Wind tunnel-pool combined loading floating fan distributed hybrid test method

Abstract

The invention discloses a wind tunnel-pool combined loading floating fan distributed hybrid test method, which comprises the following steps of: establishing a floating fan multi-body / multi-physical field collaborative reduced scale criterion, dividing a floating fan into two independent physical models and two independent numerical models, and placing the two independent physical models and the two independent numerical models in different laboratories; integrating a physical model, a numerical model, a loading system and a measurement system, and building a floating fan physical-numerical distributed hybrid test platform; and carrying out data interaction and closed-loop control on the physical-numerical hybrid test platform. A fan and a floating platform are adopted as two relatively independent test substructures, test loading or computer simulation can be carried out in different laboratories by establishing different similarity criteria and geometric scale ratios, a collaborative online test and pneumatic-hydrodynamic load loading under the coupling action of wind, waves and flow are carried out through network interaction data, and the test efficiency is improved. The technical problems of environment load high-precision simulation and dynamic coupling response in a reduced scale model test are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of offshore wind power generation, and in particular relates to a wind tunnel-water tank combined loading floating wind turbine distributed hybrid test method. Background Art

[0002] With the rapid development of offshore wind power and the continuous expansion of sea use, exploitable resources in nearshore waters are gradually becoming saturated. Therefore, the offshore wind power industry's expansion into deep waters has become an inevitable trend. Floating wind turbines, due to their suitability for deepwater applications, have become a research hotspot. However, the dynamic response of floating wind turbines in complex marine environments (where wind, waves, and currents interact), as well as the coupled aerodynamic, hydrodynamic, and control effects, are extremely challenging. Traditional numerical simulation methods are limited by theoretical assumptions and computational accuracy, necessitating verification through physical model testing.

[0003] Currently, the primary testing method for floating wind turbine systems is wind-wave-current tank model testing. Unlike traditional floating structures, the giant rotors of deep-sea floating wind turbines are subject to aerodynamic loads, resulting in complex dynamic response characteristics of aerodynamic-hydrodynamic coupling. Scaled model testing requires consideration of the similarity relationship between aerodynamic and hydrodynamic loads. For aerodynamic load simulation of the turbine, viscous and inertial forces dominate, requiring dynamic similarity to adhere to the Reynolds number similarity criterion. For hydrodynamic load simulation of the floating platform and mooring, gravity and inertial forces dominate, requiring dynamic similarity to adhere to the Froude number similarity criterion. These two completely different similarity criteria can easily lead to a "scale conflict" in scaled models of offshore floating wind turbines. This means that under the same length scale and test conditions, it is difficult to maintain simultaneous similarity between the Reynolds number and the Froude number. Strictly applying Froude number similarity results in inaccurate simulation of the scaled model's aerodynamic performance, and vice versa. Furthermore, as wind turbine size increases, the scale effect becomes more pronounced, making it difficult to ensure similarity in model tests and potentially even causing distortion of the aerodynamic-hydrodynamic coupling characteristics. However, due to the irreconcilable conflict between Reynolds number and Froude number similarity, real-time hybrid testing of tank models using floating platforms as test substructures has recently attracted considerable attention and has achieved initial application. The basic idea is to perform aerodynamic numerical simulations using the wind turbine as a numerical substructure, while the floating platform and mooring components are loaded in the tank as test substructures. The aerodynamic loads derived from the numerical simulations are then applied to the physical model in real time via cables, multi-rotor actuators, or fan arrays.

[0004] Chinese invention patent CN119334583A (publication number) proposes a six-degree-of-freedom aerodynamic load simulation system and control method for an offshore floating wind turbine. This system utilizes a real-time hybrid test system for a tank model using a floating platform as the test substructure. This system does not create a scaled model of the wind turbine blades, but instead simulates the six-degree-of-freedom aerodynamic loads of the wind turbine using an array of seven variable-speed fans. The system primarily consists of a wave tank, wave and flow simulation equipment, a floating platform, a tower, a nacelle, and seven variable-speed fans mounted on a fixed support. The fans are arranged in a double concentric circle arrangement and precisely controlled by a brushless electronic speed regulator and controller. The control method employs a closed-loop PID algorithm. By collecting real-time platform motion data, the six-degree-of-freedom load requirements are calculated and converted into fan thrust commands, ultimately generating aerodynamic loads. While this system resolves the "scaling conflict" issue, its aerodynamic loads are derived from numerical calculations using OpenFAST software, which introduces significant simplifications and fails to reflect the complex aerodynamic effects experienced by wind turbines in a real wind farm.

