Riser Vibration Suppression-Energy-Saving System Based on Unpowered Propeller and Experimental Analysis Method

Abstract

This application relates to the field of marine oil and gas resource development and marine energy utilization technology, and discloses a riser vibration suppression-energy-extraction system based on a propeller-free system and its experimental analysis method. The experimental analysis method for the riser vibration suppression-energy-extraction system based on a propeller-free system includes: conducting a deep-sea vibration simulation experiment on a riser model using the riser vibration suppression-energy-extraction system based on a propeller-free system to obtain experimental strain data; performing a first correction on the experimental strain data based on the difference between the experimental ocean current and the actual ocean current; performing a second correction on the experimental strain data based on the boundary effects of the simulation experiment; and performing a third correction on the experimental strain data based on wave factors, suspended sediment and bubble factors, and attached material factors. Thus, through these three stages of correction of the experimental strain data, the experimental strain data can be made closer to the true value, thereby improving the accuracy of the simulation results.

Description

Technical Field

[0001] This application relates to the fields of marine oil and gas resource development and marine energy utilization, for example to a riser vibration suppression-energy-saving system based on a non-powered propeller and an experimental analysis method. Background Technology

[0002] Offshore risers are the sole conduit connecting subsea oil wells to surface oil platforms, playing a crucial role in offshore oil and gas resource development systems. Complex environmental factors such as waves and ocean currents can induce vortex-induced vibrations in risers, while gas-liquid two-phase flow within the riser can cause flow-induced vibrations. Under the combined influence of these factors, offshore risers are highly susceptible to fatigue damage or even failure, resulting in significant economic losses and severe damage to the marine ecosystem. Therefore, effectively suppressing the vibration of offshore risers is a key scientific challenge in solving the technical difficulties of offshore oil and gas resource development.

[0003] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0005] This disclosure provides a riser vibration suppression-energy-saving system based on a non-powered propeller and an experimental analysis method to improve the accuracy of simulation results.

[0006] In some embodiments, the experimental analysis method of the riser vibration suppression-energy-saving system based on a propeller-free system includes: a vibration simulation device for generating vibration; a riser model, partially located inside a water tank and with its top end connected to the vibration simulation device; an internal and external circulation system, the gas-liquid output end of which is connected to the bottom end of the riser model; and one or more flow disturbance devices disposed on the outer wall of the riser model. The experimental analysis method includes: conducting a deep-sea vibration simulation experiment on the riser model using the propeller-free system to obtain experimental strain data; performing a first correction on the experimental strain data based on the difference between the experimental ocean current and the actual ocean current; and performing a first correction on the experimental... Strain data are analyzed to determine the type of difference between experimental and actual ocean currents; the experimental strain data are corrected for the first time based on the type of difference; a flume numerical model including boundaries is constructed, and the flume numerical model is used to simulate the bounded vibration strain of the riser model under bounded conditions and the unbounded vibration strain under unbounded conditions; the field area of ​​the riser model is determined based on the shortest distance between the riser model and the boundary and the wavelength of the waves, and the experimental strain data is corrected for the second time based on the field area of ​​the riser model, the bounded vibration strain, and the unbounded vibration strain; correction coefficients are determined for wave factors, suspended sediment and bubble factors, and attached material factors, and the experimental strain data is corrected for the third time based on the correction coefficients.

[0007] In some embodiments, the riser vibration suppression-energy-saving system based on a non-powered propeller includes: a vibration simulation device for generating vibration; a riser model, partially located inside a water tank and with its top end connected to the vibration simulation device; an internal and external flow circulation system, the gas-liquid output end of which is connected to the bottom end of the riser model; one or more flow disturbance devices disposed on the outer wall of the riser model; and a power generation mechanism connected to the flow disturbance devices.

[0008] The riser vibration suppression-energy-saving system and experimental analysis method based on a non-powered propeller provided in this disclosure can achieve the following technical effects:

