotating blade aerodynamic and flow field synchronous testing system disclosed in the embodiment of the present application may include: a camera 1, a connecting bracket 2, a PIV laser 3, an equipment support platform 4, a wind tunnel testing equipment 5, a testing device (not shown) and a smoke generating device 6.

[0035] Regarding the camera 1, the camera 1 is used to perform a flow field test on the blade under test when the blade under test passes through the test light surface 8, and the focus of the camera 1 falls on the test light surface 8. During the flow field test, the camera 1 used is usually a high-speed camera. A high-speed camera has an extremely high shooting rate and resolution, and can capture the movement changes of the fluid in a very short time, and is very suitable for flow field testing.

[0036] The application of high-speed cameras in flow field testing is mainly reflected in the following aspects:

[0037] High frame rate capture: High-speed cameras are capable of capturing thousands or even tens of thousands of frames per second, allowing researchers to capture the details of fluid motion on a microsecond or millisecond timescale based on the captured images.

[0038] High-resolution imaging: High-speed cameras are usually equipped with high-resolution sensors that can capture clear and detailed fluid images, helping researchers to more accurately analyze the motion characteristics of the fluid based on the captured images.

[0039] Non-contact measurement: By shooting tracer particles 11 or naturally existing tiny particles in the fluid with a high-speed camera, non-contact measurement of the fluid velocity field can be achieved, avoiding the interference of traditional contact measurement methods on the fluid flow.

[0040] Real-time data processing: Modern high-speed cameras are usually equipped with powerful data processing capabilities, which can process and analyze the captured images in real time and extract the motion parameters and characteristics of the fluid.

[0041] Regarding the connecting bracket 2, the connecting bracket 2 is used to fix the camera 1 and adjust the position of the camera 1. For example, the camera 1 can be controlled to move arbitrarily in space through the connecting bracket 2 so that the camera 1 is located at the best shooting position.

[0042] Regarding the PIV laser 3, the PIV laser 3 is a particle image velocity laser (Particle Image Velocimetry, PIV for short), and the PIV laser 3 is used to provide a laser beam to the flow field test area through a light guide arm 7 (including a first light guide arm and a second light guide arm), and the two laser beams output by the first light guide arm and the second light guide arm form a test light surface 8 in the flow field test area. PIV technology is a non-contact optical measurement technology that measures the velocity field of the fluid by tracking the movement of tracer particles 11 in the fluid. As a light source, the performance of the PIV laser 3 directly affects the accuracy and reliability of the velocity measurement. The output laser of the PIV laser 3 can transmit the output light source of the PIV laser 3 to the target position through the first light guide arm and the second light guide arm. During the flow field test, the PIV laser 3 emits a pulsed laser beam, which is expanded and focused into a sheet of light through an optical system to illuminate the tracer particles 11 in the flow field. After the laser beam is irradiated on the tracer particles 11, the particles scatter part of the laser light. By shooting these scattered lights with a high-speed camera, a particle image can be generated.

[0043] When the blade under test passes through the test light surface 8, the two laser beams provided by the first light guide arm and the second light guide arm of the laser provide test light sources on the suction surface and pressure surface of the blade under test respectively, so as to simultaneously obtain the overall flow field distribution around the blade under test.

[0044] The light guide arm is mainly composed of the following parts:

[0045] Optical fiber: As the core part of the light guide arm, the optical fiber is responsible for transmitting the laser beam from one end to the other. The optical fiber is made of a high refractive index material wrapped with a low refractive index material to form a slender optical waveguide structure.

[0046] Optical connector: used to connect optical fibers and optical devices to ensure the continuity and stability of optical signals during transmission.

[0047] Reflective lens: In laser light guide arms, especially for laser light guide arms, reflective lenses (such as plane mirrors) are used to change the transmission direction of the laser beam to ensure that the laser beam can be transmitted along the predetermined path.

[0048] Other auxiliary components: such as convex lens (for focusing the laser beam), attenuator (for adjusting the intensity of the laser beam), photodetector (for detecting the state of the laser beam), etc. These components may be used in a specific laser light guide arm structure.

[0049] The working principle of the light guide arm is mainly based on the total reflection characteristics of optical fiber. When light enters a low refractive index material from a high refractive index material, if the incident angle is less than a critical angle, the light will be totally reflected back into the high refractive index material and transmitted along the optical fiber. By adjusting the incident angle of the optical fiber and the degree of bending of the optical fiber, the transmission direction and path of the laser beam can be controlled.