[0005] Chinese invention patent CN117386568A (publication number) proposes a real-time hybrid model test method for multi-fan drives of an offshore floating wind turbine. This system also utilizes a tank model real-time hybrid test system using a floating platform as the test substructure. This system uses a six-fan drive system as the physical actuator, integrating a brushless motor and propeller assembly via a carbon fiber cantilever, and employing load sensors to achieve precise control of thrust and torque. This method involves secondary development of the OpenFAST software, modifying the ElastoDyn module to process the platform's six-degree-of-freedom motion data in real time and generating a dynamic link library for MATLAB / Python. During the test, the multi-sensor system acquires platform motion parameters in real time. The host computer transmits this data to a numerical model to iteratively calculate aerodynamic loads. The fan speed is then adjusted using PWM signals to form a closed-loop control loop. However, this method still fails to reflect the aerodynamic loads experienced by the wind turbine in a real wind farm, making it difficult to study the aerodynamic response of the wind turbine blades.

[0006] Chinese invention patent CN119878463A (publication number) proposes a hybrid physical-numerical scaled model testing method for floating wind turbines. Its core innovation lies in resolving similarity law conflicts in traditional testing through collaborative simulation of physical and numerical models. This method still utilizes a real-time hybrid test system for a water tank model using a floating platform as the test substructure. The implementation process includes: 1) establishing a multi-physics collaborative scaling criterion based on dimensional analysis to decompose the wind turbine structure into a physical model and a numerical model; 2) using a hexarotor propeller and a six-degree-of-freedom platform to load the rotor thrust and float motion calculated by the numerical model, respectively, and monitoring the physical model response in real time using three-dimensional / six-dimensional force sensors; 3) constructing a closed-loop "measurement-numerical calculation-loading" system to achieve real-time interaction at a frequency exceeding 10Hz. However, the numerical float in this patented technology is based on potential flow theory and Morrison's equations. These simplified models may not fully capture nonlinear effects in real environments (such as turbulence and wave breaking). Hybrid testing relies on the accuracy of the numerical model, which may deviate from some of the actual coupling effects.

[0007] Based on the current research status, the mainstream approach is to use a real-time hybrid test system based on a water tank model using a floating platform as the test substructure. The wind turbine blades are used as the numerical substructure, and aerodynamic loads are obtained through numerical simulation. However, the premise for conducting real-time hybrid tests is that the numerical substructure model must be sufficiently accurate. Current aerodynamic numerical models are mainly based on blade element momentum theory and generalized dynamic wake theory, involving many approximate theories and empirical correction formulas, which may introduce large errors in the test. Therefore, the water tank model test system centered on hydrodynamic characteristic simulation can no longer meet the requirements of integrated floating wind turbine testing. It is necessary to establish a test method that can simulate both aerodynamic and hydrodynamic loads simultaneously. Summary of the Invention

[0008] The present invention addresses the deficiencies of the prior art by providing a distributed hybrid test method for floating wind turbines using combined wind tunnel and water tank loading. The method utilizes a distributed hybrid test technique with multiple test substructures, treating the wind turbine and floating platform as two relatively independent test substructures. These structures are designed using different similarity criteria and geometric scale ratios, and are placed in different laboratories for test loading or computer simulation. This solves the problem of aerodynamic-hydrodynamic similarity disharmony. Furthermore, collaborative online testing is conducted between the test substructures via network interactive data, thereby integrating and utilizing the test resources of each laboratory and reproducing aerodynamic and hydrodynamic effects with high quality. Furthermore, the method is suitable for simulating the aerodynamic-hydrodynamic load loading of floating wind turbines under the coupled effects of wind, waves, and flow, thereby solving the technical problems of high-precision simulation of environmental loads and dynamic coupled response in scaled model tests. Furthermore, the test capabilities of the water tank and wind tunnel are combined to simultaneously achieve high-fidelity simulation of aerodynamic and hydrodynamic loads in the test system, thereby fully preserving the fully coupled dynamic characteristics of the floating wind turbine.

[0009] The technical solution adopted by the present invention is: The distributed hybrid test method for floating wind turbines using wind tunnel and water tank combined loading includes the following steps: S1. Establish a multi-body / multi-physics field collaborative scaling criterion for floating wind turbines, and divide the overall structure of the floating wind turbine into a wind turbine physical model, a floating platform physical model, and a numerical model. The wind turbine physical model is placed in a wind tunnel test environment, and the floating platform physical model is placed in a water tank test environment. S2, integrating the wind turbine physical model, floating platform physical model, numerical model, loading system and measurement system to build a floating wind turbine physical-numerical distributed hybrid test platform; S3, data interaction and closed-loop control of physical-numerical hybrid test platform.

