Novel offshore structure wind load and rotational inertia collaborative simulation device

Abstract

The invention relates to the technical field of ocean engineering, and discloses a novel offshore structure wind load and rotational inertia collaborative simulation device, in which a center rod is used for being connected with a rotational inertia measuring device; the at least one load executing mechanism can move on the center rod in the axial direction and is locked, and the load executing mechanism is used for simulating the wind load borne by the structure; at least one upper balancing weight can move on the center rod in the axial direction and be locked, and the upper balancing weights are used for preliminarily adjusting the gravity center and inertia of the device. At least one rotational inertia control mechanism can move on the center rod in the axial direction and be locked, the rotational inertia control mechanism comprises a driving mechanism and a weight adjusting mechanism, and the driving mechanism can drive the weight adjusting mechanism to move in the vertical tangential direction of the axis of the center rod and be locked. According to the invention, physical-level collaborative simulation of the wind load and the rotational inertia can be realized, and dynamic response deviation caused by limited wind speed scale can be effectively compensated.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, and in particular to a novel device for simulating wind load and rotational inertia of marine structures. Background Technology

[0002] In marine engineering tank model tests, the study of the dynamic response of large offshore structures such as floating wind turbines and FPSOs is limited by the scaling effect. Physical models typically follow the Froude number similarity criterion, while the wind loads on the superstructure are dominated by the Reynolds number similarity criterion. If wind loads are simulated according to displacement similarity requirements, the required simulated wind speed far exceeds the limits of existing equipment, making it impossible to directly and accurately reproduce the wind loads.

[0003] Existing technologies often employ external torque compensation, but their effectiveness is highly dependent on the precise balancing of rotational inertia. If the rotational inertia, especially around the roll and pitch axes, is not accurately simulated proportionally, the angular acceleration of the model under wind and wave coupling will deviate significantly, inducing distortion of resonance characteristics and even causing test results to deviate severely from actual working conditions. This has led to major accidents such as the mooring anomaly of the West African FPSO and the sinking of the Brazilian P-36 platform.

[0004] Existing load simulation devices, such as array fans and hexacopter thrusters, can reproduce multi-degree-of-freedom aerodynamic loads, but their large weight will change the model's center of gravity and moment of inertia. Furthermore, traditional static counterweights are difficult to dynamically adjust, resulting in a disconnect between load loading and inertia balancing, which limits the accuracy and efficiency of the experiment. Summary of the Invention

[0005] The purpose of this invention is to provide a novel device for simulating wind load and rotational inertia of marine structures, aiming to solve or improve at least one of the aforementioned technical problems.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a novel device for co-simulating wind load and rotational inertia of offshore structures, comprising: The center rod is used to connect to the moment of inertia measuring device; At least one load actuator is capable of moving axially and locking on the central rod, the load actuator being used to simulate wind loads on the structure; At least one upper counterweight is axially movable and locked on the central rod, and the upper counterweight is used for preliminary adjustment of the center of gravity and moment of inertia of the device; At least one moment of inertia control mechanism is capable of moving and locking axially on the central rod. The moment of inertia control mechanism includes a drive mechanism and a weight adjustment mechanism. The drive mechanism is capable of driving the weight adjustment mechanism to move and lock along the vertical tangential direction of the axis of the central rod.

[0007] Optionally, the load actuator includes: The extender is slidably engaged with the central rod; A brushless motor is mounted on the extender via a first retainer; The fan blades are connected to the output shaft of the brushless motor.

[0008] Optionally, the load actuator further includes: A pressure sensor is fixedly mounted on the extender via a second retainer, and the first retainer is connected to the measuring end of the pressure sensor.

[0009] Optional, also includes: A connector is slidably engaged with the central rod, and the connector is connected to the moment of inertia control mechanism.

[0010] Optionally, the drive mechanism includes: slide rail; A slide table is slidably fitted on the slide rail, and the weight adjustment mechanism is provided on the slide table; A power unit is used to drive the slide table to slide along the slide rail.

[0011] Optionally, the weight adjustment mechanism includes: A fixed frame is connected to the slide table; A fixed flange is used to lock the counterweight disc in place, in conjunction with the fixed bracket.

[0012] Optionally, the power assembly includes: The stepper motor has an output shaft connected to a lead screw via a coupling, and the lead screw is engaged with the slide table for transmission.

[0013] Optionally, both ends of the lead screw have limit baffles.

