Mooring parameter adjustable ocean engineering model test platform and test method thereof

Abstract

The application discloses a marine engineering model test technology, in particular to a marine engineering model test platform with adjustable mooring parameters and a test method thereof. At the device level, a retractable thin rod is arranged in hinged connection with the platform main body, and a fixed pulley is integrated at the rod end, so as to realize two-dimensional adjustment of the spatial position of the mooring connection point relative to the floating body, thereby completing the model test under different mooring length and angle parameters on a set of device. At the method level, by establishing a mooring point spatial position mapping model, an equivalent mooring stiffness calculation model, a mooring friction compensation correction model and a multi-target parameter optimization function, the adjustment of the mooring parameters is promoted from the trial and error to the model-driven quantitative optimization, thereby significantly improving the test efficiency and the determination accuracy of the optimal mooring scheme.

Description

Technical Field

[0001] This invention relates to a marine engineering model testing technology, and more particularly to a marine engineering model testing platform with adjustable mooring parameters and its testing method. Background Technology

[0002] In the field of marine engineering model testing, such as wave energy devices and breakwaters, the commonly known pool model testing mooring systems typically employ a fixed arrangement. This means that the mooring point is set at a specific location using rigid supports or fixed frames, and the length and angle of the mooring line cannot be adjusted during the test. Such devices require the fabrication of a large number of mooring supports of different sizes, resulting in high testing costs and a large space requirement.

[0003] In existing mooring model tests, the selection of mooring parameters mainly relies on empirical trial-and-error methods, lacking a set of mooring parameter-performance mapping and optimization methods based on mathematical models. This results in a lack of theoretical guidance in the design of test schemes, a large number of test groups, and difficulty in quantitatively determining the optimal mooring scheme. Specifically, this manifests as: (1) the inability to accurately pre-calculate the position parameters of each anchoring point based on the target mooring configuration before the test; and (2) the lack of a method to establish a functional relationship between adjustable parameters such as mooring length, angle, and spring stiffness and the hydrodynamic performance of the floating body and to perform multi-objective optimization.

[0004] A search revealed that CN107091727A discloses an active control mooring test device in air. Its core is to utilize a hydraulic servo system to conduct active hybrid model tests on mooring lines with truncated and full-depth water depths in air, verifying the reliability of truncated control. Its technical approach and application scenario are completely different from the wave-based floating model mooring parameter optimization test of this invention. CN119334593A discloses a mooring model stiffness calibration device and calibration measurement method, which pertains to the calibration measurement equipment for the static stiffness curve of a single mooring cable and does not involve a complete floating model test platform or mooring parameter optimization method.

[0005] The closest technology to this invention is CN117922777A, which discloses a test device and test method based on vortex-induced motion towing test. It uses four sets of obliquely arranged spring groups, unidirectional force sensors and lightweight steel wire ropes to form an equivalent horizontal mooring system, and simulates flow and wave conditions through a trailer system. However, this device still has the following shortcomings in terms of the adjustability of mooring parameters: (1) The mooring line is fixed to the mooring point of the support rod after passing through universal pulleys and truss fixed pulleys. Both the pulleys and the mooring point are installed on the fixed structure of the trailer system. The spatial position of the mooring point cannot be continuously adjusted around the hinge point. When it is necessary to change the mooring angle, the fixed position of the mooring point on the support rod must be manually changed or the pulleys must be rearranged. It is not possible to quickly realize the two-dimensional coupling adjustment of the mooring angle and mooring length on a single device; (2) The mooring line runs from the floating model through universal pulleys and truss fixed pulleys to the mooring point of the support rod. The span is large and there are many guiding links, which affects the measurement accuracy of mooring force and motion response. (3) The device uses a spring assembly to provide restoring force, which can only simulate linear horizontal stiffness. It does not have a controllable electromagnetic load (such as a hysteresis brake combined with a gear and rack mechanism) to simulate the load characteristics of the wave energy conversion device PTO system. Its function is limited to vortex-induced motion testing and it cannot carry out experimental research on wave energy capture efficiency. (4) The method of this device is limited to the derivation of the equivalent horizontal stiffness coefficient and the calculation of the resultant force in the horizontal direction. It lacks a systematic method to establish a response surface mapping relationship between parameters such as mooring length, angle, and spring stiffness and the hydrodynamic performance of the floating body and to optimize the solution. The selection of mooring parameters still depends on empirical trial and error and cannot quantitatively obtain the optimal mooring scheme.

[0006] Chinese invention patent application CN116292137A discloses a method, system, and apparatus for testing a decoupled model of a floating wind turbine. Its main structure includes a mooring system, a floating structure, a wind turbine tower, a turbine nacelle assembly mass block, a wire rope, a pulley system (first pulley, second pulley), a wire rope reel, a servo motor, and a control computer. The mooring system is interconnected with the floating structure and positioned at the test point in the marine engineering pool. The wind turbine tower is fixed to the floating structure and connected to the turbine nacelle assembly mass block. One end of the wire rope is connected to the turbine nacelle assembly mass block, passes through the first and second pulleys, and then connects to the wire rope reel. The pulley system is mounted on an aluminum alloy channel steel and is driven up and down by a cylinder or lead screw to adjust the wire rope connection height. The servo motor is deployed on the pool bank and controls the rotation of the wire rope reel to achieve wire rope winding and unwinding, thereby applying wind load and damping force.