[0010] Furthermore, in S1, the method for establishing the floating wind turbine multi-body / multi-physics field collaborative scaling criterion is as follows: The aerodynamic load is equated to the rotor thrust, and the hydrodynamic load is equated to the floating body motion. Based on the dimensional analysis theory, the load-structure-response similarity law is derived, and the multi-body / multi-physics field collaborative scaling criterion for floating wind turbines is established.

[0011] Furthermore, in S1, the wind turbine physical model, floating platform physical model, and numerical model are divided as follows: The scale ratio is determined according to the established scale criterion and the prototype size of the floating wind turbine, and a wind turbine physical model, a floating platform physical model and a numerical model are designed. The wind turbine physical model includes blades, a nacelle and a tower, and the scale model is designed according to an approximate Reynolds similarity relationship, and is located in a wind tunnel test environment for loading. The floating platform physical model includes a floating platform, a tower and an upper truncated mooring, and the scale model is designed according to a Froude similarity relationship, and is located in a water tank test environment for loading. The numerical model is a lower truncated mooring, and a flow field numerical simulation is performed and calculations are performed on a computer system, wherein the wind turbine physical model is set as the first physical substructure, the floating platform physics is the second physical substructure, and the numerical model is the numerical test substructure.

[0012] Furthermore, in S2, the method for constructing the floating wind turbine physical-numerical distributed hybrid test platform is as follows: S2.1, a measurement system and a loading system are respectively provided on the wind turbine physical model and the floating platform physical model through a connecting structure; S2.2, establish the data transmission channel of the test platform, integrate the various data interfaces of the measurement system, the numerical model calculation result files and the input end of the loading system into the same information storage device of the computer, and establish a closed-loop data transmission channel through the computer.

[0013] Furthermore, in S2.1, the measurement system includes a hot wire velocimeter, a first six-component force sensor, a second six-component force sensor, a third six-component force sensor, a fourth six-component force sensor, and a displacement sensor; the loading system includes a first multi-degree-of-freedom loading platform, a loading frame, a second multi-degree-of-freedom loading platform, a third multi-degree-of-freedom loading platform, a fourth multi-degree-of-freedom loading platform, and a fifth multi-degree-of-freedom loading platform.

[0014] Furthermore, in S2.1, the specific setting method of the measurement system and the loading system is: the hot wire velocimeter and the first six-component force sensor are arranged at the top of the tower of the wind turbine physical model, and the first multi-degree-of-freedom loading platform is arranged at the bottom of the tower of the wind turbine physical model; the second six-component force sensor and the fifth multi-degree-of-freedom loading platform are both arranged at the first mooring truncation point of the floating platform physical model; the third six-component force sensor and the third multi-degree-of-freedom loading platform are both arranged at the second mooring truncation point of the floating platform physical model; the fourth six-component force sensor and the fourth multi-degree-of-freedom loading platform are both arranged at the third mooring truncation point of the floating platform physical model; the first mooring truncation point is the connection between the mooring bottom end and the fifth multi-degree-of-freedom loading platform; the second mooring truncation point is the connection between the mooring bottom end and the third multi-degree-of-freedom loading platform; and the third mooring truncation point is the connection between the mooring bottom end and the fourth multi-degree-of-freedom loading platform.

[0015] Furthermore, in S2.2, the data closed-loop transmission channel is as follows: first physical substructure-first six-component force sensor-second physical substructure-second multi-degree-of-freedom loading platform-second six-component force sensor, third six-component force sensor, fourth six-component force sensor-numerical substructure-second physical substructure-third multi-degree-of-freedom loading platform, fourth multi-degree-of-freedom loading platform, fifth multi-degree-of-freedom loading platform-displacement sensor-first physical substructure-first multi-degree-of-freedom loading platform-first six-component force sensor.

