Horizontal coaxial tandem double-wind wheel fan aerodynamic performance test platform and working method thereof

Abstract

The present application relates to a kind of horizontal coaxial type tandem double wind wheel fan aerodynamic performance test platform and its working method, wherein horizontal coaxial type tandem double wind wheel fan aerodynamic performance test platform includes wind wheel mechanism, wind wheel spacing adjusting device, transmission mechanism and measurement and control component;The wind wheel mechanism includes blade, fairing and wind wheel main shaft;The wind wheel spacing adjusting device includes chassis and front, rear installation on the length direction of chassis two groups of double-layer slide rail structure, two groups of slide plate assembly and locking mechanism, slide plate assembly and double-layer slide rail sliding fit;Transmission mechanism has two groups of symmetric setting and is respectively installed on two groups of slide plate assembly, and each group of transmission mechanism includes sequentially arranged servo motor, coupling and bearing seat, the measurement and control component includes six-component force sensor and shaft type torque sensor, and the test platform can accurately carry out double wind wheel aerodynamic interference, power characteristic, load characteristic and other test research.

Description

Technical Field

[0001] This invention relates to a horizontal coaxial tandem dual-rotor fan aerodynamic performance testing platform and its working method. Background Technology

[0002] Most current wind turbines adopt a horizontal-axis single-rotor structure, which makes it difficult to improve the wind energy capture efficiency of a single unit. Furthermore, the wake generated by a large single rotor has a significant impact on downstream turbines, leading to a decrease in the overall wind energy capture efficiency of the wind farm. In contrast, horizontal coaxial tandem dual-rotor wind turbines can perform secondary absorption and utilization of wind energy to improve wind energy capture efficiency. Through reasonable layout and optimized operating parameter design, they have significant advantages in improving power generation efficiency and reducing the cost per kilowatt-hour.

[0003] Currently, all aerodynamic performance tests are conducted on single-rotor wind turbines, and no aerodynamic performance test studies have been carried out on horizontal coaxial tandem double-rotor wind turbines. The relevant research methods and theories are still immature.

[0004] Verifying the aerodynamic performance of full-scale floating wind turbines is challenging and costly. Water tank model testing is a cost-effective and efficient research method in the field of wind power. Currently, most wind power research uses the Froude scaling criterion to design wind turbine models at a scale of 1:50 and conduct model tests. With the continuous trend towards ultra-large single-unit capacity of wind turbines, a larger scaling ratio is required for model design to balance the economy and feasibility of scaled-down model testing. However, a large scaling ratio leads to an irreconcilable contradiction between satisfying the Froude similarity criterion and meeting the actual engineering structural processing and assembly requirements. Therefore, this invention provides a horizontal coaxial tandem dual-rotor wind turbine aerodynamic performance testing platform, aiming to solve this problem under large scaling ratio conditions.

[0005] This makes it difficult for scaled-down model wind turbines to simultaneously satisfy geometric similarity, dynamic similarity, and kinetic similarity. As a result, scaled-down models at large scales will have many non-negligible deviations and shortcomings when reflecting the real aerodynamic performance and coupled motion response of the prototype wind turbine. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a large-scale horizontal coaxial tandem dual-rotor wind turbine aerodynamic performance test platform and its working method, which can meet the stiffness and quality requirements of Froude's scaling criterion while also meeting the requirements of actual production. At the same time, it enables the model wind turbine to meet the following requirements: controllability of the distance between the front and rear rotors; adjustability of the rotational speed of the front and rear rotors; similarity of blade aerodynamic performance; measurability of load, and real-time measurement of rotor thrust and torque.

[0007] A horizontal coaxial tandem dual-rotor wind turbine aerodynamic performance test platform, characterized in that it includes a wind turbine mechanism, a wind turbine spacing adjustment device, a transmission mechanism, and a measurement and control component;

[0008] The wind turbine mechanism includes blades, a shroud, and a wind turbine main shaft. The blades are fixedly connected to the shroud by bolts.