[0007] However, the aforementioned floating wind turbine decoupled model test device still has the following problems and shortcomings in mooring tests: Although the pulley group in the device can be driven up and down by cylinders or lead screws, it can only achieve one-dimensional height adjustment. The pulley group is fixedly installed on aluminum alloy channel steel or the shore of the pool, and cannot rotate around the hinge point in the horizontal plane to change the horizontal action angle of the mooring line. Its mooring system and pulley loading system are distributed on the model body and the shore of the pool. The mooring line span is large and the loading path is long. The dispersed system layout affects the synchronous measurement and comparative analysis of data such as mooring force, floating body motion response and energy capture efficiency. When the test needs to study the influence of different mooring lengths, different mooring angles or different mooring arrangements on the floating body motion response, it is necessary to disassemble and reassemble the pulley bracket or process multiple sets of mooring fixtures of different sizes. It is impossible to quickly achieve two-dimensional coupling adjustment of mooring length and mooring angle on a single device, resulting in high test costs, long preparation cycles, and difficulty in ensuring the reproduction accuracy of the spatial position of the mooring connection point after multiple disassemblies and reassemblies. The main reason for these problems is that the existing technology fixes the pulley block to a rigid channel steel or a fixed structure on the bank of the pool. The spatial position of the pulley is rigidly bound to the horizontal angle of the mooring system. It lacks a structural design that integrates the fixed pulley into the end of a rod that can rotate around the hinge point and is telescopically adjustable. Therefore, it is impossible to achieve arbitrary positioning of the mooring connection point in a two-dimensional plane through simple adjustment.

[0008] In summary, existing marine engineering model test platforms and mooring systems generally suffer from insufficient freedom in adjusting mooring parameters, cumbersome tooling replacement, low system integration, and a lack of model-driven parameter optimization test methods. Therefore, there is an urgent need for a model test platform and test method that can achieve two-dimensional adjustable mooring length and angle, has a compact structure, high integration, and possesses mooring parameter mapping and optimization functions based on mathematical models. Summary of the Invention

[0009] The purpose of this invention is to address the problems in existing marine engineering model test platforms, such as fixed mooring system layout, difficulty in adjustment, high test costs, insufficient accuracy in parameter reproduction, and lack of model-driven mooring parameter optimization test methods. This invention provides a marine engineering model test platform with adjustable mooring parameters and its test method, which can achieve two-dimensional adjustment of mooring length and mooring angle, has a compact structure, high integration, and has mooring parameter mapping and optimization functions based on mathematical models.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: A marine engineering model test platform with adjustable mooring parameters includes a test platform installed on top of a water tank. The test platform is equipped with a sensor power supply and data acquisition box, a hysteresis brake, and a gear and rack meshing mechanism. The bottom of the test platform is hinged to the top of an adjustable-length thin rod, with a fixed pulley installed at the bottom of the thin rod. One end of a mooring line is connected to the mooring eye plate of the float under test. After passing over the fixed pulley, the other end of the mooring line is connected to the rack in the gear and rack meshing mechanism. The other end of the rack is connected to a spring, and the other end of the spring is connected to a fixed anchor point. By adjusting the rotation angle and extension length of the thin rod, the spatial position of the mooring line connection point relative to the float is two-dimensionally adjustable, allowing the mooring line to connect to the float at any angle.

[0011] The test platform is also equipped with a wave height meter support frame that can slide horizontally along the crossbeam of the platform frame and can be extended and raised. The wave height meter is installed on the wave height meter support frame. The wave height meter is arranged at designated measuring points around the floating body to be tested and is used to monitor the wave height and wave environment parameters of the test water area. The wave height meter is powered by a data acquisition box, which collects, stores and transmits the wave height meter data.

[0012] The hysteresis brake is used to provide a controllable electromagnetic load for the mooring cable, simulating the resistance torque under different power generation conditions. The brake is connected in series with one end of a torque-speed sensor, both mounted above the test platform. The other end of the torque-speed sensor is coaxially connected in series with the rack in a gear-rack mechanism, used to transmit and measure in real time the rotational resistance torque provided by the hysteresis brake and the gear speed. The torque-speed sensor is powered by a data acquisition box, which collects, stores, and transmits the data from the torque-speed sensor.

[0013] The gear and rack meshing mechanism includes meshing gears and racks. The gears, along with a torque and speed sensor and a hysteresis brake, are mounted in series on the same shaft. The bidirectional resistance provided by the brake is transmitted to the mooring cable through the meshing rack, and further acts on the test float through the mooring cable. In the test of the oscillating wave energy device, the load characteristics of the power take-off (PTO) system are simulated.

[0014] A tension sensor is connected in series in the mooring line path to measure the tension of the mooring cable in real time. The tension sensor is connected to the data acquisition box to transmit the mooring force signal synchronously to the data acquisition system, so as to realize the synchronous measurement of mooring force, floating body motion, wave environment and energy capture data.