[0016] Furthermore, in said S3, the method of data interaction and closed-loop control is as follows: at the end of a time step after the start of the first physical substructure test, the aerodynamic load of the fan is measured by the first six-component force sensor and sent to the computer as a first acquisition signal, and after deducting the influence of the gravity and inertial force of the fan itself and the scale ratio conversion, a first input signal is obtained, which is then sent by the computer to the second multi-degree-of-freedom loading platform for simulation; the tension of the first mooring truncation point is measured by the second six-component force sensor, the tension of the second mooring truncation point is measured by the third six-component force sensor, and the tension of the third mooring truncation point is measured by the fourth six-component force sensor, which are sent to the computer as a second acquisition signal, and when the scale ratio is converted, the first input signal is obtained. After the conversion, a second input signal is obtained, which is input into the numerical model and then the additional displacements of the first mooring truncation point, the second mooring truncation point, and the third mooring truncation point are output as the third acquisition signal. After the scale ratio conversion is performed, the third input signal is obtained, and then the computer simultaneously sends it to the third multi-degree-of-freedom loading platform, the fourth multi-degree-of-freedom loading platform, and the fifth multi-degree-of-freedom loading platform for simulation. The displacement of the floating platform measured by the displacement sensor is used as the fourth acquisition signal, and after the scale ratio conversion is performed, the fourth input signal is obtained, and then the computer sends it to the first multi-degree-of-freedom loading platform as the additional input for the next time step, and gradually advances according to the time step until the expected number of steps or time is reached.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention combines the advantages of wind tunnel testing with those of water tank testing by designing the wind turbine based on an approximate Reynolds number and the floating platform physical model based on a Froude number. The truncated mooring is simulated using numerical substructuring. The wind turbine physical model and the floating platform physical model are loaded in a wind tunnel and a water tank, respectively. The loading system ensures coordination between the boundaries of the two. This allows the combined strengths of wind tunnel testing and water tank testing to be replicated, enabling high-precision simultaneous simulation of aerodynamic and hydrodynamic loads and significantly improving the reliability of the test results.

[0018] 2. The present invention adopts a physical-numerical hybrid test platform. By distributing various test substructures in different laboratories and utilizing network interactive data to realize collaborative online testing, it effectively avoids the limitations of the equipment capabilities of a single laboratory. The introduction of numerical substructures reduces the complexity of physical model production and testing, saves raw material and process costs, and improves test efficiency.

[0019] 3. This invention improves the simulation accuracy of the dynamic response of floating wind turbines in complex environments through closed-loop control and dynamic load matching technology. By collecting data in real time through the detection system and combining it with the calculation results of the numerical model, the input signal of the loading system is dynamically adjusted to ensure the synchronization and coordination of aerodynamic and hydrodynamic loads, providing a high-fidelity experimental method for studying its aerodynamic-hydrodynamic coupling characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the physical model of the fan of the present invention.

[0021] Figure 2 This is a schematic diagram of the physical model of the floating platform of the present invention.

[0022] Figure 3 It is an enlarged view of part A of the present invention.

[0023] Figure 4 This is a flow chart of a distributed hybrid test in a simultaneous loading mode according to an embodiment of the present invention.

[0024] Figure 5 This is a flow chart of a distributed hybrid test in an alternating loading mode according to the second embodiment of the present invention.

[0025] In the figure: 1. Tower; 2. Blade; 3. First multi-DOF loading platform; 4. Loading frame; 5. Third multi-DOF loading platform; 6. Second mooring cutoff point; 7. Floating platform; 8. Second multi-DOF loading platform; 9. Fourth multi-DOF loading platform; 10. Third mooring cutoff point; 11. First mooring cutoff point; 12. Fifth multi-DOF loading platform. DETAILED DESCRIPTION