[0009] The wind turbine spacing adjustment device includes a base frame and two sets of double-layer slide rail structures installed at the front and rear along the length of the base frame, two sets of slide plate assemblies and a locking mechanism. The slide plate assemblies slide in cooperation with the double-layer slide rails, and the locking mechanism is used to position and lock the slide plate assemblies with the slide rails.

[0010] The transmission mechanism has two symmetrically arranged sets, which are respectively mounted on two sets of slide plate assemblies. Each set of transmission mechanisms includes a servo motor, a coupling, and a bearing housing arranged in sequence. The coupling is used to connect the output shaft of the servo motor and the main shaft of the impeller. The bearing housing constrains the radial runout of the main shaft of the impeller. The output shaft of the servo motor and the main shaft of the impeller are arranged along the sliding direction of the slide plate assembly. Two sets of coaxial impeller mechanisms are installed on the front and rear sides of the base frame.

[0011] The measurement and control components include a six-component force sensor and a shaft torque sensor. The six-component force sensor is installed in series below the base frame, and the shaft torque sensor is installed in series between the wind turbine main shaft and the servo motor output shaft. The shaft torque sensor integrates a speed measurement module so that it can output torque and speed signals synchronously.

[0012] Preferably, the above-mentioned double-layer slide rail structure includes a primary slide rail and a secondary slide rail, and the slide plate assembly includes a primary slide plate and a secondary slide plate; the secondary slide rail is fixed to the base frame, the secondary slide plate slides in conjunction with the secondary slide rail, the primary slide rail is fixedly connected to the secondary slide plate, the primary slide plate slides in conjunction with the primary slide rail, the secondary slide plate slides along the axis of the wind turbine main shaft, and the two sets of transmission mechanisms are respectively fixedly installed on the two sets of primary slide plates.

[0013] Preferably, the above-mentioned servo motor is equipped with a servo drive unit, and the test platform is also equipped with a bus-type multi-axis motion controller. The host computer communicates with the motion controller via Ethernet, and the motion controller communicates with the servo drive unit via an industrial fieldbus.

[0014] Preferably, the blades adopt an airfoil with a high maximum lift coefficient, low minimum drag coefficient, and high maximum lift-to-drag ratio under low Reynolds number conditions. The blade chord length and installation angle are optimized, and the model wind turbine and the prototype wind turbine meet the criteria of geometric similarity, kinematic similarity, and dynamic similarity.

[0015] Preferably, the geometric similarity criterion satisfies:

[0016] In the formula, L represents the characteristic dimension, η is the geometric scaling factor, the subscript f refers to the prototype wind turbine, and m refers to the model wind turbine.

[0017] Preferably, the equations for the motion similarity criterion are as follows:

[0018] ω is the angular velocity of the wind turbine, R is the radius of the blade unit, U is the wind speed, the subscript f refers to the prototype wind turbine, and m refers to the model wind turbine;

[0019] Based on the similarity principle of velocity triangles, the blade element tilt angle γ, pitch angle β, and blade angle of attack α of the model wind turbine and the prototype wind turbine are kept numerically equal, and their corresponding equations are as follows:

[0020] .

[0021] Preferably, the dynamic similarity criterion equation uses the Froude number as the core criterion:

[0022]

[0023] In the formula, Fr is the Froude scaling factor, V is the fluid characteristic velocity, g is the gravitational acceleration, and L is the characteristic dimension.

[0024] Preferably, the above-mentioned double-layer slide rail is provided with limiting holes at both ends, and both the first-level slide rail and the second-level slide rail are high-precision linear slide rails. The slide rail and the slide plate are in ball rolling contact. The bearing seat is provided with two sets of left and right angular contact ball bearings, which are used for radial positioning and axial support of the wind turbine main shaft.

[0025] Preferably, the aforementioned industrial fieldbus is an EtherCAT bus, and the motion controller is able to acquire the position feedback signal from the servo motor encoder.