[0015] The top of the thin rod is connected to a hinge seat fixed to the bottom of the test platform via a hinge shaft. The thin rod can rotate freely in the vertical plane around the hinge shaft. An arc-shaped slot is formed on the hinge seat with the hinge shaft as the center, and a through hole is formed on the thin rod at the corresponding position. A locking bolt passes through the arc-shaped slot and the through hole and engages with a locking nut. When the thin rod rotates to the target angle, the locking nut is tightened so that the bolt end face presses against the surface of the hinge seat, locking the thin rod at any rotation angle by friction. The thin rod is a sleeve-type telescopic structure, consisting of an outer sleeve and an inner sliding rod. A locking bolt is provided on the outer sleeve to lock the position of the inner sliding rod. The effective length of the mooring line is adjusted by changing the distance between the fixed pulley at its end and the hinge point through length adjustment.

[0016] Multiple thin rods are provided, arranged symmetrically or asymmetrically around the test platform to simulate a multi-mooring system; the hinge seats of the thin rods are equipped with angle scales for precise adjustment and reproduction of mooring angles; the telescopic sections of the thin rods are equipped with length scales and locking bolts for precise adjustment and fixation of mooring lengths.

[0017] A method for testing marine engineering models with adjustable mooring parameters, comprising: S1: Pre-calculation of target mooring configuration: Based on the hydrodynamic characteristics of the test target buoy and the preset mooring arrangement, the target mooring angles on the wave-facing and wave-avoiding sides are calculated using a mooring point spatial position mapping model. , Target development angle converted to adjustable thin rod α (The angle between the thin rod and the vertically downward direction) and the target telescopic length L This allows us to obtain the preset pose parameters of each rod.

[0018] The spatial mapping model for the mooring point is as follows: a Cartesian coordinate system is established with the buoyancy center of gravity as the origin, the wave propagation direction as the positive X-axis, and the vertically upward direction as the positive Z-axis. The hinge points of the thin rods on the wave-facing and wave-avoiding sides are also described. J 1. J The two coordinates are respectively ( x 1, z 1) ( x 2, z 2) The lengths of the thin rods are respectively L L , L R The unfolding angle is α L , α R The coordinates of the mooring points on the wave-facing and wave-avoiding sides of the floating body are respectively ( x L , z L )and( x R ,z R The test water depth was h The spatial coordinates of the fixed pulley P1 on the wave-facing side (mooring line exit point) are: (1) The spatial coordinates of the fixed pulley P2 on the back wave side (mooring line exit point) are: (2) Then the angle of development of the thin rod α L , α R They are respectively (3) (4) Length of thin rod L L , L R They are respectively (5) (6) Through this model, the physical adjustment parameters ( α , L A one-to-one mapping relationship is established between the mooring space configuration and the mooring geometry, enabling accurate pre-calculation of the mooring geometry before the experiment.

[0019] S2: Mooring parameter preset and test model setup: Based on the calculation results of S1, adjust the adjustable rods to the target angle. α and target length L Then lock them in place so that each fixed pulley reaches the preset spatial position; place the test model in the target position and connect the sensor and data acquisition box.

[0020] S3: Mooring Connection and Pretension Application: Connect one end of the mooring line to the floating mooring point, and the other end, after passing over the corresponding fixed pulley, connects to a spring in series and then to the fixed anchor point; obtain the spring stiffness according to the target mooring stiffness. k s (Unit: N / m) and pre-tension amount, the preset pre-tension is applied by adjusting the spring pre-tension amount.

[0021] S4: Multiphysics Synchronous Excitation and Measurement: The wave generator is activated to produce a target wave spectrum (such as the JONSWAP spectrum or Pierson-Moskowitz spectrum) in the water tank. Wave field data is acquired in real time using a wave height meter. A controllable electromagnetic load is applied through a hysteresis brake to simulate power generation conditions. The torque applied to the gears is collected through a torque and speed sensor. and rotational speed Data is collected by measuring the force on the mooring cable using a tension sensor and measuring the motion of the floating body using a six-degree-of-freedom sensor. All sensors are sampled at a set frequency. (e.g., 100Hz) Synchronous acquisition.

[0022] S5: Mooring Parameters - Performance Response Surface Construction: Changing the Combination of Adjustable Parameters ( β , , k s Repeat steps S1 to S4 for each parameter combination to obtain the floating body motion response and energy capture efficiency under different mooring parameters. η Dataset. (with) β , , k s ) is the independent variable, with η and transmission coefficient As the dependent variable, the mooring parameter-performance response surface is constructed using radial basis function (RBF) or Kriging interpolation methods.

[0023] S6: Determination of optimal mooring parameters: On the response surface constructed in S5, the optimal combination of mooring parameters that satisfies the constraints is solved using a multi-objective parameter optimization function, and the optimal mooring scheme is output.

[0024] The multi-objective parameter optimization function is: based on wave energy capture efficiency η Maximize and transmittance Minimize the objective into two parts, and establish a multi-objective optimization problem: (7) Constraints: (8) in, For capture efficiency, The transmission coefficient is used to characterize wave-damping capability. β The target mooring angle (the angle between the mooring line and the horizontal plane). T m The target damping torque applied to the gear is set by the hysteresis brake and verified by the torque and speed sensor. k s This is the spring stiffness coefficient; β min and β max These are the lower and upper limits of the mooring angle, respectively (determined by the geometry of the test platform and the structure of the floating body). T m,min and T m,max These are the lower and upper limits of the target damping torque, respectively (determined by the adjustable range of the hysteresis brake).k s,min and k s,max These represent the lower and upper limits of the spring stiffness coefficient (determined by the available spring specifications). The optimization solution employs the NSGA-II multi-objective genetic algorithm or a gradient-descent-based sequential quadratic programming (SQP) algorithm. By solving the optimization problem, the optimal combination of mooring parameters that satisfies the engineering constraints is automatically output. β * , T m * , k s * ).