[0009] First, experimental strain data was obtained through a deep-sea vibration simulation experiment of a riser. Analysis of this data determined the type of difference between the actual ocean current and the real ocean current, leading to an initial correction of the strain data based on this difference. Then, considering the boundary effects of the simulation, the bounded vibration strain of the riser model under bounded constraints and the unbounded vibration strain under unbounded constraints were calculated using a flume numerical model. This data, combined with the field region where the riser model is located, resulted in a second correction of the strain data. In this way, by considering the differences between the experimental and actual ocean currents and the influence of the flume boundary on vibration in the simulation, the experimental strain data is corrected to more closely approximate actual conditions, thereby improving the accuracy of the simulation results. Correction coefficients are used to refine the data. The peak strain and vibrational energy level caused by extreme wave time are corrected by a correction factor. The effect of changes in the physical properties of the fluid medium on the overall vibration energy level is corrected by a correction factor. The impact of increased overall load due to changes in the geometric properties and surface characteristics of the riser model is corrected. Thus, by correcting the experimental strain data in three stages, the experimental strain data can be made closer to the true value. Meanwhile, ocean currents have a significant impact on the data; therefore, correcting the experimental strain data based on the difference between the experimental and actual ocean currents can further improve the accuracy of the data correction. Furthermore, differentiating the experimental strain data based on the type of difference between the experimental and actual ocean currents and the field area where the riser model is located can further improve the accuracy of the data correction, thereby improving the accuracy of the simulation results.

[0010] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0011] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0012] Figure 1 This is a schematic diagram of the structure of a riser vibration damping-energy system based on a non-powered propeller, which has a horizontally arranged Scottish yoke mechanism and a water tank, according to an embodiment of this disclosure.

[0013] Figure 2 This is a schematic diagram of the structure of a riser vibration damping-energy system based on a non-powered propeller, which has a horizontally arranged Scottish yoke mechanism and no water tank, according to an embodiment of this disclosure.

[0014] Figure 3 This is a structural schematic diagram of a riser vibration damping-energy system based on a non-powered propeller, where the Scottish yoke mechanism is vertically arranged and there is no water tank, according to an embodiment of this disclosure.

[0015] Figure 4 This is a schematic diagram of the structure of the turbulence device provided in the embodiments of this disclosure from a first perspective;

[0016] Figure 5 This is a structural schematic diagram of the turbulence device provided in the embodiments of this disclosure from a second perspective;

[0017] Figure 6 This is a schematic diagram of the magnet fixing box provided in an embodiment of this disclosure;

[0018] Figure 7 This is a schematic diagram of the riser model provided in the embodiments of this disclosure;

[0019] Figure 8 This is a schematic diagram of the structure of the sealing strip provided in the embodiments of this disclosure;

[0020] Figure 9 This is a schematic diagram of the horizontally arranged Scottish yoke mechanism provided in an embodiment of this disclosure;

[0021] Figure 10 This is a schematic diagram of the vertically arranged Scottish yoke mechanism provided in an embodiment of this disclosure;

[0022] Figure 11 This is a schematic diagram of the experimental analysis method of the riser vibration suppression-energy-saving system based on a non-powered propeller provided in the embodiments of this disclosure;

[0023] Figure 12 This disclosure provides an embodiment based on bounded vibration strain when the riser model is located in the near-field region. and unbounded vibration strain A schematic diagram of the method for second correction of experimental strain data;

[0024] Figure 13 This disclosure provides an embodiment based on bounded vibration strain when the riser model is located in the mid-field zone. and unbounded vibration strain A schematic diagram of the method for second correction of experimental strain data.

[0025] Figure label:

[0026] 10. Vibration simulation device; 11. Support device; 12. Bracket; 121. First slide groove; 122. Pulley; 13. Motor;

[0027] 20. Riser model; 21. Pipe section; 211. Power transmission transfer duct; 22. Oil pipeline; 23. Protective pipe; 24. Conductive contact; 25. Ball bearing groove; 26. Sealing strip; 261. Annular groove; 262. Annular protrusion; 263. Annular part; 264. Circular cut;

[0028] 30. Internal and external circulation system; 31. Water tank; 32. Hose; 33. Liquid pipeline; 331. Infusion pipe; 332. Liquid pump; 333. Liquid flow meter; 34. Gas pipeline; 341. Gas pipeline; 342. Gas pump; 343. Gas flow meter; 344. Gas check valve; 35. Three-way valve; 36. Flow pipeline;

[0029] 40. Flow disturbance device; 41. Positioning mechanism; 411. First sleeve; 412. First gear; 413. Ring; 414. Support arm; 42. Rotating mechanism; 421. Second sleeve; 422. Support leg; 423. Second gear; 424. Flow indicator; 43. Propeller mechanism; 431. Three sleeves; 432. Rotating shaft; 433. Propeller blade;

[0030] 50. Generating mechanism; 51. Permanent magnet; 52. Generating coil; 53. Through hole; 54. Magnet fixing box;

[0031] 60. Scottish yoke mechanism; 61. Slide bar; 611. Guide rail; 62. Connecting part; 621. Sliding groove; 63. Transmission part; 631. Disc; 632. Second sliding groove; 633. Sliding part; 634. Rotating part;

[0032] 70. Universal joint; 80. Water tank. Detailed Implementation

[0033] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0034] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0035] Unless otherwise stated, the term "multiple" means two or more.