[0026] The working method of the horizontal coaxial tandem dual-rotor wind turbine aerodynamic performance testing platform of the present invention is characterized by comprising the following steps:

[0027] (1) Complete the assembly and power-on self-test of the test platform according to any one of claims 1-9 to ensure that all components of the test platform that meet the requirements of geometric similarity, motion similarity and dynamic similarity can start working normally;

[0028] (2) Install the test platform on the tower and floating platform, set the test operating parameters, and adjust the wind field and wave field conditions;

[0029] (3) Establish communication connections between the host computer, motion controller, servo drive unit and each sensor, and complete sensor calibration;

[0030] (4) The motion controller sends motion commands to the host computer, and the two sets of servo motors operate independently to drive the front and rear impellers to rotate at the set speed.

[0031] (5) The wind turbine load is collected by a six-component force sensor, and the torque and speed signals are collected synchronously by a shaft torque sensor. The test data are collected and stored synchronously through multiple channels.

[0032] (6) Adjust the double-layer slide rail structure to change the axial distance between the front and rear wind turbines, and repeat steps 2) to 5) to complete multiple sets of working condition tests.

[0033] This invention relates to a horizontal coaxial tandem dual-rotor wind turbine aerodynamic performance testing platform, designed around four core objectives: controllable spacing, adjustable speed, measurable load, and similar performance. It can accurately conduct experimental research on dual-rotor aerodynamic interference, power characteristics, and load characteristics. The model adopts a symmetrical layout, with a high-precision linear guide rail module at the bottom. The front and rear rotor units can slide along the axis and be precisely positioned, achieving continuous adjustment of the rotor spacing. Each rotor is equipped with an independent servo drive system, driven by a rigid main shaft, supporting independent speed control and stepless speed regulation, simulating multiple operating conditions. A series-shaft torque sensor is connected to the rotor main shaft, and an axial thrust sensor (six-component force sensor) is arranged on the base. Combined with a multi-channel synchronous acquisition system, it achieves real-time and accurate measurement of rotor thrust, torque, and speed. The front and rear rotors use completely identical hub structures, blade airfoils, and processing techniques, and are equipped with coaxiality adjustment and dynamic balancing correction mechanisms to ensure highly similar blade aerodynamic performance, guaranteeing the reliability and comparability of test data. The overall structure adopts a high-rigidity support frame and modular design, which is stable, highly resistant to interference, and adaptable to the testing needs of multiple scenarios, providing core hardware support for the optimization of wind turbine tandem layout and aerodynamic performance research.

[0034] Therefore, compared with the prior art, the present invention has the following beneficial effects: the present invention can be matched with the horizontal coaxial tandem dual-rotor wind turbine aerodynamic performance test platform currently in use or not yet put into practical application for simulation experiments; the six-component force sensor can collect complete force data of the tower and store the data using a data storage device; the platform system simultaneously meets the requirements of Froude scaling criterion for stiffness, mass, geometry and center of mass position at large scales. Attached Figure Description

[0035] Figure 1 This is the front view of the wind turbine mechanism;

[0036] Figure 2 This is the front view of the wind turbine spacing adjustment device;

[0037] Figure 3 This is the front view of the transmission mechanism;

[0038] Figure 4This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0039] To make the above features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings for detailed explanation.

[0040] Specific features of the horizontal coaxial tandem dual-rotor fan aerodynamic performance testing platform of this invention:

[0041] (1) The wind turbine spacing adjustment device based on the double-layer slide rail structure adopts a high-precision linear slide rail, and the guide rail is arranged along the wind turbine axis. The transmission mechanism is rigidly connected to the wind turbine mechanism and can slide along the guide rail axis. It is equipped with a locking mechanism (locking parts corresponding to the mounting holes on the guide rail, such as screws, etc.) to realize continuous adjustment and positioning of the wind turbine axis position. The transmission and measurement units of the front and rear wind turbines are respectively installed on independent movable bases.