[0050] In the light guide arm, the laser beam is emitted by the laser head, reflected by the reflective lens and transmitted by the optical fiber, and finally reaches the target position. The reflective lens is precisely adjusted at an angle to ensure that the laser beam can be transmitted along the predetermined trajectory.

[0051] Regarding the equipment support platform 4, the equipment support platform 4 serves as a supporting component of the PIV laser 3 and is used to install the PIV laser 3. The equipment support platform 4 is a walkable support platform, that is, the position of the equipment support platform 4 can be moved. By moving the equipment support platform 4, the position of the PIV laser 3 can be adjusted to optimize the position of the PIV laser 3.

[0052] Regarding the wind tunnel test equipment 5, the wind tunnel test equipment 5 is used to provide the required flow field environment for the test. The wind tunnel test equipment 5 is mainly used to simulate the airflow in the real atmospheric environment to test the performance of the tested fan blades in the airflow, so as to obtain relevant aerodynamic characteristic data. The wind tunnel test equipment 5 is equipped with a powerful fan or airflow generator inside, which can generate stable and controllable airflow. These airflows are designed through specific pipes and structures to simulate flow conditions similar to the real atmospheric environment.

[0053] See also Figure 2 The wind tunnel test equipment 5 has a contraction section 51, a rectification section 52 and an outlet section 53. After the wind tunnel test equipment 5 is started, the air enters the contraction section 51 to increase speed, passes through the rectification section 52 to improve the flow quality, and finally passes through the outlet section 53 to provide the required flow field environment for the test; the rotating wind turbine 9 is located in the flow field test section 10, and the blades to be tested are the blades of the rotating wind turbine 9. After the wind tunnel test equipment 5 is started, the tracer ions generated at the outlet section can enter the wind tunnel, be compressed in the contraction section 51, and be rectified by the rectification section 52 and then output from the outlet section 53, and the output missing particles are applied to the flow field test area.

[0054] The test device is used to obtain the acquisition results of the camera 1, and perform aerodynamic and flow field tests on the blade under test based on the test results of the camera 1 to obtain the lift and drag on the blade under test.

[0055] Specifically, the test device is used to complete the flow field data acquisition, calculate the flow field density distribution and pressure distribution around the tested blade, and calculate the lift and drag on the blade according to the control body equation and the momentum conservation equation. Specifically, the test device is used to obtain flow field data, and use the flow field data to iteratively solve the gas state equation, the heat state equation and the NS equation to obtain the density field and pressure field corresponding to the flow field around the blade, and then according to the law of conservation of momentum F=-∫∫Sρ(u•n)(u ∞ -u)dS+∫∫S((p ∞ -p)•n+τ•n)dS, the lift equation of the local blade under test is: L=∫ρa(bb ∞ )dy-∫ρb(bb ∞ )dx-∫(p- p ∞ )dx, the resistance equation of the local blade under test: D=∫ρa(aa ∞ )dy-∫ρb(aa ∞ )dx+∫(p- p ∞ )dy, the lift and drag acting on the local part of the blade under test are calculated.

[0056] Among them, F is the force vector of the blade, u is the velocity vector of the flow field, and u ∞ is the velocity vector at the free flow position, n is the unit vector in the normal direction outside the control volume boundary, ρ is the flow field density, p is the pressure value in the flow field, and p ∞ is the pressure value at the free flow position, τ is the viscous stress tensor, and S is the boundary area of ​​the control volume. a and b represent the velocity components of the velocity in the x and y directions in the flow field, respectively. a ∞ and b ∞ is the velocity component of the free flow velocity along the x and y directions. a and b represent the velocity components of the velocity in the flow field in the x and y directions, respectively. ∞ and b ∞ is the velocity component of the free flow velocity along the x and y directions. Among them, lift L and drag D are the two forces decomposed from F.

[0057] The smoke generating device 6 is used to ignite the smoke cake 8 before the contraction section (entrance side) of the wind tunnel test equipment 5 to generate a large amount of smoke-like tracer particles 11 so that the tracer particles 11 enter the wind tunnel.