[0025] Furthermore, steps S1 to S6 can be repeatedly executed for symmetrical mooring, asymmetrical mooring, and multi-mooring systems with arbitrary spatial configurations, with each execution independently solving for the optimal parameters of the corresponding configuration.

[0026] The beneficial effects of this invention are: 1. This device hinges an adjustable-length rod to the test platform and integrates a fixed pulley at the rod end, enabling two-dimensional adjustment of the spatial position of the mooring connection point. Through the combined adjustment of rotation and extension of the adjustable-length rod, continuous or discrete changes in mooring length and angle can be achieved on a single device, eliminating the need to fabricate multiple sets of fixed supports or pulley fixtures for different mooring parameters. Compared to existing fixed mooring test devices (such as the pulley block fixedly installed on channel steel in CN116292137A), this significantly reduces test preparation costs and tooling processing time, while avoiding systematic errors caused by repeated disassembly and assembly of tooling of different sizes, thus improving the repeatability and comparability of test data.

[0027] 2. This device integrates the wave height measurement system, damping loading system, adjustable mooring system, and data acquisition system onto a single test platform, resulting in a compact structure and convenient installation and adjustment. During the test, simply loosening or tightening the angle locking mechanism and length locking mechanism of the thin rod allows for rapid adjustment and reproduction of mooring parameters, simplifying operation and increasing test efficiency. By arranging the mooring springs in series above the water surface, stiffness drift caused by underwater corrosion of the springs is avoided. Furthermore, springs of different stiffnesses can be quickly replaced without emptying the water tank, significantly improving test efficiency.

[0028] 3. By applying controllable bidirectional resistance on the mooring line through a gear and rack meshing mechanism, the load characteristics of the wave energy conversion device (PTO) system can be directly simulated. It can be used in conjunction with a hysteresis brake to conduct energy harvesting tests under various damping conditions, or run independently to study the effect of mooring damping on the energy capture of the wave device, significantly expanding the function and applicability of the test platform.

[0029] 4. By establishing a spatial location mapping model for mooring points, the target mooring angle is determined. β Angle of development of thin rod α Length of thin rod L By establishing a precise functional mapping relationship between physical adjustment parameters, the preset position and orientation parameters of each rod can be determined by calculation before the test. This fundamentally changes the traditional method of setting mooring parameters that relies on manual visual inspection and repeated trial and error, and improves the accuracy and efficiency of mooring configuration setting.

[0030] 5. By constructing a mooring parameter-performance response surface and using an objective function for optimal solution, the selection of mooring parameters is upgraded from "empirical trial and error" to "model-driven multi-objective quantitative optimization." Compared with existing empirical trial and error methods, this approach reduces the number of test groups (from hundreds of groups in a comprehensive experiment to dozens of groups required by the response surface method), and allows for comprehensive consideration of capture efficiency and transmission coefficient, automatically outputting the optimal mooring scheme, thus avoiding the subjectivity and bias of empirical judgment.

[0031] 6. This invention is not only applicable to mooring parameter optimization tests of wave energy conversion devices, but can also be extended to model tests of floating structures such as offshore platforms, floating wind turbine foundations, and aquaculture cages. By adjusting the arrangement of multiple thin rods around the platform and combining the optimization methods of S1-S6, it can simulate multi-rod mooring systems with symmetrical, asymmetrical, and arbitrary spatial configurations, demonstrating good versatility and engineering application value. Attached Figure Description

[0032] Figure 1 This is an overall schematic diagram of the invention; Figure 2 This is a schematic diagram of the experimental platform of the present invention; Figure 3 This is a schematic diagram of the connection between the thin rod and the test platform of the present invention; Figure 4 This is a flowchart of the experimental method of the present invention; Figure 5 This is a schematic diagram of the coordinates of the spatial location mapping model of the mooring point in this invention; Among them, 1. water tank, 2. thin rod, 3. wave height meter, 4. wave height meter support frame, 5. test platform, 6. torque and speed sensor, 7. data acquisition box, 8. hysteresis brake, 9. spring, 10. gear and rack meshing mechanism, 11. tension sensor, 12. fixed pulley, 13. mooring line, 14. float, 15. hinge seat, 16. locking bolt, 17. outer sleeve, 18. inner slide rod. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0035] Example 1: like Figure 1 , Figure 2 As shown, the marine engineering model test platform with adjustable mooring parameters in this embodiment includes a test platform 5 spanning and installed on top of the water tank 1. The water tank 1 is a wave-making water tank. In this embodiment, the water tank 1 is 30m long, 1.0m wide, and 1.2m deep, and the test water depth is... h The length is 0.80m, and a wave generator is installed at one end of the water tank 1. The test platform 5 is an aluminum alloy frame structure, which is fixed to the top of the two side walls of the water tank 1 by bolts, and its fixed position can be adjusted along the length of the water tank 1.