[0026] The technical solutions of the present invention are clearly and completely described below through embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] Example 1 like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 As shown, the wind tunnel-water tank combined loading floating wind turbine distributed hybrid test method provided by the present invention includes the following steps: S1. Establish a multi-body / multi-physics field collaborative scaling criterion for floating wind turbines, and divide the overall structure of the floating wind turbine into a wind turbine physical model, a floating platform physical model, and a numerical model. The wind turbine physical model is placed in a wind tunnel test environment, and the floating platform physical model is placed in a water tank test environment. Preferably, in S1, the method for establishing the floating wind turbine multi-body / multi-physics field collaborative scaling criterion is as follows: The aerodynamic load is equated to the rotor thrust, and the hydrodynamic load is equated to the floating body motion. Based on the dimensional analysis theory, the load-structure-response similarity law is derived, and the multi-body / multi-physics field collaborative scaling criterion for floating wind turbines is established. Preferably, in S1, the wind turbine physical model, floating platform physical model, and numerical model are divided as follows: The scale ratio is determined according to the established scale criterion and the prototype size of the floating wind turbine, and a wind turbine physical model, a floating platform physical model and a numerical model are designed. The wind turbine physical model includes blades 2, a nacelle and a tower 1, and is designed as a scaled model according to an approximate Reynolds similarity relationship, and is located in a wind tunnel test environment for loading. The floating platform physical model includes a floating platform, a tower 1 and an upper truncated mooring, and is designed as a scaled model according to a Froude similarity relationship, and is located in a water tank test environment for loading. The numerical model is a lower truncated mooring, and a flow field numerical simulation is performed and calculations are performed on a computer system, wherein the wind turbine physical model is set as the first physical substructure; the floating platform physics is the second physical substructure; and the numerical model is the numerical test substructure. Because the mooring cutoff point is a critical node set to address the spatial limitations of the water tank, the complete mooring system is truncated into two parts: the upper cutoff mooring refers to the actual cable section between the floating platform and the mooring cutoff point, which is physically modeled in the water tank; the lower cutoff mooring refers to the section between the mooring cutoff point and the seabed anchor point, which is cut off and cannot be physically simulated. Its mechanical effects are accurately reproduced through computer numerical simulation combined with equivalent forces and motions applied by a multi-degree-of-freedom loading platform installed at the cutoff point, thereby achieving equivalent simulation of the dynamic characteristics of the full-scale mooring system. Specifically, the wind turbine is divided into a wind turbine physical model, a floating platform physical model, and a numerical model. The wind turbine physical model is used as the first physical substructure for simulation in a wind tunnel, while the floating platform physical model is used as the second physical substructure for simulation in a water tank. The lower mooring, which must be truncated due to the depth of the water tank, is used as a numerical model and set as a numerical substructure for calculation. Since the wind turbine physical model and the floating platform physical model are two independent test models, their length scale ratios can be set independently. Among them, the wind turbine physical model and the floating platform physical model both include tower parts, and the towers of the wind turbine physical model and the floating platform physical model only differ in scale ratio. Therefore, the tower data of the floating platform physical model can be loaded onto the tower of the wind turbine physical model through data interaction and used as a command for the wind turbine physical model tower for testing. Similarly, the force and motion information measured by the two physical sub-models can be restored from one physical sub-model to the prototype according to their respective similarity relationships as needed, and then converted from the prototype to the other physical sub-model.

[0028] S2, integrating the wind turbine physical model, floating platform physical model, numerical model, loading system and measurement system to build a floating wind turbine physical-numerical distributed hybrid test platform; Preferably, the method for constructing a physical-numerical distributed hybrid test platform for floating wind turbines in S2 is as follows: S2.1, a measurement system and a loading system are respectively provided on the wind turbine physical model and the floating platform physical model through a connecting structure; Specifically, in S2.1, the measurement system includes a hot wire velocimeter, a first six-component force sensor, a second six-component force sensor, a third six-component force sensor, a fourth six-component force sensor, and a displacement sensor; the loading system includes a first multi-degree-of-freedom loading platform 3, a loading frame 4, a second multi-degree-of-freedom loading platform 8, a third multi-degree-of-freedom loading platform 5, a fourth multi-degree-of-freedom loading platform 9, and a fifth multi-degree-of-freedom loading platform 12; The specific configuration of the measurement system and the loading system is as follows: the hot wire velocimeter and the first six-component force sensor are arranged at the top of the tower 1 of the wind turbine physical model, and the first multi-degree-of-freedom loading platform 3 is arranged at the bottom of the tower 1 of the wind turbine physical model; the second multi-degree-of-freedom loading platform 8 is arranged at the top of the tower 1 of the floating platform physical model and is connected to the loading frame 4, the displacement sensor is arranged on the floating platform of the floating platform physical model, and the second six-component force sensor and the fifth multi-degree-of-freedom loading platform 12 are both arranged at the first mooring cutoff point 11 of the floating platform physical model. The third six-component force sensor and the third multi-degree-of-freedom loading platform 5 are both arranged at the second mooring truncation point 6 of the floating platform physical model; the fourth six-component force sensor and the fourth multi-degree-of-freedom loading platform 9 are both arranged at the third mooring truncation point 10 of the floating platform physical model; the first mooring truncation point 11 is the connection between the mooring bottom end and the fifth multi-degree-of-freedom loading platform 12; the second mooring truncation point 6 is the connection between the mooring bottom end and the third multi-degree-of-freedom loading platform 5; the third mooring truncation point 10 is the connection between the mooring bottom end and the fourth multi-degree-of-freedom loading platform 9.