[0014] Optionally, when there are multiple rotational inertia control mechanisms, they are arranged at equal intervals in the circumferential direction on the same plane.

[0015] Optionally, when there are multiple load actuators, they can respectively simulate wind loads in different directions on the structure.

[0016] The present invention discloses the following technical effects: This invention integrates a load actuator, an upper counterweight, and a moment of inertia control mechanism on the same central rod. By adjusting the position of the adjustable mechanism and its own weight through the sliding and locking upper counterweight and moment of inertia control mechanism, the mass distribution is dynamically adjusted to accurately match the target moment of inertia. This achieves physical-level collaborative simulation of wind load and moment of inertia, effectively compensating for dynamic response deviations caused by wind speed scaling limitations.

[0017] This invention features a compact structure and high integration, reducing the interference of the loading mechanism's self-weight on the model's center of gravity and inertia. It is applicable to various scaled-down models of marine structures and has strong versatility and adaptability. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the load actuator structure of the present invention; Figure 3 This is a schematic diagram of the rotational inertia control mechanism of the present invention; Figure 4 This is a cross-sectional view of the moment of inertia control mechanism of the present invention; Figure 5 This is a time-domain experimental result diagram from a specific embodiment of the present invention; Figure 6 This is a graph showing the results of frequency domain analysis in a specific embodiment of the present invention.

[0019] In the diagram: 1. Slide rail; 2. Coupling; 3. Extender; 4. Pressure sensor; 5. Center rod; 6. Upper counterweight; 7. Second fixture; 8. First fixture; 9. Brushless motor; 10. Fan blade; 11. Fixing frame; 12. Fixing flange; 13. Counterweight disc; 14. Limiting baffle; 15. Connector; 16. Lead screw; 17. Slide table; 18. Stepper motor. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Reference Figures 1 to 6 This invention provides a novel device for simulating wind load and rotational inertia of marine structures, comprising: The central rod 5 is used to connect to the moment of inertia measuring device, with the central rod 5 as the core spatial axis; At least one load actuator is capable of moving axially and locking on the central rod 5. The load actuator is used to simulate the wind load on the structure. At least one upper counterweight 6 is axially movable and locked on the central rod 5. The upper counterweight 6 is used to initially adjust the center of gravity and moment of inertia of the device. At least one moment of inertia control mechanism is capable of moving and locking along the axial direction on the central rod 5. The moment of inertia control mechanism includes a drive mechanism and a weight adjustment mechanism. The drive mechanism is capable of driving the weight adjustment mechanism to move and lock along the vertical tangential direction of the axis of the central rod 5.

[0023] The rotational inertia measuring device is connected via the central rod 5, achieving overall stability and measurement accuracy. The load actuator can move and lock along the axial direction, flexibly simulating wind loads at different heights and directions, improving the diversity and accuracy of the simulation. The upper counterweight 6 is used for initial adjustment of the device's center of gravity and inertia, ensuring the device's balance under static conditions. The rotational inertia control mechanism, through the coordinated action of the drive mechanism and the weight adjustment mechanism, achieves precise adjustment and locking of the rotational inertia, effectively compensating for the inertia mismatch caused by the self-weight of the loading mechanism, and improving the accuracy of the model's dynamic response under complex sea conditions.

[0024] In one embodiment of the present invention, the load actuator includes: Extender 3 is slidably engaged with center rod 5; The brushless motor 9 is mounted on the extender 3 via the first retainer 8; Fan blade 10 is connected to the output shaft of brushless motor 9.

[0025] The slidable engagement between the extender 3 and the central rod 5 enables flexible axial movement and positioning of the load actuator. The brushless motor 9 is securely mounted on the extender 3 via the first retainer 8, ensuring the stability and reliability of its operation. The fan blade 10 is connected to the output shaft of the brushless motor 9, enabling efficient reproduction of wind loads and improving the realism and dynamic response speed of the simulated wind field.

[0026] In one embodiment of the present invention, the load actuator further includes: Pressure sensor 4 is fixedly mounted on expander 3 by second fixture 7, and first fixture 8 is connected to the measuring end of pressure sensor 4.

[0027] Pressure sensor 4 is securely mounted on extender 3 via second fixture 7, enabling real-time monitoring of the wind load applied by the load actuator. First fixture 8 is connected to the measuring end of pressure sensor 4, ensuring the accuracy and real-time nature of the measurement data. This allows test personnel to adjust the parameters of the load actuator in a timely manner to achieve the best wind load simulation effect.