[0058] When the rotating blade aerodynamic and flow field test system disclosed in this application is used to perform flow field testing, refer to Figure 3 , the main process includes:

[0059] Step S1, use a high-speed camera to detect the flow field around the blade under test. In this solution, the camera 1 can be fixedly connected to the equipment support platform 4 through the connecting bracket 2, and the relative position of the two can be adjusted by adjusting the connecting bracket 2. The position of the camera 1 and the PIV laser 3 can be adjusted by moving the equipment support platform 4, so that the camera 1 and the PIV laser 3 reach the optimal position.

[0060] Step S2: The PIV laser 3 provides a laser beam to the flow field test area through the light guide arm 7. Figure 4 The two laser beams output by the first light guide arm and the second light guide arm overlap in the flow field test area to form a test light surface 8. When the blade under test enters the test light surface 8 during the rotation process, the high-speed camera 1 performs image acquisition on the test light surface 8 to complete the flow field test;

[0061] Step S3: When testing the flow field, the wind tunnel test equipment 5 is first started, and the outlet wind speed of the outlet section 11 is changed by adjusting the wind tunnel motor power of the wind tunnel test equipment 5 to provide the required inflow environment for the rotating wind turbine 913, and the rotation speed of the rotating wind turbine 913 is controlled to reach the required experimental rotation speed. The smoke generating device 6 is controlled to ignite the smoke cake 8 in front of the wind tunnel contraction section (the air inlet of the wind tunnel test equipment 5) to generate a large amount of smoke-like tracer particles 11 to enter the wind tunnel.

[0062] Step S4, after the ion concentration in the test light surface 87 area reaches the test requirement, when the blade under test enters the test light surface 8 area 8 during the rotation process, the high-speed camera 1 is used to collect images;

[0063] Step S5: The testing device obtains the acquisition result of the camera 1, and performs aerodynamic and flow field tests on the blade under test based on the test result of the camera 1 to obtain the lift and drag on the blade under test.

[0064] In the above scheme, in order to form a high-concentration particle distribution on the blade surface, this scheme forms a test light surface 8 through the PIV laser 3 and the first light guide arm and the second light guide arm, and controls the smoke generating device 6 to generate smoke-like tracer particles 11 at the air inlet of the wind tunnel test equipment 5. After starting the wind tunnel test equipment 5, the tracer particles 11 are applied to the flow field test section 10 where the blade under test is located (the test light surface 8 is located in the flow field test section 10). When the blade under test passes through the test light surface 8, the camera 1 is used to perform a flow field test on the blade under test, and the test result is sent to the test device. The test device obtains the test result of the camera 1, and performs aerodynamic and flow field tests on the blade under test based on the test result of the camera 1 to obtain the lift and drag on the blade under test, thereby obtaining the aerodynamic force and surface flow field conditions of the blade under test.

[0065] Each time the present application measures, the lift and drag corresponding to a range area of ​​the measured blade can be obtained. The present application measures the lift and drag at different positions of the measured blade under different working conditions (different rotation speeds and different wind speeds) by adjusting the positions of the camera 1 and the PIV laser 3. Through multiple measurements, the overall lift and drag of the entire measured blade under different working conditions can be obtained.

[0066] In this embodiment, the flow field test can be performed on the tested blade under various different working conditions, and the test working conditions can be controlled by the test device. At this time, the test device is also used to: traverse the test working conditions in the test working condition set, wherein the test working condition set stores at least one test working condition, and the test working condition at least includes the wind tunnel test wind speed and the blade rotation speed; based on the traversed test working conditions, control the wind tunnel test equipment 5 to output the wind speed and the rotation speed of the tested blade, so as to realize the testing of the tested blade under different test working conditions.

[0067] In this embodiment, the camera 1 needs to perform a smoothness test on the flow field test section 10 when the blade under test passes through the test light surface 8. Therefore, it is necessary to ensure that there is a certain degree of synchronization between the test frequency of the camera 1 and the rotation speed of the blade under test. In this embodiment, the test frequency of the camera 1 can be controlled by a test device, and the test device can be phase-locked with the blade under test. When the blade under test passes through the test light surface 8, a control signal for controlling the camera 1 to perform a flow field test on the blade under test is generated. After acquiring the signal, the camera 1 performs a smoothness test on the flow field test section 10.