[0036] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0037] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0038] The term "correspondence" can refer to an association or binding relationship. The correspondence between A and B means that there is an association or binding relationship between A and B.

[0039] Combination Figures 1 to 3 As shown, this disclosure provides a riser vibration suppression-energy-saving system based on a powerless propeller, including: a vibration simulation device 10, a riser model 20, an internal and external flow circulation system 30, one or more flow disturbance devices 40, and a power generation mechanism 50. Figure 1 As shown, the bottom of the vibration simulation device 10 is mounted on top of the water tank 80. Combined with... Figure 2 and Figure 3 As shown, the top of the riser model 20 is connected to the vibration simulation device 10, and a portion of it is located in the water tank 80. When the vibration simulation device 10 is activated, it generates vibration, which in turn causes the riser model 20 to perform swaying and heaving movements. The gas-liquid output end of the internal and external flow circulation system 30 is connected to the bottom end of the riser model 20 via a three-way valve 35, used to supply gas and liquid to the riser model 20, thereby simulating the working state of the riser model 20 transporting gas and liquid in the deep sea, and thus simulating the flow-induced vibration of the riser model 20 caused by the gas-liquid two-phase flow inside the pipe. One or more flow-disrupting devices 40 are installed on the outer wall of the riser model 20, wherein multiple flow-disrupting devices 40 are arranged sequentially at intervals along the axial direction of the riser model 20, and multiple flow-disrupting devices 40 are located underwater. A power generation mechanism 50 is connected to the flow-disrupting devices 40, used to convert the kinetic energy of the ocean current into electrical energy.

[0040] Combination Figures 4 to 6 As shown, the disturbance device 40 includes a positioning mechanism 41, a rotating mechanism 42, and a propeller mechanism 43. The positioning mechanism 41 is sleeved on the outer wall of the riser model 20 and fixed by fasteners. The rotating mechanism 42 is sleeved on the outer wall of the riser model 20 and located above the positioning mechanism 41, and is rotatably connected to the positioning mechanism 41. The propeller mechanism 43 is connected to the side of the rotating mechanism 42. When the ocean current flows over the surface of the riser model 20, the kinetic energy of the ocean current is converted into the kinetic energy of the propeller mechanism 43, driving the propeller mechanism 43 to perform circular motion. The propeller mechanism 43 can disrupt the flow pattern of the ocean current and generate convection in the opposite direction of the ocean current, thereby reducing the flow velocity and the probability of eddy shedding, reducing the amplitude and vibration frequency of the riser model 20, and achieving a vibration suppression effect. When the direction of the propeller blades in the propeller mechanism 43 is 180° with the direction of the ocean current in the horizontal plane, equilibrium is reached, and the propeller mechanism 43 stops rotating.

[0041] The riser vibration suppression-energy-saving system based on a non-powered propeller provided in this embodiment connects the top of the riser model 20 to the vibration simulation device 10 and the bottom to the gas-liquid output end of the internal and external flow circulation system 30. Vibration is generated by the vibration simulation device 10 to simulate the swaying and heaving motions of the riser model 20. Simultaneously, the internal and external flow circulation system 30 supplies gas and liquid into the riser model 20 to simulate the flow-induced vibration caused by the gas-liquid two-phase flow within the riser model 20 during gas-liquid transportation in the deep sea. This fully simulates the working state of the riser model 20 in the deep sea. One or more flow-disrupting devices 40 are installed on the outer wall of the riser model 20. Each flow-disrupting device 40 includes a positioning mechanism 41, a rotating mechanism 42, and a propeller mechanism 43. The positioning mechanism 41 is sleeved on the outer wall of the riser model 20 to fix the overall installation position of the flow-disrupting device 40. The rotating mechanism 42 is fitted onto the outer wall of the riser model 20 and rotatably connected to the positioning mechanism 41, while the propeller mechanism 43 is connected to the side of the rotating mechanism 42. When the ocean current flows over the surface of the riser model 20, it drives the propeller mechanism 43 to perform circular motion, converting the kinetic energy of the ocean current into the kinetic energy of the propeller mechanism 43. The propeller mechanism 43 can disrupt the flow pattern of the ocean current and generate convection in the opposite direction of the ocean current, thereby reducing the flow velocity and the probability of eddy shedding, reducing the amplitude and vibration frequency of the riser model 20, and achieving a vibration suppression effect. The power generation mechanism 50 is connected to the flow disturbance device 40. While the flow disturbance device 40 suppresses vibration, the power generation mechanism 50 can also convert the kinetic energy of the ocean current into electrical energy, achieving an energy recovery effect.