[0029] Among them, a hot wire velocimeter and a first six-component force sensor are arranged at the top of the tower 1 of the wind tunnel physical model, the hot wire velocimeter is used to measure the wind speed, and the first six-component force sensor is used to measure the top force of the tower 1 in the wind tunnel test; the first multi-degree-of-freedom loading platform 3 is arranged at the bottom of the tower 1, and is used to apply displacement to the tower 1 in the wind tunnel test; the second multi-degree-of-freedom loading platform 8 is arranged at the top of the tower 1 of the floating platform physical model, and is connected to the bottom of the loading frame 4 by bolts, and is used to apply a reaction force to the tower 1 of the floating platform physical model, the displacement sensor is arranged on the floating platform of the floating platform physical model, and is used to measure the displacement value of the floating platform, and the displacement value of the floating platform is loaded to the bottom of the tower 1 of the wind turbine model through data interaction as the displacement command of the tower 1 in the wind turbine physical model, that is: the displacement of the floating platform is equivalent to the displacement of the bottom of the tower 1, but the data interaction between different models still requires scale conversion; the first The second six-component force sensor, the third six-component force sensor, the fourth six-component force sensor, the third multi-degree-of-freedom loading platform 5, the fourth multi-degree-of-freedom loading platform 9, and the fifth multi-degree-of-freedom loading platform 12 are all arranged on the floating platform of the floating platform physical model. The floating platform is composed of three interconnected floating platforms 7. The second six-component force sensor is used to measure the tension of the first mooring truncation point 11 in the water tank test, the third six-component force sensor is used to measure the tension of the second mooring truncation point 6 in the water tank test, and the fourth six-component force sensor is used to measure the tension of the third mooring truncation point 10 in the water tank test; the third multi-degree-of-freedom loading platform 5 is used to apply the displacement of the second mooring truncation point 6 to the floating platform in the water tank test, the fourth multi-degree-of-freedom loading platform 9 is used to apply the displacement of the third mooring truncation point 10 to the floating platform in the water tank test, and the fifth multi-degree-of-freedom loading platform 12 is used to apply the displacement of the first mooring truncation point 11 to the floating platform in the water tank test.

[0030] S2.2, establish a data transmission channel for the test platform, integrate the various data interfaces of the measurement system, the numerical model calculation result files, and the input end of the loading system into the same information storage device of the computer, and establish a closed-loop data transmission channel through the computer; Specifically, in S2.2, the data closed-loop transmission channel is as follows: first physical substructure - first six-component force sensor - second physical substructure - second multi-degree-of-freedom loading platform 8 - second six-component force sensor, third six-component force sensor, fourth six-component force sensor - numerical substructure - second physical substructure - third multi-degree-of-freedom loading platform 5, fourth multi-degree-of-freedom loading platform 9, fifth multi-degree-of-freedom loading platform 12 - displacement sensor - first physical substructure - first multi-degree-of-freedom loading platform 3 - first six-component force sensor; S3, data interaction and closed-loop control of physical-numerical hybrid test platform; Specifically, in S3, the method of data interaction and closed-loop control is as follows: at the end of a time step after the start of the first physical substructure test, the aerodynamic load of the fan is measured by the first six-component force sensor and sent to the computer as a first acquisition signal, and after deducting the influence of the gravity and inertia force of the fan itself and the scale ratio conversion, a first input signal is obtained, and then sent by the computer to the second multi-degree-of-freedom loading platform 8 for simulation; the tension of the first mooring truncation point 11 is measured by the second six-component force sensor, the tension of the second mooring truncation point 6 is measured by the third six-component force sensor, and the tension of the third mooring truncation point 10 is measured by the fourth six-component force sensor and sent to the computer as a second acquisition signal, and the scale ratio conversion is performed. Then, a second input signal is obtained, which is input into the numerical model and then the additional displacements of the first mooring truncation point 11, the second mooring truncation point 6, and the third mooring truncation point 10 are output as the third acquisition signal. After the scale ratio conversion is performed, the third input signal is obtained, and then the computer simultaneously sends it to the third multi-degree-of-freedom loading platform 5, the fourth multi-degree-of-freedom loading platform 9, and the fifth multi-degree-of-freedom loading platform 12 for simulation; the floating platform displacement measured by the displacement sensor is used as the fourth acquisition signal, and after the scale ratio conversion is performed, the fourth input signal is obtained, and then the computer sends it to the first multi-degree-of-freedom loading platform 3 as the additional input for the next time step, and gradually advances according to the time step until the expected number of steps or time is reached.