[0042] (2) A front and rear wind turbine speed control system based on servo control technology enables independent control of the front and rear wind turbines. The output shaft of the servo motor is rigidly connected to the main shaft of the wind turbine through a coupling to ensure transmission efficiency and coaxiality. In constant speed control mode, it can meet the wind turbine speed regulation test requirements under different wind turbine speed conditions. The host computer is mainly responsible for the overall distribution of low-level motion commands, compilation and deployment of control programs, and configuration of global system parameters. The lower computer acts as the core computing hub in the system, specifically responsible for multi-axis trajectory planning and signal response. Its core functions are motion control algorithm calculation, real-time signal response, and trajectory planning. In terms of communication architecture, the host computer and motion controller send commands through Ethernet, while the motion controller and servo drive unit communicate in real time through EtherCAT industrial fieldbus. This ensures that the controller can achieve high-precision signal response and collect encoder position feedback signals, thereby ensuring the control performance of the multi-axis system.

[0043] (3) Based on the similar aerodynamic performance of the wind turbine blades, considering that the model wind turbine operates under low Reynolds number conditions, the optimal criteria for the airfoil are determined as follows: a higher maximum lift coefficient, a lower minimum drag coefficient, and an excellent maximum lift-to-drag ratio. The blade element momentum theory is modified using Glauber's theory and Prandtl theory to obtain the power of the entire wind turbine. The blade chord length and installation angle are optimized using the mode vector pursuit method.

[0044] (4) Based on the symmetrical transmission mechanism of the dual wind turbines, two sets of angular contact ball bearings are used for radial positioning and axial support within the axial support seat of the transmission mechanism to constrain the radial runout of the main shaft and ensure coaxiality. Secondly, a six-component force sensor is directly connected in series below the base frame. This layout allows all loads borne by the wind turbine to act directly on the six-component force sensor through the support seat. The sensor is rigidly connected to the structure, avoiding additional forces from interfering with measurement accuracy. Furthermore, the measurement direction is along the wind turbine axis, and the range covers the maximum aerodynamic thrust of the wind turbine, thus realizing load measurement. For wind turbine torque measurement, a shaft-type torque sensor is used, connected in series between the wind turbine main shaft and the drive motor; it integrates speed measurement functionality, and can simultaneously output torque and speed signals.

[0045] Furthermore, the platform was tested using the following steps:

[0046] Step (1) First, ensure that all components of the horizontal coaxial tandem double-rotor wind turbine aerodynamic performance test platform that meet the requirements of geometric similarity, motion similarity and dynamic similarity can be assembled as required and can start working normally;

[0047] Step (2) Based on the actual test requirements, install the platform completely onto the tower and floating platform, determine the test parameters, and adjust the required wind field and wave field at the same time;

[0048] Step (3) establish a communication connection and calibrate the sensor software parameters;

[0049] Step (4) Open the control software and set the required fan operating parameters.

[0050] Step (5) collects the test results using software, and then the test continues to return to step (2).

[0051] Figure 1 The wind turbine mechanism based on similar aerodynamic performance mainly consists of blades 1, 2, 3, and 4 and fairings 5 ​​and 6. Airfoils such as AG04, AG14, AG24, SD2030, and SD7003 have been widely used in the field of blade redesign. Among them, the AG14 airfoil is selected because it has the best lift coefficient, the lowest drag coefficient, and the best lift-to-drag ratio under low Reynolds number conditions.

[0052] Figure 2The wind turbine spacing adjustment device based on a double-layer slide rail structure mainly consists of primary slide plates 15 and 16, secondary slide plates 17 and 18, primary slide rails 19 and 20, secondary slide rails 21 and 22, and a base frame 23. Two linear guide rail modules are arranged parallel to each other on the longitudinal main beam of the base frame, extending along the wind turbine axis. Their length (200mm) is approximately half that of the main beam of the frame, enabling continuous adjustment and positioning of the wind turbine axial position (550mm-1260mm). The guide rails are high-precision linear slide rails, with ball bearings providing rolling contact between the rails and the sliders, resulting in a low coefficient of friction and smooth sliding, allowing for stable movement of the wind turbine unit. Limiting holes at both ends of the guide rails prevent the sliders from sliding out of range and avoids damage from component collisions. A six-component force sensor 24 is directly connected in series below the base frame 23.