[0042] Optionally, see again Figure 4 The positioning mechanism 41 includes a first sleeve 411, a first gear 412, and a ring 413. The first sleeve 411 is fitted and fixed to the outer wall of the riser model 20, and a support arm 414 is provided on the first sleeve 411. Optionally, the first sleeve 411 is formed by the mating of two semi-circular structures, and connecting ears are provided at both ends of the two semi-circular structures. Bolts are used as fasteners to connect the connecting ears of the two semi-circular structures together, thereby forming a complete first sleeve 411. The connecting ears protrude outward relative to the cylindrical shape of the first sleeve 411, thereby forming the support arm 414. The first gear 412 is fitted on the outer wall of the riser model 20 and is connected to the top of the first sleeve 411. The ring 413 is fitted on the outside of the first sleeve 411, and the support arm 414 is supported at the bottom of the ring 413, but the ring 413 and the support arm 414 are not connected. A connector is provided on the ring 413, and the positioning mechanism 41 is connected to the rotating mechanism 42 through the connector. Meanwhile, the positioning mechanism 41 meshes with the rotating mechanism 42 through the first gear 412, thereby forming a rotary connection. In this way, the positioning mechanism 41 positions the rotational position of the rotating mechanism 42 and provides support when the rotating mechanism 42 rotates.

[0043] Optionally, see [link to relevant documentation] Figure 4 The rotating mechanism 42 includes a second sleeve 421, a flow indicator 424, multiple supports 422, and multiple second gears 423. The second sleeve 421 is fitted onto the outer wall of the riser model 20 and is located above the first sleeve 411. Multiple supports 422 are evenly connected to the bottom of the second sleeve 421 along its circumference. Each support 422 is cylindrical, with its top end face connected to the bottom of the second sleeve 421, and has a threaded hole along its axial direction. The number of second gears 423 is equal to the number of supports 422, and they correspond one-to-one. Each second gear 423 is fitted onto the outer wall of its corresponding support 422 and can rotate freely around the support 422. The size of each second gear 423 is smaller than that of the first gear 412, and each second gear 423 is located circumferentially to the first gear 412 and meshes with it, thereby achieving a rotational connection between the rotating mechanism 42 and the positioning mechanism 41. The flow vane 424 is connected to the top of the second sleeve 421 and extends horizontally away from the propeller mechanism 43. The straight line along the horizontal length of the flow vane 424 is perpendicular to the rotation plane of the propeller mechanism 43. Thus, when the ocean current flows past the flow vane 424, the flow vane 424 will tend to move from its equilibrium state, thereby transmitting a force signal to the entire vibration suppression and energy-saving system. Due to the geometric symmetry of the entire flow disturbance device 40, after receiving the force signal transmitted by the flow vane 424, it will rotate around the riser model 20 until it reaches the equilibrium position. At this time, the rotation plane of the unpowered propeller mechanism is perpendicular to the line of ocean current velocity, thereby achieving the maximum effect of vibration suppression and energy saving.

[0044] Optionally, see again Figure 5 The propeller mechanism 43 includes a third sleeve 431, a rotating shaft 432, and multiple blades 433. The third sleeve 431 is vertically positioned, with both end faces facing horizontally. One end face of the third sleeve 431 is closed, and the other is open. The closed end face is connected to the side of the rotating mechanism 42, i.e., to the circumferential outer wall of the second sleeve 421. The rotating shaft 432 is disposed inside the third sleeve 431 and coaxially with it. The first end of the rotating shaft 432 is rotatably connected to the closed end. Multiple blades 433 are evenly connected to the outer wall of the rotating shaft 432 along its circumference, and the blades 433 are located outside the third sleeve 431 to be driven by ocean currents.

[0045] Optionally, combined Figure 5 and Figure 6As shown, the power generation mechanism 50 includes: a permanent magnet 51, a power generation coil 52, and a bundled cable. The permanent magnet 51 is disposed on the outer wall of the rotating shaft 432 and rotates together with the rotating shaft 432. The power generation coil 52 is disposed on the inner wall of the third sleeve 431 and its position is fixed. The riser model 20 has a sandwich structure, and the bundled cable is disposed in the sandwich structure. Figure 4 and Figure 5 As shown, the closed end face of the third sleeve 431 and the circumferential wall of the second sleeve 421 are provided with corresponding through holes 53. Combined with... Figure 7 As shown, the riser model 20 has a power transmission transfer channel 211 corresponding to the through hole 53 on its wall. One end of the bundled cable passes through the power transmission transfer channel 211 and the through hole 53 and is connected to the power generation coil 52, while the other end is connected to external electrical equipment. When the ocean current flows over the surface of the riser model 20, the blade 433 drives the rotating shaft 432 to rotate, and the permanent magnet 51 also rotates accordingly. The magnetic field lines excited by the permanent magnet 51 are cut by the power generation coil 52 during the rotation. According to the law of magnetic induction, an induced current will be generated inside the power generation coil 52. The current is transmitted to the electrical equipment through the bundled cable, realizing the effective development and utilization of renewable energy.