[0031] Example 2 like Figure 1 、 Figure 2 、 Figure 3 、 Figure 5 As shown, the present invention provides a distributed hybrid test method for floating wind turbines with wind tunnel-tank combined loading. When the time similarity ratios of the wind turbine and the floating scale model are different, the two cannot exchange force and motion information on the boundary at the same time. Therefore, the entire force or motion time series is loaded each time, and the boundary information is exchanged after the loading is completed. If force balance and displacement coordination are not satisfied, a new loading time series is iteratively calculated and a new round of test loading is started. This process is repeated until force balance and displacement coordination are achieved at the substructure boundary. The division method of the first physical substructure, the second physical substructure, and the numerical substructure, as well as the arrangement of the loading system of this test method are the same as those of steps S1 and S2 of the first embodiment. The difference lies in the sub-data interaction strategy and test process in step S3, which are specifically as follows: Step 3: First, a simplified or approximate numerical model of the entire floating wind turbine system is established, and the force time history at the top of the tower 1 and the displacement time history at the first mooring cutoff point 11, the second mooring cutoff point 6, and the third mooring cutoff point 10 are calculated; then, the above displacement and force time history are used as loading targets to carry out a water tank model test; the displacement time history of the floating platform collected in the water tank test is used as the loading target to carry out a wind tunnel model test with the first multi-degree-of-freedom loading platform 3 at the bottom; at the same time, the displacement time history of the first mooring cutoff point 11, the second mooring cutoff point 6, and the third mooring cutoff point 10 collected in the water tank test are used as the loading target. The tension time history of point 10 is sent to the numerical mooring, and the displacement time histories of the first mooring truncation point 11, the second mooring truncation point 6, and the third mooring truncation point 10 are calculated; the force time history of the top of the tower 1 obtained by wind tunnel test measurement and the displacement time histories of the first mooring truncation point 11, the second mooring truncation point 6, and the third mooring truncation point 10 obtained by numerical simulation are then resent to the pool model for test loading; this process is repeated until force balance and displacement coordination are achieved at the top boundary of the tower 1 and the boundaries of the first mooring truncation point 11, the second mooring truncation point 6, and the third mooring truncation point 10.

[0032] For example: the force time history in the boundary conditions of the top of tower 1 and the displacement time history in the boundary conditions of the first mooring truncation point 11, the second mooring truncation point 6, and the third mooring truncation point 10 are both system inputs and system outputs. When the two input time histories and the two output time histories in one iteration step can be considered equal within the tolerance, the parameter can be considered to have converged successfully; similarly, for process quantities, such as the displacement time history at the bottom of tower 1, although there is inevitably an error between the command sent to the first multi-degree-of-freedom loading platform 3 and the actual displacement of the first multi-degree-of-freedom loading platform 3, as long as the error is within the tolerance, it is also judged to be converged. When the convergence of all substructure boundary conditions is achieved, the iteration is completed, that is, the final structural response is obtained, and the test is completed.

[0033] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Therefore, any modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A distributed hybrid test method for floating wind turbines using combined wind tunnel and water tank loading, characterized by: The following steps are involved: S1. Establish a multi-body / multi-physics field collaborative scaling criterion for floating wind turbines, divide the overall structure of the floating wind turbine into a wind turbine physical model, a floating platform physical model, and a numerical model. Place the wind turbine physical model in a wind tunnel test environment, and the floating platform physical model in a water tank test environment. S2, integrating the wind turbine physical model, floating platform physical model, numerical model, loading system and measurement system to build a floating wind turbine physical-numerical distributed hybrid test platform; The measuring system includes a hot wire velocimeter, a first six-component force sensor, a second six-component force sensor, a third six-component force sensor, a fourth six-component force sensor, and a displacement sensor; the loading system includes a first multi-degree-of-freedom loading platform (3), a loading frame (4), a second multi-degree-of-freedom loading platform (8), a third multi-degree-of-freedom loading platform (5), a fourth multi-degree-of-freedom loading platform (9), and a fifth multi-degree-of-freedom loading platform (12); The specific arrangement of the measurement system and the loading system is as follows: a hot wire velocimeter and a first six-component force sensor are arranged at the top of the tower (1) of the wind turbine physical model, and the first multi-degree-of-freedom loading platform (3) is arranged at the bottom of the tower (1) of the wind turbine physical model; the second multi-degree-of-freedom loading platform (8) is arranged at the top of the tower (1) of the floating platform physical model and is connected to the loading frame (4), the displacement sensor is arranged on the floating platform of the floating platform physical model, and the second six-component force sensor and the fifth multi-degree-of-freedom loading platform (12) are both arranged at the first mooring cutoff point (11) of the floating platform physical model; The third six-component force sensor and the third multi-degree-of-freedom loading platform (5) are both arranged at the second mooring truncation point (6) of the floating platform physical model; the fourth six-component force sensor and the fourth multi-degree-of-freedom loading platform (9) are both arranged at the third mooring truncation point (10) of the floating platform physical model; the first mooring truncation point (11) is the connection point between the mooring bottom end and the fifth multi-degree-of-freedom loading platform (12); the second mooring truncation point (6) is the connection point between the mooring bottom end and the third multi-degree-of-freedom loading platform (5); the third mooring truncation point (10) is the connection point between the mooring bottom end and the fourth multi-degree-of-freedom loading platform (9); S3, data interaction and closed-loop control of physical-numerical hybrid test platform.