[0036] The test platform 5 is equipped with a data acquisition box 7, a hysteresis brake 8, a torque and speed sensor 6, and a gear and rack meshing mechanism 10. The bottom of the test platform 5 is hinged to the top of an adjustable-length thin rod 2, and a fixed pulley 12 is installed at the bottom of the thin rod 2. One end of the mooring line 13 is connected to the mooring eye plate of the float 14 to be tested. After passing around the fixed pulley 12, the other end of the mooring line 13 is connected to the rack in the gear and rack meshing mechanism 10. The other end of the rack is connected to a spring 9, and the other end of the spring 9 is connected to a fixed anchor point. By adjusting the rotation angle and extension length of the thin rod 2, the spatial position of the connection point of the mooring line 13 relative to the float 14 can be adjusted in two dimensions, so that the mooring line 13 can be connected to the float 14 at any angle. In this embodiment, the float 14 is a scaled-down model of an oscillating float-type wave energy device. It is a cuboid float with a length of 0.90m, a width of 0.40m, and a height of 0.20m. Its center of gravity is located at the still water surface, and it has a mooring eye plate on both the wave-facing side and the wave-avoiding side.

[0037] like Figure 3As shown, the top of the thin rod 2 is connected to the hinge seat 15 fixed to the bottom of the test platform 5 via a hinge shaft. The thin rod 2 can rotate freely in the vertical plane around the hinge shaft. The hinge seat 15 has an arc-shaped slot with the hinge shaft as the center, and the thin rod 2 has a corresponding through hole. The locking bolt 16 passes through the arc-shaped slot and the through hole and cooperates with the locking nut. When the thin rod 2 rotates to the target angle, the locking nut is tightened so that the end face of the locking bolt 16 presses against the surface of the hinge seat 15, and the thin rod 2 is locked at any rotation angle by friction. The hinge seat 15 is engraved with an angle scale with the hinge shaft as the center. In this embodiment, the angle adjustment range of the thin rod 2 is 0° to 60°, which is convenient for precise adjustment and reproduction of the mooring angle. The thin rod 2 is a telescopic sleeve structure, consisting of an outer sleeve 17 and an inner slide rod 18. The outer sleeve 17 is provided with a locking bolt for locking the position of the inner slide rod 18, and the inner slide rod 18 is provided with a length scale. In this embodiment, the total length adjustment range of the thin rod 2 is 1.0 to 2.0 m. By adjusting the length, the distance between the fixed pulley 12 at its end and the hinge point is changed, thereby adjusting the effective length of the mooring line 13.

[0038] In this embodiment, four thin rods 2 are arranged symmetrically in pairs at the bottom of the test platform 5, with two on the wave-facing side and two on the wave-avoiding side. The rotation angle and extension length of each thin rod 2 can be adjusted and locked independently. By changing the position and orientation combination of each thin rod 2, symmetrical mooring, asymmetrical mooring, and multi-mooring configurations with different mooring radii can be simulated on a single device.

[0039] The gear and rack meshing mechanism 10 includes a gear and a rack meshing with each other; a hysteresis brake 8 is connected in series with one end of a torque-speed sensor 6, and the other end of the torque-speed sensor 6 is coaxially connected in series with the gear. All three are mounted on the same transmission shaft and are positioned above the test platform 5. The bidirectional resistance torque provided by the hysteresis brake 8 is transmitted to the gear via the torque-speed sensor 6, and then to the mooring line 13 via the meshing rack. This torque further acts on the float 14 through the mooring line 13, simulating the load characteristics of a power take-off (PTO) system in the test of the oscillating wave energy device. In this embodiment, the resistance torque adjustment range of the hysteresis brake 8 is 0–12 N·m. The excitation current is adjusted in real time by the data acquisition box 7 according to the set operating conditions to achieve a controllable electromagnetic load; the gear pitch circle radius… r The length is 50mm, and the rack moves in a horizontal direction.

[0040] A tension sensor 11 is connected in series in the path of the mooring line 13. In this embodiment, the tension sensor 11 is connected in series on the mooring line segment between the outlet side of the fixed pulley 12 and the rack, and is used to measure the tension of the mooring cable in real time. The tension sensor 11 is connected to the data acquisition box 7 and transmits the mooring force signal synchronously to the data acquisition system to realize the synchronous measurement of mooring force, floating body motion, wave environment and energy capture data.

[0041] The test platform 5 is also equipped with a wave height meter support frame 4 that can slide horizontally along the crossbeam of the platform frame and can be extended and raised. Wave height meters 3 are installed on the wave height meter support frame 4. In this embodiment, two wave height meters 3 are set up and arranged at designated measuring points on the wave-facing side and the wave-avoiding side of the float 14, respectively, to monitor the wave height and wave environment parameters of the test water area. The wave height meters 3 are powered by the data acquisition box 7, which collects, stores and transmits the data of the wave height meters 3. The torque and speed sensor 6 is also powered by the data acquisition box 7 and collects its data.

[0042] In this embodiment, the spring 9 and the fixed anchor point are both arranged on the test platform 5 above the water surface, which avoids stiffness drift caused by underwater corrosion of the spring and allows for quick replacement of springs with different stiffnesses without emptying the water tank; the stiffness coefficient of the spring 9 has six optional specifications: 50N / m, 100N / m, 150N / m, 200N / m, 250N / m, and 300N / m.