[0046] Optionally, see again Figure 6 Multiple permanent magnets 51 are present, and multiple magnet fixing boxes 54, matching the size of the permanent magnets 51, are uniformly welded to the outer wall of the rotating shaft 432. The permanent magnets 51 are embedded in the corresponding magnet fixing boxes 54. The power generation coil 52 is uniformly wound around the inner wall of the third sleeve 431. This improves the power generation efficiency.

[0047] Optionally, see again Figure 7 The riser model 20 includes multiple pipe sections 21. Two adjacent pipe sections 21 are rotatably connected. Each pipe section 21 includes an oil pipeline 22, a protective pipe 23, and conductive contacts 24. The oil pipeline 22 is cast from steel and is used for long-distance transportation of subsea oil and gas resources. The protective pipe 23 is made of CFRP composite material and is used to protect the internal oil pipeline 22 and the bundled cables. The protective pipe 23 is fitted over the outside of the oil pipeline 22, forming a double-layered pipe body with a central cavity in the riser model 20. Conductive contacts 24 are distributed at the top and bottom of the cavity, thereby sealing both ends of the cavity. The bundled cables are distributed within the cavity, and adjacent pipe sections 21 are connected via conductive contacts 24, thus connecting the bundled cables in each pipe section 21 to transmit the converted electrical energy to the power-consuming equipment.

[0048] Optionally, the power transfer channel 211 on the riser model 20 is formed on the protective pipe 23. Multiple flow-disrupting devices 40 correspond one-to-one with multiple pipe sections 21 and are fitted onto the outer wall of the corresponding pipe section 21 via a first sleeve 411. Thus, the power generation coil 52 of each flow-disrupting device 40 passes through the power transfer channel 211 on the corresponding pipe section 21 and is connected to the bundled cable within the corresponding pipe section 21.

[0049] Optionally, the location where the turbulence device 40 is installed can be in the form of a multi-section pipe 21, while the part where the turbulence device 40 is not installed can be a single pipe.

[0050] Optionally, the upper and lower ends of each pipe section 21 are assembled by ball bearing grooves 25, and the rotating propeller mechanism 43 drives the second sleeve 421 to rotate, thereby driving the corresponding pipe section 21 to rotate together.

[0051] Optionally, see Figure 8 Sealing strips 26 are provided on both end faces of pipe segment 21 to ensure a sealing effect when pipe segment 21 rotates. Specifically, the sealing strips 26 are annular. One sealing strip 26 has an annular groove 261 on its annular surface, and the other sealing strip 26 has an annular protrusion 262 on its annular surface. When two pipe segments 21 are joined, the annular protrusion 262 of the sealing strip 26 at one end of one pipe segment 21 embeds into the annular groove 261 of the sealing strip 26 at one end of the other pipe segment 21, thereby achieving a sealing and waterproof effect. An annular portion 263 extends radially towards the center of the inner wall of the sealing strip 26. The annular portion 263 has a circular cutout 264 for placing ball bearings, which can fix the position of the ball bearings without restricting their rolling motion.

[0052] Optionally, see again Figure 2 and Figure 3 The vibration simulation device 10 includes a support device 11, brackets 12, a motor 13, and a Scottish yoke mechanism 60. The support device 11 is a frame structure formed by connecting multiple rods and plates, providing mounting positions for other components. There are multiple brackets 12, one of which is located at the top of the support device 11 and serves to limit the vertical sliding of the Scottish yoke mechanism 60. The remaining brackets 12 are sequentially arranged at the same height along the horizontal direction on the support device 11, serving to limit the horizontal sliding of the Scottish yoke mechanism 60.

[0053] See Figure 3 When it is necessary to simulate the vertical pipe model 20 to perform helical motion at a sinusoidal velocity: the motor 13 is connected to the support device 11, and the power output shaft of the motor 13 is in a horizontal state. The Scottish yoke mechanism 60 is slidably connected to the bracket 12 located at the top of the support device 11 along the vertical direction.