[0068] In this embodiment, the connecting bracket 2 is fixed on the device support platform 4 and moves synchronously with the device support platform 4. At this time, the camera 1 and the PIV laser 3 can move synchronously driven by the connecting bracket 2 and the device support platform 4. Figure 1 The connecting bracket 2 includes a transverse bracket 21 and a longitudinal bracket 22. The transverse bracket 21 and the longitudinal bracket 22 are perpendicular to each other. Both the transverse bracket 21 and the longitudinal bracket 22 can be retractable structures, and the longitudinal bracket 22 can rotate around the axis of the transverse bracket 21. At this time, the position of the camera 1 can be adjusted by stretching / contracting the transverse bracket 21 and the longitudinal bracket 22 and rotating the transverse bracket 21 on the transverse bracket 21, so that the camera 1 reaches the optimal test position. Furthermore, the camera 1 is installed at the free end of the longitudinal bracket 22, and the free end of the longitudinal bracket 22 can be installed with an angle adjustment structure to achieve 360-degree adjustment of the shooting angle of the camera 1. Of course, the transverse bracket 21 may not have a telescopic function, and the longitudinal bracket 22 can move freely on the transverse bracket 21.

[0069] In this embodiment, a walking rail 12 is also provided, and the equipment support platform 4 can walk on the walking rail 12. The walking direction of the walking rail 12 is parallel to the rotation plane of the measured blade, so that when the measured blade rotates, different positions on it can fall on the test light surface 8, so as to realize the flow field test at different positions of the measured blade in the span direction. In this embodiment, the walking rail 12 can be a slide rail, and the equipment support platform 4 is provided with a slider or roller matching the slide rail, and the slider and roller can move freely on the walking rail 12. Figure 1 , the PIV laser 3 can be arranged on the top of the equipment support platform 4, and the transverse bracket 21 can be fixed on the first side of the equipment support platform 4, and the first side is the side facing the blade to be measured. When the PIV laser 3 moves on the walking guide rail 12, it drives the PIV laser 3 located on the top thereof to move, and at the same time, it also drives the transverse bracket 21 to move. Driven by the transverse bracket 21 and the longitudinal bracket 22, the camera 1 moves with the equipment support platform 4.

[0070] See also Figure 1 In the present application, the first light guide arm and the second light guide arm may both include an upper light guide arm and a lower light guide arm, the upper light guide arm and the lower light guide arm are hinged, and the angle between the upper light guide arm and the lower light guide arm is adjustable. The first end of the upper light guide arm is connected to the PIV laser 3, the first end of the lower light guide arm is connected to the second end of the upper light guide arm, and the laser is output from the second end of the lower light guide arm. By adjusting the angle between the upper light guide arm and the lower light guide arm, the direction of the output laser of the first light guide arm and the second light guide arm can be adjusted.

[0071] In this embodiment, the position of the equipment support platform 4 on the walking rail 12 can be controlled by the testing device, and thus, the testing device is also used to generate walking instructions based on user operations, and the walking instructions are used to control the moving direction and moving speed of the equipment support platform 4 on the walking rail 12.

[0072] In this embodiment, the equipment support platform 4 can be installed in the wake area of ​​the wind turbine under test, and the blade under test is the blade of the wind turbine under test. This setting method can prevent the equipment support platform 4 and the PIV laser 3 from affecting the surface flow field of the blade under test.

[0073] In the technical solution disclosed in this embodiment, the concentration of the tracer particles 11 directly affects the reliability of the flow field test results. The smoke generating device 6 in this application can also adjust the type of smoke generated and the concentration of the tracer particles 11 based on user operations, so that the particle concentration in the flow field test section 10 meets the test requirements. In order to enable the smoke generating device 6 to generate multiple types of tracer particles 11, multiple different types of smoke cakes can be installed in the smoke generating device 6, and different types of smoke cakes can generate different types of tracer ions after being ignited.

[0074] In this embodiment, different blades to be measured have different sizes, and the sizes of the test light surfaces 8 required therefor are also different. Therefore, this scheme also needs to provide test light surfaces 8 of adapted sizes for blades to be measured of different sizes. In this embodiment, the first light guide arm and the second light guide arm are also used to: adjust the diffusion angle of the laser beam output by the light guide arm based on user operation. The diffusion angles of the laser beams output by the first light guide arm and the second light guide arm are different, and the sizes of the test light surfaces 8 formed by the intersection of the two laser beams are different, thereby achieving the goal of providing test light surfaces 8 of different areas for blades to be measured of different sizes.