[0053] Figure 3 The central transmission mechanism mainly consists of bearing housings 7 and 8, torque sensors 11 and 12, and servo motors 13 and 14. The front and rear impellers are each equipped with independent servo motors, enabling independent control of the two drive systems. An ACM1H-04A5 servo motor is selected as the main spindle motor, with an output speed range of 0~3000 rpm. The motor and impeller main shaft are rigidly connected via couplings 9 and 10, ensuring transmission efficiency and coaxiality. A Leadshine SMC606BAS bus-type multi-axis motion controller is used. In terms of communication architecture, the host computer and motion controller send commands via Ethernet, while the motion controller and servo drive units communicate in real-time via EtherCAT industrial fieldbus. This ensures that the controller can achieve high-precision signal response and acquire encoder position feedback signals, thereby ensuring the control performance of the multi-axis system.

[0054] The installation steps of the horizontal coaxial tandem double impeller aerodynamic performance test platform of the present invention are as follows: (1) Blades 1, 2, 3, and 4 are connected to the guide shrouds 5 and 6 by bolts to form an impeller mechanism. (2) The slide rails are connected by sliders. The first-level slide rails 19 and 20 and the second-level slide rails 21 and 22 are connected to the second-level slide plates 17 and 18, the base frame 23 and the six-component force sensor 24, which together form an impeller spacing adjustment device. (3) The bearing seats 7 and 8, the couplings 9 and 10, the axial torque sensors 11 and 12, and the servo motor modules 13 and 14 are sequentially axially connected and installed on the first-level slide plates 15 and 16 to form two transmission mechanisms on the left and right. (4) The impeller mechanism, the transmission mechanism and the impeller spacing adjustment device are sequentially combined to realize the installation of a large-scale horizontal coaxial tandem double impeller aerodynamic performance test platform that meets the requirements of geometric similarity, motion similarity and power similarity.

[0055] Compared with the prior art, the present invention has the following advantages: the present invention can be matched with the aerodynamic performance test platform of the horizontal coaxial tandem dual-rotor wind turbine that is currently in use or has not yet been put into practical application for simulation experiments; the six-component force sensor can collect the complete force data of the tower and store the data using the data storage device; the platform system simultaneously meets the requirements of Froude scaling criterion for stiffness, mass, geometry and center of mass position at large scales.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A horizontal coaxial tandem dual-rotor fan aerodynamic performance testing platform, characterized in that, This includes the wind turbine mechanism, wind turbine spacing adjustment device, transmission mechanism, and measurement and control components; The wind turbine mechanism includes blades, a shroud, and a wind turbine main shaft. The blades are fixedly connected to the shroud by bolts. The wind turbine spacing adjustment device includes a base frame and two sets of double-layer slide rail structures installed at the front and rear along the length of the base frame, two sets of slide plate assemblies and a locking mechanism. The slide plate assemblies slide in cooperation with the double-layer slide rails, and the locking mechanism is used to position and lock the slide plate assemblies with the slide rails. The transmission mechanism has two symmetrically arranged sets, which are respectively mounted on two sets of slide plate assemblies. Each set of transmission mechanisms includes a servo motor, a coupling, and a bearing housing arranged in sequence. The coupling is used to connect the output shaft of the servo motor and the main shaft of the impeller. The bearing housing constrains the radial runout of the main shaft of the impeller. The output shaft of the servo motor and the main shaft of the impeller are arranged along the sliding direction of the slide plate assembly. Two sets of coaxial impeller mechanisms are installed on the front and rear sides of the base frame. The measurement and control components include a six-component force sensor and a shaft torque sensor. The six-component force sensor is installed in series below the base frame, and the shaft torque sensor is installed in series between the wind turbine main shaft and the servo motor output shaft. The shaft torque sensor integrates a speed measurement module so that it can output torque and speed signals synchronously.