[0054] See Figure 2 When it is necessary to simulate the riser model 20 oscillating at a sinusoidal velocity: the motor 13 is connected to the support device 11, and the power output shaft of the motor 13 is in a vertical state. The Scottish yoke mechanism 60 is slidably connected along the horizontal direction to each bracket 12 arranged along the horizontal direction of the support device 11.

[0055] The Scottish yoke mechanism 60 has a power input section and a power output section. Its power input section is connected to the power output shaft of the motor 13, and its power output section is connected to the top of the riser model 20 via a universal joint 70. When the Scottish yoke mechanism 60 is set vertically, it can convert the rotational motion of the motor 13 into linear motion, thereby driving the riser model 20 to reciprocate up and down, performing a standard sinusoidal oscillating motion. When the Scottish yoke mechanism 60 is set horizontally, it can convert the rotational motion of the motor 13 into linear motion, thereby driving the riser model 20 to reciprocate left and right, performing a standard sinusoidal oscillating motion.

[0056] Optionally, riser model 20 is made of PMMA acrylic tube.

[0057] Optionally, combined Figure 2 , Figure 3 , Figure 9 and Figure 10 The Scottish yoke mechanism 60 includes: a slide bar 61, a connecting part 62, and a transmission part 63. See also... Figure 2 and Figure 3 The bracket 12 has a first sliding groove 121 along its own setting direction (vertical or horizontal). See also Figure 9 and Figure 10 A guide rail 611 is provided on one side of the slide rod 61, and the guide rail 611 is arranged along the length direction of the first slide groove 121. A pulley 122 is provided in the first slide groove 121, and the pulley 122 is slidably embedded in the first slide groove 121. The side of the connecting part 62 is connected to the end of the slide rod 61. Optionally, there are two slide rods 61, and the ends of the two slide rods 61 are respectively connected to the opposite sides of the connecting part 62. At least one slide rod 61 is slidably embedded in the first slide groove 121 via the guide rail 611. For example, when the Scottish yoke mechanism 60 is arranged in a vertical direction, the ends of the two slide rods 61 are respectively connected to the upper and lower sides of the connecting part 62 (relative to the upper and lower sides). Figure 10 In this case, the upper slide bar 61 is slidably embedded in the first slide groove 121. When the Scottish yoke mechanism 60 is arranged in the horizontal direction, the ends of the two slide bars 61 are respectively connected to the left and right sides of the connecting part 62 (relative to the horizontal direction). Figure 9 In other words, combined Figure 2As shown, the slide bar 61 on the left is slidably embedded in the first slide groove 121 located between the leftmost bracket 12 and the middle bracket 12, and the slide bar 61 on the right is slidably embedded in the first slide groove 121 located between the rightmost bracket 12. The length of the slide bar 61 can be selected according to actual needs.

[0058] See Figure 9 and Figure 10 The connecting part 62 is provided with a sliding groove 621, and the length direction of the sliding groove 621 is perpendicular to the sliding direction of the slide rod 61, that is, the length direction of the slide rod 61. The first side of the transmission part 63 is connected to the power output shaft of the motor 13, and the second side of the transmission part 63 is provided with a power output end. The first side and the second side of the transmission part 63 are opposite sides, and the first side of the transmission part 63 is the side facing the power output shaft of the motor 13. The power output end of the transmission part 63 is rotatably embedded in the sliding groove 621, thereby forming a groove mechanical connection with the sliding groove 621.

[0059] After motor 13 starts, it drives transmission part 63 to rotate via its own power output shaft, and the power output end of transmission part 63 also rotates accordingly. Due to the restriction of sliding groove 621, connecting part 62 reciprocates in a straight line, thereby driving slide rod 61 to reciprocate in a straight line. Therefore, slide rod 61 serves as the final power output end of Scottish yoke mechanism 60. Riser model 20 is in a vertically suspended state and is connected to a slide rod 61 via universal joint 70. For example, see Figure 10 When the Scottish yoke mechanism 60 is positioned vertically, the top end of the riser model 20 is connected to the bottom end of the slide bar 61 located below via a universal joint 70. See also Figure 9 When the Scottish yoke mechanism 60 is set in the horizontal direction, the riser model 20 is connected to the bottom surface of the slide bar 61 located on the right side via the universal joint 70.