[0028] In one embodiment of the present invention, it further includes: Connector 15 is slidably engaged with center rod 5, and connector 15 is connected to rotational inertia control mechanism.

[0029] The slidable engagement between connector 15 and center rod 5 enables flexible axial movement and positioning of the rotational inertia control mechanism. Furthermore, regardless of the number of rotational inertia control mechanisms, the same height position of multiple rotational inertia control mechanisms can be adjusted simply by adjusting the position of connector 15.

[0030] In one embodiment of the present invention, the driving mechanism includes: Slide rail 1 is fixedly connected to connector 15; The slide table 17 is slidably fitted on the slide rail 1, and the slide table 17 is equipped with a weight adjustment mechanism. A power unit is used to drive the slide table 17 to slide along the slide rail 1.

[0031] The drive mechanism, through the sliding engagement of the slide rail 1 and the slide table 17, enables precise movement of the weight adjustment mechanism in the vertical tangential direction of the central rod 5. The power unit provides a stable driving force, ensuring smooth sliding of the slide table 17 along the slide rail 1. This design makes the adjustment of the moment of inertia more precise and controllable.

[0032] In one embodiment of the present invention, the weight adjustment mechanism includes: The fixed frame 11 is connected to the slide table 17; The fixed flange 12 cooperates with the fixed bracket 11 to lock the counterweight disc 13.

[0033] The weight adjustment mechanism, securely connected to the slide table 17 via the fixed frame 11, ensures the stability and safety of the counterweight disc 13 during sliding. The cooperation between the fixed flange 12 and the fixed frame 11 reliably locks the counterweight disc 13, preventing it from loosening or falling off during the test. This improves the overall safety and reliability of the device.

[0034] In one embodiment of the present invention, the power assembly includes: The stepper motor 18 has its output shaft connected to a lead screw 16 via a coupling 2. The lead screw 16 is driven by a slide table 17. The stepper motor 18 is fixedly mounted on the slide rail 1, and the lead screw 16 is rotatably mounted on the slide rail 1. The slide table 17 is provided with a nut that cooperates with the lead screw 16. The slide rail 1 is used to guide and limit the slide table 17 to prevent the slide table 17 from rotating when the lead screw 16 rotates, so that the slide table 17 can move and slide stably along the slide rail 1.

[0035] The power assembly uses a stepper motor 18 as the power source, connecting the lead screw 16 and the slide table 17 via a coupling 2, thus achieving precise transmission and positioning of the slide table 17. The stepper motor 18 features high precision and high reliability, ensuring the stability and accuracy of the slide table 17 during sliding. This improves the accuracy and efficiency of moment of inertia adjustment.

[0036] In one embodiment of the present invention, both ends of the lead screw 16 are equipped with limit baffles 14.

[0037] Limiting baffles 14 are provided at both ends of the lead screw 16, which effectively prevents the slide table 17 from overtraveling or derailing during the sliding process, thus improving the safety and reliability of the device.

[0038] In one embodiment of the present invention, when there are multiple moment of inertia control mechanisms, they are arranged circumferentially at equal intervals on the same plane. This enables the uniform distribution of the moment of inertia adjustment force, improving the overall stability and adjustment accuracy of the device. In this embodiment, there are four moment of inertia control mechanisms.

[0039] In one embodiment of the present invention, when multiple load actuators are used, wind loads in different directions acting on the structure are simulated separately. Wind loads in different directions acting on the structure, such as longitudinal wind and lateral wind, can be simulated separately. This design allows the device to more comprehensively reproduce the wind load environment of the structure under complex sea conditions, improving the realism and accuracy of the model test.

[0040] Furthermore, the rotational inertia control mechanism can automatically adjust the position of the slide 17 based on the comparison between the measurement results and the target rotational inertia value, thereby completing the adaptive adjustment of the rotational inertia. At the same time, it can record the slide position corresponding to the target rotational inertia value and store data for multiple different rotational inertia conditions, so that the rotational inertia can be quickly switched without going ashore after the model is launched into the water. This enables multiple rotational inertia conditions to be tested in one launch, significantly reducing the test preparation time.

[0041] Furthermore, the upper counterweight 6, the extender 3, and the connector 15 are all locked in position to the center rod 5 by screws.