[0043] When adjusting the mooring parameters, loosen the locking nut, rotate the thin rod 2 around the hinge axis to the target angle scale on the hinge seat 15, and then tighten the locking nut; then loosen the locking bolt on the outer sleeve, extend and retract the inner slide rod to the target length scale, and then tighten the locking bolt. This will allow the fixed pulley 12 to reach the target spatial position, realizing two-dimensional coupling adjustment and precise reproduction of mooring length and mooring angle without changing any tooling.

[0044] Example 2: This embodiment provides a marine engineering model test method with adjustable mooring parameters based on the test platform described in Embodiment 1, such as... Figure 4 As shown, steps S1 to S6 are included. This embodiment uses the two symmetrically moored oscillating buoy wave energy device model from Embodiment 1 as the test object, combined with... Figure 5 The coordinate system shown provides a detailed explanation of each step.

[0045] S1: Pre-calculation of target mooring configuration. The origin of the coordinate system is the center of gravity of the floating body 14. O Based on the direction of wave propagation X The positive direction of the axis is vertically upward. Z Establish a Cartesian coordinate system along the positive axis, such as... Figure 5 As shown. In this embodiment, the test water depth is... h =0.80m; the coordinates of the mooring points on the wave-facing and wave-avoiding sides of buoy 14 are respectively ( x L , z L ) = (-0.20, -0.1)m and ( x R , z R = (0.20, -0.1) m; Top hinge points of the thin rods 2 on the wave-facing and wave-avoiding sides.J 1. J The two coordinates are respectively ( x 1, z 1) = (-0.60, 0.70) m, ( x 2, z 2) = (0.60, 0.70) m; Set the target mooring angle β L = β R =45°.

[0046] According to the mooring point spatial location mapping model, the spatial coordinates of the fixed pulley 12 (mooring line exit point) P1 on the wave-facing side are: (1) The spatial coordinates of the fixed pulley P2 on the back wave side (mooring line exit point) are: (2) Then the unfolding angle of thin rod 2 α L , α R (The angles between the thin rod 2 and the vertically downward direction) are as follows: (3) (4) Length of thin rod 2 L L , L R They are respectively: (5) (6) Substituting the parameters of this embodiment, we obtain equations (1) and (2) as follows: x P1 =-0.90m、 z P1 =-0.80m, x P2 =0.90m z P2 =-0.80m; From equations (3) to (6), we get α L = α R ≈11.3°, L L = L R ≈1.53m. Using this model, the physical adjustment parameters ( α , LA one-to-one mapping relationship is established between the mooring space configuration and the mooring geometry, enabling accurate pre-calculation of the mooring geometry before the experiment, eliminating the need for manual visual inspection and repeated trial and error.

[0047] S2: Mooring parameter preset and test model setup. Based on the calculation results of S1, loosen the locking nuts and bolts of each rod 2, and adjust each rod 2 to the target angle. α =11.3° and target length L =1.53m and lock, so that each fixed pulley 12 reaches the preset spatial position; place the floating body 14 model in the target position in the water tank 1, connect each sensor to the data acquisition box 7, and complete the calibration and zeroing of each measurement channel.

[0048] S3: Mooring Connection and Pretension Application. Connect one end of the mooring line 13 to the mooring eye plate of the float 14, and the other end passes over the corresponding fixed pulley 12, is connected in series with the spring 9, and then connected to the fixed anchor point; in this embodiment, a stiffness coefficient is selected. k s Spring 9 with a pretension of 200 N / m, target pretension T If 0 = 10N, then the preload Δ of spring 9 is... l = T 0 / k s =0.05m, and the preset pretension is applied by adjusting the pretension of spring 9.

[0049] S4: Multiphysics Synchronous Excitation and Measurement. The wave generator is activated to produce the target wave spectrum in tank 1. In this embodiment, a regular wave is used, with a wave height of... H =0.80m, period T =1.2s; wave field data is acquired in real time by wave height meter 3; a constant resistance torque of 1.5 N·m is applied by hysteresis brake 8 to simulate PTO load under power generation conditions, and the torque applied to the gear is acquired by torque speed sensor 6. T m ( t ) and speed ω ( t Data; the force on the mooring cable is measured using tension sensor 11. F s ( t The motion response of the float 14 was measured using a six-degree-of-freedom motion sensor; all sensors were used at a sampling frequency of f s =100Hz synchronous acquisition, single acquisition duration is 120s, each set of working conditions is repeated 3 times and the average value is taken.

[0050] The average capture power of float 14 under various operating conditions is calculated according to Calculation and capture efficiency η = / P w ,in P w The incident wave power is expressed as a unit wavefront width.

[0051] S5: Mooring Parameters - Performance Response Surface Construction. From a mooring perspective. β Target damping torque Tm, spring stiffness coefficient k s Design parameter combinations for adjustable parameters: β Take three horizontal angles: 30°, 45°, and 60°. T m Three levels were selected: 1.0 N·m, 1.5 N·m, and 2.0 N·m. k s Three levels (100 N / m, 200 N / m, and 300 N / m) were selected, resulting in a total of 27 parameter combinations. Steps S1 to S4 were repeated for each parameter combination to obtain the floating body motion response and energy capture efficiency under different mooring parameters. η Dataset; with ( β , T m , k s ) is the independent variable, with η With the transmission coefficient Kt as the dependent variable, the mooring parameter-performance response surface is constructed using the radial basis function (RBF) interpolation method.