[0060] See you again Figure 9 and Figure 10 Optionally, the transmission unit 63 includes a disc 631 and a sliding knob assembly. The first disc of the disc 631 faces the power output shaft of the motor 13 and is drively connected to the power output shaft of the motor 13. A second groove 632 is provided radially on the second disc surface of the disc 631. The sliding knob assembly, serving as the power output end of the transmission unit 63, is embedded in the second groove 632 on one side and rotatably embedded in the sliding slot opening 621 on the other side. Thus, the disc 631 rotates under the drive of the motor 13 and transmits force to the connecting part 62 through the sliding knob assembly, thereby driving the connecting part 62 and the slide rod 61 to perform linear reciprocating motion.

[0061] See you again Figure 9 and Figure 10Optionally, the sliding knob assembly includes a sliding part 633 and a rotating part 634. The sliding part 633 is cubic and is embedded in the second slide groove 632, and can slide along the second slide groove 632. When the sliding part 633 slides to a preset position, it is fixed in the preset position by fasteners, such as pins, bolts, etc. The rotating part 634 is cylindrical and is connected to the sliding part 633 and rotatably embedded in the sliding groove opening 621. By adjusting the position of the sliding part 633 in the second slide groove 632, the length of the lever arm can be changed, thereby adjusting the swing amplitude of the connecting part 62 to simulate different degrees of vibration.

[0062] Optionally, the upper end of the universal joint 70 is fixed to the slide rod 61 by threads, and the lower end is connected to the riser model 20 by sealant.

[0063] Optionally, see again Figure 2 and Figure 3 The internal and external circulation system 30 includes: a water tank 31, a gas tank (not shown in the figure), a liquid pipeline 33, and a gas pipeline 34. The water tank 31 and the gas tank are located outside the water tank 80, while at least a portion of the liquid pipeline 33 and the gas pipeline 34 are located inside the water tank 80. One end of the liquid pipeline 33 is connected to the water tank 31, and the other end is connected to the first inlet of a three-way valve 35. One end of the gas pipeline 34 is connected to the gas tank, and the other end is connected to the second inlet of the three-way valve 35. The outlet of the three-way valve 35 is connected to the first end of a conveying pipeline 36. The conveying pipeline 36 is horizontally positioned, while the riser model 20 is vertically positioned; therefore, the second end of the conveying pipeline 36 is connected to the bottom end of the riser model 20 via a flexible hose 32.

[0064] Optionally, the liquid pipeline 33 includes: a delivery pipe 331, a liquid pump 332, and a liquid flow meter 333. One end of the delivery pipe 331 is connected to the water tank 31, and the other end is connected to the first inlet of the three-way valve 35. The liquid pump 332 and the liquid flow meter 333 are connected to the delivery pipe 331.

[0065] Optionally, the gas pipeline 34 includes a gas delivery pipe 341, a gas pump 342, and a gas flow meter 343. One end of the gas delivery pipe 341 is connected to a gas tank, and the other end is connected to the second inlet of a three-way valve 35. The gas pump 342 and the gas flow meter 343 are connected to the gas delivery pipe 341. After the gas and liquid are delivered to their corresponding pipelines by the gas pump 342 and the liquid pump 332, they are mixed by the three-way valve 35 and flow into the delivery pipeline 36, and then flow into the riser model 20 through the hose 32, thereby simulating the gas-liquid two-phase flow state in actual engineering. A gas check valve 344 is installed on the gas delivery pipe 341 to prevent the liquid density from being too high, which would prevent the gas from flowing into the delivery pipeline 36. The liquid flow meter 333 and the gas flow meter 343 are used to monitor the fluid flow rate.

[0066] Based on the aforementioned riser vibration suppression-energy-saving system based on a non-powered propeller, combined with Figure 11 As shown, this embodiment provides an experimental analysis method for a riser vibration suppression-energy-saving system based on a non-powered propeller, including:

[0067] S101, using a riser vibration suppression-energy-saving system based on a non-powered propeller, a deep-sea vibration simulation experiment was conducted on the riser model to obtain experimental strain data;

[0068] S102, Based on the difference between the experimental ocean current and the actual ocean current, the experimental strain data is corrected for the first time: the experimental strain data is analyzed to determine the type of difference between the experimental ocean current and the actual ocean current; the experimental strain data is corrected for the first time based on the type of difference.

[0069] S103. Construct a water tank numerical model including the boundary, and use the water tank numerical model to simulate the bounded vibration strain of the riser model under the boundary and the unbounded vibration strain under the unbounded boundary. Determine the field area of ​​the riser model based on the shortest distance between the riser model and the boundary and the wavelength of the wave, and make a second correction to the experimental strain data based on the field area of ​​the riser model, the bounded vibration strain and the unbounded vibration strain.