2. The distributed hybrid test method for floating wind turbines using wind tunnel and water tank combined loading according to claim 1 is characterized by: In S1, the method for establishing the floating wind turbine multi-body / multi-physics field collaborative scaling criterion is as follows: The aerodynamic load is equated to the rotor thrust, and the hydrodynamic load is equated to the floating body motion. Based on the dimensional analysis theory, the load-structure-response similarity law is derived, and the multi-body / multi-physics field collaborative scaling criterion for floating wind turbines is established.

3. The distributed hybrid test method for floating wind turbines using wind tunnel and water tank combined loading according to claim 1 is characterized by: In S1, the division method of the wind turbine physical model, floating platform physical model and numerical model is as follows: The scale ratio is determined according to the established scale criterion and the prototype size of the floating wind turbine, and a wind turbine physical model, a floating platform physical model and a numerical model are designed. The wind turbine physical model includes blades (2), a nacelle and a tower (1), and the scale model is designed according to the approximate Reynolds similarity relationship, and is located in a wind tunnel test environment for loading; the floating platform physical model includes a floating platform, a tower (1) and an upper truncated mooring, and the scale model is designed according to the Froude similarity relationship, and is located in a water tank test environment for loading; the numerical model is a lower truncated mooring, and a flow field numerical simulation is performed and calculations are performed in a computer system, wherein the wind turbine physical model is set as the first physical substructure, the floating platform physics is the second physical substructure, and the numerical model is the numerical test substructure.

4. The distributed hybrid test method for floating wind turbines using wind tunnel and water tank combined loading according to claim 1 is characterized by: In S2, the method for constructing the floating wind turbine physical-numerical distributed hybrid test platform is as follows: S2.1, a measurement system and a loading system are respectively provided on the wind turbine physical model and the floating platform physical model through a connecting structure; S2.2, integrate the various data interfaces of the measurement system, the numerical model calculation result files, and the input end of the loading system into the same information storage device of the computer, and establish a closed-loop data transmission channel through the computer.

5. The distributed hybrid test method for floating wind turbines using wind tunnel and water tank combined loading according to claim 4 is characterized in that: In S2.2, the data closed-loop transmission channel is as follows: first physical substructure-first six-component force sensor-second physical substructure-second multi-degree-of-freedom loading platform (8)-second six-component force sensor, third six-component force sensor, fourth six-component force sensor-numerical substructure-second physical substructure-third multi-degree-of-freedom loading platform (5), fourth multi-degree-of-freedom loading platform (9), fifth multi-degree-of-freedom loading platform (12)-displacement sensor-first physical substructure-first multi-degree-of-freedom loading platform (3)-first six-component force sensor.

6. The distributed hybrid test method for floating wind turbines using wind tunnel and water tank combined loading according to claim 1 is characterized by: In said S3, the method of data interaction and closed-loop control is as follows: at the end of a time step after the start of the first physical substructure test, the aerodynamic load of the fan is measured by the first six-component force sensor and sent to the computer as a first acquisition signal, and after deducting the influence of the gravity and inertia force of the fan itself and the scale ratio conversion, a first input signal is obtained, which is then sent by the computer to the second multi-degree-of-freedom loading platform (8) for simulation; The tension of the first mooring truncation point (11) measured by the second six-component force sensor, the tension of the second mooring truncation point (6) measured by the third six-component force sensor, and the tension of the third mooring truncation point (10) measured by the fourth six-component force sensor are sent to the computer as the second acquisition signal, and after the scale ratio conversion, the second input signal is obtained. After inputting it into the numerical model, the additional displacements of the first mooring truncation point (11), the second mooring truncation point (6), and the third mooring truncation point (10) are output as the third acquisition signal, and after the scale ratio conversion, the third input signal is obtained. Then, the computer simultaneously sends them to the third multi-degree-of-freedom loading platform (5), the fourth multi-degree-of-freedom loading platform (9), and the fifth multi-degree-of-freedom loading platform (12) for simulation; the displacement of the floating platform measured by the displacement sensor is used as the fourth acquisition signal, and after the scale ratio conversion, the fourth input signal is obtained. Then, the computer sends it to the first multi-degree-of-freedom loading platform (3) as the additional input of the next time step, and gradually advances according to the time step until the expected number of steps or time is reached.

Images