[0042] How to use: First, a central rod 5 of appropriate length is selected as the main support based on the scale of the target offshore structure (such as a floating wind turbine). Multiple moment of inertia control mechanisms are reliably connected to the central axis of the central rod 5 via rod connectors 15, constructing a spatial framework. This framework is highly adjustable; test personnel can precisely adapt to platform models with different moments of inertia by replacing counterweight discs 13 of different weights or flexibly adjusting the axial position of the upper counterweight block 6 and the rod connector 15 on the central rod 5.

[0043] A central rod extender 3 is mounted on the central rod 5 and its position is fixed with fixing screws. A second fixture 7 is then installed on the extender. Subsequently, a pressure sensor 4 is embedded in the second fixture 7, and a first fixture 8 is installed at the end of the pressure sensor 4. Finally, the brushless motor 9 and fan blade 10 are installed in sequence. By adjusting the axial position of the extender 3 on the central rod 5, the equivalent force points and thrust characteristics at different heights of the superstructure can be accurately simulated. To verify the reliability of the device, a pulsating wind load experiment was conducted, with test wind speeds of 5.35 m / s (root mean square 0.64 m / s) and 6.35 m / s (root mean square 0.77 m / s). The time-domain results of the experiment are as follows: Figure 5 As shown; the results after normalization and frequency domain analysis of the original data are as follows. Figure 6 As shown.

[0044] After the device is installed on the platform model, to address the deviation in center of gravity and inertia caused by the self-weight of the loading mechanism, dynamic compensation is performed using an upper counterweight block 6 that can slide along the axial direction of the central rod 5 and a rotational inertia control mechanism. Based on theoretical calculations, the test personnel first slide the upper counterweight block 6 to a preset coordinate and lock it using fixing screws. Then, the central rod 5 is placed on the rotational inertia testing device to measure the rotational inertia. The rotational inertia control mechanism then automatically adjusts the device to achieve the required rotational inertia, effectively offsetting the mass effect of the load actuator and ensuring that the overall model's rotational inertia in degrees of freedom such as roll and pitch is physically aligned with the design target value. The preliminary calculation method (with the center of mass of connector 15 as the origin and the x-axis pointing towards the bow) is as follows: (1) The moment of inertia of roll required to be provided by the counterweight In the formula I xx-block The moment of inertia of the roll provided by the counterweight, I xx-total The total roll moment of inertia is the objective of this invention. Ixx-other This refers to the moment of inertia of roll caused by components other than the counterweight.

[0045] (2) The pitching moment of inertia that needs to be provided by the counterweight In the formula I yy-block The pitching moment of inertia provided by the counterweight, I yy-total I represents the total pitch inertia of the present invention. yy-other This refers to the pitching moment of inertia caused by components other than the counterweight.

[0046] (3) The moment of inertia of the bow roll that needs to be provided by the counterweight In the formula I zz-block The moment of inertia of the bow provided for the counterweight, Izz-total I represents the total bow roll inertia of the present invention. zz-other The moment of inertia of bow roll caused by components other than the counterweight.

[0047] (4) Position of each counterweight When performing position calculation, the position of the upper counterweight 6 is first calculated and locked, and then the rotational inertia control mechanism will automatically calculate the position of the counterweight disk 13 based on the currently measured rotational inertia.

[0048] In the formula L block I is the straight-line distance from the center of mass of a single counterweight disk 13 to the connector 15. block The moment of inertia provided by a single counterweight disk, M block This represents the weight of a single counterweight disc.

[0049] Automatic fine-tuning After the initial adjustment, the moment of inertia of the present invention will be measured again. The measured data will be compared with the target moment of inertia. If the target value is greater than the current value, the automatic control device will use the stepper motor 18 to control the slide 17 to move outward. If the target value is less than the current value, the automatic control device will use the stepper motor 18 to control the slide 17 to move inward. After completion, the moment of inertia will be measured again. This process will be repeated until the target moment of inertia is reached.

[0050] Versatile Applications Under Multiple Working Conditions: The entire device is fixed to the top of the marine structure platform model as an equivalent mechanical module. Thanks to its multi-axial inertia adjustment capabilities, this device exhibits exceptional versatility: when changing the lower floating body model (e.g., switching from a semi-submersible to a single-column platform), only the upper counterweight block 6 and counterweight disk 13 of different weights need to be replaced to quickly complete the secondary matching of dynamic characteristics. This eliminates the need for repeated processing of expensive scaled-down physical superstructures, significantly improving experimental efficiency.