2. The test platform according to claim 1, characterized in that, The double-layer slide rail structure includes a primary slide rail and a secondary slide rail, and the slide plate assembly includes a primary slide plate and a secondary slide plate. The secondary slide rail is fixed to the base frame, and the secondary slide plate slides in conjunction with the secondary slide rail. The primary slide rail is fixedly connected to the secondary slide plate, and the primary slide plate slides in conjunction with the primary slide rail. The secondary slide plate slides along the axis of the wind turbine main shaft with the primary slide plate. Two sets of transmission mechanisms are respectively fixedly installed on the two sets of primary slide plates.

3. The test platform according to claim 2, characterized in that, The servo motor is equipped with a servo drive unit, and the test platform is also equipped with a bus-type multi-axis motion controller. The host computer communicates with the motion controller via Ethernet, and the motion controller communicates with the servo drive unit via an industrial fieldbus.

4. The test platform according to claim 1, characterized in that, The blades adopt an airfoil with high maximum lift coefficient, low minimum drag coefficient, and high maximum lift-to-drag ratio under low Reynolds number conditions. The blade chord length and installation angle are optimized. The model wind turbine and the prototype wind turbine meet the criteria of geometric similarity, kinematic similarity, and dynamic similarity.

5. The test platform according to claim 4, characterized in that, The geometric similarity criterion satisfies: In the formula, L represents the characteristic dimension, η is the geometric scaling factor, the subscript f refers to the prototype wind turbine, and m refers to the model wind turbine.

6. The test platform according to claim 4, characterized in that, The equation for the motion similarity criterion is: ω is the angular velocity of the wind turbine, R is the radius of the blade unit, U is the wind speed, the subscript f refers to the prototype wind turbine, and m refers to the model wind turbine; Based on the similarity principle of velocity triangles, the blade element tilt angle γ, pitch angle β, and blade angle of attack α of the model wind turbine and the prototype wind turbine are kept numerically equal, and their corresponding equations are as follows: 。 7. The test platform according to claim 4, characterized in that, The dynamic similarity criterion equation uses the Froude number as the core criterion: In the formula, Fr is the Froude scaling factor, V is the fluid characteristic velocity, g is the gravitational acceleration, and L is the characteristic dimension.

8. The test platform according to claim 2, characterized in that, The double-layer slide rail is provided with limiting holes at both ends. Both the first-level slide rail and the second-level slide rail are high-precision linear slide rails. The slide rail and the slide plate are in ball rolling contact. The bearing seat is provided with two sets of left and right angular contact ball bearings. The angular contact ball bearings are used for radial positioning and axial support of the wind turbine main shaft.

9. The test platform according to claim 3, characterized in that, The industrial fieldbus is an EtherCAT bus, and the motion controller can acquire the position feedback signal from the servo motor encoder.

10. A working method for a horizontal coaxial tandem dual-rotor fan aerodynamic performance testing platform, characterized in that, Includes the following steps: (1) Complete the assembly and power-on self-test of the test platform according to any one of claims 1-9 to ensure that all components of the test platform that meet the requirements of geometric similarity, motion similarity and dynamic similarity can start working normally; (2) Install the test platform on the tower and floating platform, set the test operating parameters, and adjust the wind field and wave field conditions; (3) Establish communication connections between the host computer, motion controller, servo drive unit and each sensor, and complete sensor calibration; (4) The motion controller sends motion commands to the host computer, and the two sets of servo motors operate independently to drive the front and rear impellers to rotate at the set speed. (5) The wind turbine load is collected by a six-component force sensor, and the torque and speed signals are collected synchronously by a shaft torque sensor. The test data are collected and stored synchronously through multiple channels. (6) Adjust the double-layer slide rail structure to change the axial distance between the front and rear wind turbines, and repeat steps 2) to 5) to complete multiple sets of working condition tests.

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