[0075] It can be seen from the above scheme that in order to form a high concentration of tracer ion distribution on the surface of the blade under test, this application uses smoke cakes to provide tracer particles. The smoke cakes are burned to produce solid particles that enter the flow field before the test section of the experimental rotating wind turbine; the PIV laser is arranged in the wake area of ​​the rotating wind turbine to avoid interfering with the inflow flow field. The laser provides two laser beams on the suction surface and pressure surface of the blade under test, respectively, so that the camera can obtain the overall flow field distribution around the blade under test. The test device calculates the density field and pressure field based on the flow field test data around the blade under test collected by the camera, and uses the momentum conservation equation to calculate the lift and drag on the blade under test, so as to achieve the synchronous acquisition of the flow field and aerodynamic force around the blade.

[0076] In summary, the rotating blade aerodynamic force and flow field testing system disclosed in this application has the following advantages:

[0077] 1. An adjustable flow field test platform is built by cooperating with the walking guide rail 12 and the equipment support platform 4, so as to realize accurate measurement of the flow field at different spanwise positions of the measured blade;

[0078] 2. The equipment support platform 4 and the PIV laser 3 are fixedly installed in the wake area of ​​the wind turbine, which can effectively prevent the equipment support platform 4 and the PIV laser 3 from affecting the surface flow field of the blade being measured;

[0079] 3. The test device can realize the synchronous acquisition of the flow field distribution and local aerodynamic force of the high-speed rotating blade under test;

[0080] 4. The method of burning smoke cakes is used to provide high-concentration solid tracer particles 11 for PIV flow field testing, meeting the flow field testing requirements around high-speed rotating blades.

[0081] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. The above-described system and system embodiments are only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without creative work.

[0082] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0083] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0084] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A rotating blade aerodynamic and flow field testing system, characterized in that: include: A camera, wherein the camera is used to perform a flow field test on the blade under test when the blade under test passes through the test light surface, and the focus of the camera falls on the test light surface; A connecting bracket, the connecting bracket is used to fix the camera and adjust the position of the camera; A PIV laser, wherein the PIV laser is used to provide a laser beam to the flow field test area through a first light guide arm and a second light guide arm, and the two laser beams output by the first light guide arm and the second light guide arm form a test light surface in the flow field test area; An equipment support platform, used for installing the PIV laser, wherein the equipment support platform is a walkable support platform; Wind tunnel test equipment, used to provide the required flow field environment for testing; A testing device, used to obtain the test results of the camera, and perform aerodynamic and flow field tests on the tested blade based on the test results of the camera to obtain the lift and drag on the tested blade; The smoke generating device is used to generate smoke-like tracer particles at the air inlet of the wind tunnel testing equipment.

2. The rotating blade aerodynamic force and flow field testing system according to claim 1, characterized in that: The testing device is also used to: perform phase locking with the blade under test, and when the blade under test passes through the test light surface, generate a control signal for controlling the camera to perform flow field testing on the blade under test.

3. The rotating blade aerodynamic force and flow field testing system according to claim 1, characterized in that: The connecting bracket is fixed on the equipment supporting platform and moves synchronously with the equipment supporting platform.

4. The rotating blade aerodynamic and flow field testing system according to claim 1, characterized in that: The equipment support platform is installed in the wake area of ​​the wind turbine under test, and the blade under test is the blade of the wind turbine under test.

5. The rotating blade aerodynamic force and flow field testing system according to claim 1, characterized in that: The smoke generating device is specifically used for: Adjust the type of smoke generated and the concentration of tracer particles based on user operation.

6. The rotating blade aerodynamic force and flow field testing system according to claim 1, characterized in that: The testing device is further used to: traverse the test conditions in the test condition set, wherein the test condition set stores at least one test condition, and the test condition at least includes a wind tunnel test wind speed and a blade rotation speed; Based on the traversed test conditions, the wind tunnel test equipment is controlled to output wind speed and the rotation speed of the blade being tested.

7. The rotating blade aerodynamic force and flow field testing system according to claim 1, characterized in that: The first light guiding arm and the second light guiding arm are further used to adjust the diffusion angle of the laser beam output by the light guiding arm based on user operation.

8. The rotating blade aerodynamic force and flow field testing system according to claim 1, characterized in that: Also includes: A walking rail, on which the equipment support platform can move, and a walking direction of the walking rail is parallel to the rotation plane of the measured blade.

9. The rotating blade aerodynamic force and flow field testing system according to claim 8, characterized in that: The testing device is also used to generate walking instructions based on user operations, and the walking instructions are used to control the moving direction and moving speed of the equipment support platform on the walking guide rail.

Images