[0052] S6: Determination of Optimal Mooring Parameters. On the response surface constructed in S5, the optimal combination of mooring parameters satisfying the constraints is solved using the objective function, with wave energy capture efficiency as the key factor. η Maximize and transmittance Minimize the objective into two parts, and establish a multi-objective optimization problem: (7) Constraints: (8) in, For capture efficiency, The transmission coefficient is used to characterize wave-damping capability. β The target mooring angle (the angle between the mooring line and the horizontal plane). T m The target damping torque applied to the gear is set by the hysteresis brake and verified by the torque and speed sensor. k s This is the spring stiffness coefficient; β min and β max These are the lower and upper limits of the mooring angle, respectively (determined by the geometry of the test platform and the structure of the floating body).T m,min and T m,max These are the lower and upper limits of the target damping torque, respectively (determined by the adjustable range of the hysteresis brake). k s,min and k s,max These represent the lower and upper limits of the spring stiffness coefficient (determined by the available spring specifications). The optimization solution employs the NSGA-II multi-objective genetic algorithm or a gradient-descent-based sequential quadratic programming (SQP) algorithm. By solving the optimization problem, the optimal combination of mooring parameters that satisfies the engineering constraints is automatically output. β * , T m * , k s * ).

[0053] In this embodiment, the constraint range is taken as... β ∈[25°, 65°], T m ∈[0.5, 2.0]N·m, k s ∈[80, 320]N / m; the optimal mooring parameter combination can be obtained by using the NSGA-II multi-objective genetic algorithm.

[0054] Example 3: This embodiment demonstrates an application of an asymmetric configuration for four mooring lines. Four thin rods 2 are arranged radially around the bottom of the test platform 5, corresponding to four mooring lines 13. The spread angle and extension length of each thin rod 2 are calculated according to the mooring point spatial position mapping model in step S1, where the target mooring angles for the two mooring lines on the wave-facing side are set as... β L =30°, the target mooring angle of the two mooring lines on the wave-side is set to... β R =50°, forming an asymmetric mooring configuration; repeat steps S1 to S6 to independently solve for the optimal combination of mooring parameters under this configuration, which can be used to study the influence of mooring asymmetry on the floating body's motion response and energy capture efficiency.

[0055] Furthermore, this invention can also be extended to model tests of floating structures such as offshore platforms, floating wind turbine foundations, and aquaculture cages. By simply adjusting the number of thin rods 2 and their arrangement around the test platform 5 according to the mooring form of the floating structure, multi-rod mooring systems with symmetrical, asymmetrical, and arbitrary spatial configurations can be simulated.

[0056] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A marine engineering model test platform with adjustable mooring parameters, characterized in that, The test platform is mounted on the top of the water tank. The platform is equipped with a sensor power supply and data acquisition box, a hysteresis brake, and a rack and pinion mechanism. The bottom of the test platform is hinged to the top of an adjustable-length thin rod, with a fixed pulley mounted at the bottom of the rod. One end of the mooring line is connected to the mooring eye plate of the float under test. After passing over the fixed pulley, the other end of the mooring line is connected to the rack in the rack and pinion mechanism. The other end of the rack is connected to a spring, and the other end of the spring is connected to a fixed anchor point. By adjusting the rotation angle and extension length of the thin rod, the spatial position of the mooring line connection point relative to the float is two-dimensionally adjustable, allowing the mooring line to connect to the float at any angle. The test platform is also equipped with a wave height meter support frame that can slide horizontally along the crossbeam of the platform frame and can be extended and raised. The wave height meter is installed on the wave height meter support frame. The wave height meter is arranged at designated measuring points around the floating body to be tested. It is used to monitor the wave height and wave environment parameters of the test water area. The wave height meter is powered by a data acquisition box, which collects, stores and transmits the wave height meter data. The top of the thin rod is connected to a hinge seat fixed to the bottom of the test platform via a hinge shaft. The thin rod can rotate freely in the vertical plane around the hinge shaft. An arc-shaped slot is formed on the hinge seat with the hinge shaft as the center, and a through hole is formed on the thin rod at the corresponding position. The locking bolt passes through the arc-shaped slot and the through hole and engages with the locking nut. When the thin rod rotates to the target angle, the locking nut is tightened so that the end face of the bolt presses against the surface of the hinge seat, and the thin rod is locked at any rotation angle by friction. The thin rod is a sleeve-type telescopic structure, consisting of an outer sleeve and an inner slide rod. The outer sleeve is provided with a locking bolt for locking the position of the inner slide rod. The effective length of the mooring line can be adjusted by changing the distance between the fixed pulley at its end and the hinge point. Multiple thin rods are provided, arranged symmetrically or asymmetrically around the test platform to simulate a multi-mooring system; the hinge seats of the thin rods are equipped with angle scales to facilitate precise adjustment and reproduction of mooring angles.