[0051] This invention reproduces wind loads using a brushless motor 9 and fan blades 10, while utilizing an upper counterweight 6 that can slide and lock along the central rod 5 and a rotational inertia control mechanism to readjust the rotational inertia. This solves the problems of center of gravity deviation and inertia mismatch caused by the weight of the external loading mechanism during testing, and can realistically reproduce the motion response of the structure under the coupling of wind and waves.

[0052] This invention allows for easy adjustment of the position of the upper counterweight 6 to accommodate models of different scales and types of marine structures (such as semi-submersible, monopole, or TLP platforms). This universal modular design enables it to be used as a standard component in various pool tests, greatly improving the reusability of the equipment.

[0053] This invention can be directly installed on a model platform as an equivalent simulation unit of the superstructure, replacing the traditional physical scaled-down superstructure model that requires high-precision machining, has high manufacturing costs, and a long production cycle. By adopting a standardized and modular structural design, test personnel only need to determine the position and weight of the upper counterweight 6 based on the target moment of inertia and select the required mass of the counterweight disk 13 to complete the basic configuration of the inertia parameters. Based on this, the entire device is placed on the moment of inertia measuring device for measurement and automatic adjustment, achieving rapid and accurate balancing of the model's moment of inertia, avoiding repeated machining and manual adjustments. This not only significantly reduces model manufacturing and processing costs but also greatly shortens the model debugging and test preparation cycle, improving the overall efficiency and economy of water tank model testing.

[0054] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0055] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A novel device for simulating wind load and rotational inertia of marine structures, characterized in that, include: The center rod (5) is used to connect to the moment of inertia measuring device; At least one load actuator is capable of moving axially and locking on the central rod (5), the load actuator being used to simulate the wind load on the structure; At least one upper counterweight (6) is axially movable and locked on the central rod (5), and the upper counterweight (6) is used for preliminary adjustment of the center of gravity and moment of inertia of the device; At least one moment of inertia control mechanism is capable of moving and locking axially on the central rod (5). The moment of inertia control mechanism includes a drive mechanism and a weight adjustment mechanism. The drive mechanism is capable of driving the weight adjustment mechanism to move and lock along the vertical tangential direction of the axis of the central rod (5).

2. The novel wind load and rotational inertia co-simulation device for marine structures according to claim 1, characterized in that, The load actuator includes: The extender (3) is slidably engaged with the central rod (5); A brushless motor (9) is mounted on the extender (3) via a first retainer (8); The fan blade (10) is connected to the output shaft of the brushless motor (9).

3. The novel wind load and moment of inertia simulation device for marine structures according to claim 2, characterized in that, The load actuator further includes: The pressure sensor (4) is fixedly installed on the extender (3) by the second fixture (7), and the first fixture (8) is connected to the measuring end of the pressure sensor (4).

4. The novel wind load and rotational inertia co-simulation device for marine structures according to claim 1, characterized in that, Also includes: The connector (15) is slidably engaged with the central rod (5) and is connected to the moment of inertia control mechanism.

5. A novel device for simulating wind load and rotational inertia of marine structures according to claim 1, characterized in that, The drive mechanism includes: Slide rail (1); The slide table (17) is slidably fitted on the slide rail (1), and the weight adjustment mechanism is provided on the slide table (17); A power unit for driving the slide (17) to slide along the slide rail (1).

6. A novel device for simulating wind load and moment of inertia of marine structures according to claim 5, characterized in that, The weight adjustment mechanism includes: A fixed frame (11) is connected to the slide (17); The fixed flange (12) cooperates with the fixed frame (11) to lock the counterweight disc (13).

7. A novel device for simulating wind load and moment of inertia of marine structures according to claim 5, characterized in that, The power assembly includes: The stepper motor (18) has its output shaft connected to a lead screw (16) via a coupling (2), and the lead screw (16) is in transmission cooperation with the slide (17).

8. A novel device for simulating wind load and moment of inertia of marine structures according to claim 7, characterized in that, Both ends of the lead screw (16) have limit baffles (14).

9. A novel device for simulating wind load and moment of inertia of marine structures according to claim 1, characterized in that, When there are multiple rotational inertia control mechanisms, they are arranged at equal intervals in the circumferential direction on the same plane.

10. A novel device for simulating wind load and moment of inertia of marine structures according to claim 1, characterized in that, When there are multiple load actuators, they can simulate wind loads in different directions on the structure.

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