2. The marine engineering model test platform with adjustable mooring parameters as described in claim 1, characterized in that, The hysteresis brake provides a controllable electromagnetic load for the mooring cable, simulating the resistance torque under different power generation conditions. The hysteresis brake is connected in series with one end of the torque-speed sensor, and both are mounted above the test platform. The other end of the torque-speed sensor is coaxially connected in series with the rack in the gear-rack meshing mechanism, used to transmit and measure the rotational resistance torque provided by the hysteresis brake and the speed of the gear in real time. The torque-speed sensor is powered by a data acquisition box, which collects, stores, and transmits the data from the torque-speed sensor.

3. The marine engineering model test platform with adjustable mooring parameters as described in claim 1, characterized in that, The gear and rack meshing mechanism includes meshing gears and racks. The gears, torque and speed sensors, and hysteresis brakes are mounted in series on the same shaft. The bidirectional resistance provided by the hysteresis brake is transmitted to the mooring cable through the meshing rack, and further acts on the test float through the mooring cable.

4. The marine engineering model test platform with adjustable mooring parameters as described in claim 1, characterized in that, A tension sensor is connected in series along the mooring line path to measure the tension of the mooring cable in real time; the tension sensor is connected to the data acquisition box to synchronously transmit the mooring force signal to the data acquisition system.

5. A test method for a marine engineering model test platform with adjustable mooring parameters as described in claim 1, characterized in that, include: S1: Pre-calculation of target mooring configuration: Based on the hydrodynamic characteristics of the test target floating body and the preset mooring arrangement, the preset pose parameters of each rod are obtained by using the mooring point spatial position mapping model; through the mooring point spatial position mapping model, a one-to-one mapping relationship is established between the target unfolding angle and the target telescoping length and the mooring spatial configuration, so as to realize the accurate pre-calculation of mooring geometry before the test. S2: Mooring parameter preset and test model setup: Based on the calculation results of step S1, adjust each adjustable length rod to the target angle and target length and lock them, so that each fixed pulley reaches the preset spatial position; Place the test model at the target location and connect the sensors and data acquisition box; S3: Mooring Connection and Pretension Application: Connect one end of the mooring line to the floating mooring point, and connect the other end to the fixed anchor point after passing over the corresponding fixed pulley and connecting it in series with a spring; obtain the spring stiffness and pretension amount according to the target mooring stiffness, and apply the preset pretension by adjusting the spring pretension amount; S4: Multiphysics Synchronous Excitation and Measurement: The wave generator is started to generate the target wave spectrum in the water tank. Wave field data is collected in real time by a wave height meter. A controllable electromagnetic load is applied by a hysteresis brake to simulate power generation. Torque and speed data applied to the gears are collected by a torque and speed sensor. The force on the mooring cable is measured by a tension sensor. The motion of the floating body is measured by a six-degree-of-freedom sensor. All sensors collect data synchronously at a set sampling frequency. S5: Mooring Parameter-Performance Response Surface Construction: Change the adjustable parameter combination, namely the target mooring angle, the torque applied to the gear, and the spring stiffness coefficient. Repeat steps S1 to S4 for each parameter combination to obtain the floating body motion response and wave energy capture efficiency dataset under different mooring parameters. With the target mooring angle, the torque applied to the gear, and the spring stiffness coefficient as independent variables, and the wave energy capture efficiency and transmission coefficient as dependent variables, construct the mooring parameter-performance response surface using radial basis functions or Kriging interpolation methods. S6: Determination of optimal mooring parameters: On the response surface constructed in step S5, the optimal combination of mooring parameters that satisfies the constraints is solved using a multi-objective parameter optimization function, and the optimal mooring scheme is output.

6. The test method for the marine engineering model test platform with adjustable mooring parameters as described in claim 5, characterized in that, The spatial location mapping model for the mooring point in step S1 is as follows: a Cartesian coordinate system is established with the buoyancy center of gravity as the origin, the wave propagation direction as the positive X-axis, and the vertical upward direction as the positive Z-axis; the target mooring angles on the wave-facing and wave-avoiding sides are respectively... , Hinges of thin rods on the wave-facing and wave-avoiding sides J 1. J The two coordinates are respectively ( x 1, z 1) ( x 2, z 2) The lengths of the thin rods are respectively L L , L R The unfolding angle is α L , α R The coordinates of the mooring points on the wave-facing and wave-avoiding sides of the floating body are respectively ( x L , z L )and( x R , z R The test water depth was h Then the spatial coordinates of the fixed pulley P1 on the wave-facing side are: The spatial coordinates of the fixed pulley P2 on the back wave side are: Then the angle of development of the thin rod α L , α R They are respectively Length of thin rod L L , L R They are respectively 。 7. The test method for the marine engineering model test platform with adjustable mooring parameters as described in claim 5, characterized in that, The multi-objective parameter optimization function in step S6 is: based on wave energy capture efficiency η Maximize and transmittance Minimize the objective into two parts, and establish a multi-objective optimization problem: Constraints: in, β For the target mooring angle, ks This is the spring stiffness coefficient. T m The torque applied to the gear, β min and β max These are the lower and upper limits of the mooring angle, respectively. T m,min and T m,max These are the lower and upper limits of the target damping torque, respectively. k s,min and k s,max These are the lower and upper limits of the spring stiffness coefficient, respectively. The optimization solution adopts the NSGA-II multi-objective genetic algorithm or the gradient descent-based sequential quadratic programming algorithm. By solving the optimization problem, the optimal mooring parameter combination that satisfies the engineering constraints is automatically output.

Images