[0070] S104, determine the correction coefficients corresponding to wave factors, suspended sediment and bubble factors and attachment factors respectively, and perform a third correction on the experimental strain data based on the correction coefficients.

[0071] A riser vibration damping-energy-saving system based on a non-powered propeller was used to simulate the vibration experienced by the riser in deep sea. The parameters of the riser model and the simulation parameters for various operating conditions are shown in the following tables:

[0072]

[0073] 1. The simulation parameters for the vortex-induced vibration of a deep-sea riser under ocean currents are as follows:

[0074]

[0075] 2. The simulation parameters for the vibration response of a deep-sea riser oscillating in still water are:

[0076]

[0077] 3. The simulation parameters of the vibration response of the deep-sea riser under the coupled action of heave motion and ocean current are as follows:

[0078]

[0079] 4. The simulation parameters for the vibration response of a deep-sea riser undergoing oscillation motion in still water are:

[0080]

[0081] 5. The simulation parameters for the vibration response of the deep-sea riser under the coupled action of sway motion and ocean current are as follows:

[0082]

[0083] All five operating conditions were compared using bare riser models and riser models with turbulence suppression and energy generation systems. The vibration suppression effect of the riser vibration suppression and energy generation system under different environmental conditions such as ocean currents, heave, sway, and the combined effect of heave and ocean currents was analyzed through the comparative experiments.

[0084] After the experiment, experimental strain data for the riser model were obtained. However, there will inevitably be deviations between the experimental data and the actual data. Therefore, the experimental data was processed to make it closer to the actual data.

[0085] First, based on the differences between the experimental and actual ocean currents, the experimental strain data were corrected for the first time. Specifically, this included: adjusting the experimental strain data... Analysis was conducted to determine the types of differences between the experimental and actual ocean currents. These differences primarily included two types: differences in energy levels and missing frequency structure and nonlinearity. Appropriate correction schemes were matched based on the type of difference, and the experimental strain data underwent initial correction.

[0086] Then, based on the boundary effects of the simulation experiment, a second correction is made to the experimental strain data after the first correction. Specifically, this includes constructing a 1:1 numerical model of the water tank, including its boundaries, in finite element software, mirroring the physical simulation. The wave-generating signal from the physical simulation is then reproduced within the water tank numerical model, and the bounded vibration strain of the riser model under this environment is calculated. In the same water tank numerical model, open sea conditions were simulated using the same wave-generating signal, and the unbounded vibration strain of the riser model under this environment (without boundary disturbances) was calculated. Then, the field region where the riser model is located is determined based on the boundary between the riser model and the water tank. Optionally, the field region includes a near-field region, a mid-field region, and a negligible region. The negligible region indicates that the riser model is far from the water tank boundary, and the error caused by the boundary to the experimental data is negligible. Therefore, when the riser model is located in the near-field or mid-field region, the bounded vibration strain is used as the basis for determining the field region. and unbounded vibration strain A suitable correction scheme is matched, and the experimental strain data that have been corrected once are corrected a second time.

[0087] The wave conditions in real ocean environments are complex, and breaking waves and extreme waves (distorted waves) are difficult to accurately reproduce in simulation experiments. However, wave breaking and distorted waves generate enormous, nonlinear impact loads, significantly increasing the dynamic response of the riser model; these are high-intensity, transient effects. Suspended sediments in the ocean increase the apparent density and viscosity of the fluid, thus slightly increasing drag and added mass. Bubbles significantly reduce the local density of the fluid, thereby reducing added mass. The mixing effect of bubble-driven two-phase flow can generally reduce the overall hydrodynamic load. The ocean is also full of plankton and attached organisms, which increase the riser model diameter, directly increasing wave forces, and also increase pipe roughness, significantly increasing the drag coefficient. These factors all affect the accuracy of experimental data. Therefore, determining the correction factors corresponding to wave factors is crucial. Correction coefficients for suspended sediment bubble factors Correction coefficients corresponding to the attachment factor The experimental strain data are then corrected a third time based on these correction factors.

[0088] The experimental analysis method for the vibration characteristics of deep-sea risers provided in this disclosure first obtains experimental strain data through a deep-sea vibration simulation experiment of the riser. Analysis of the experimental strain data determines the type of difference between the actual ocean current and the real ocean current, and then the experimental strain data is corrected based on this type of difference. Next, considering the boundary effects of the simulation experiment, the bounded vibration strain of the riser model under bounded constraints and the unbounded vibration strain under unbounded constraints are calculated using a flume numerical model. Combined with the field area where the riser model is located, the experimental strain data is corrected a second time. In this way, by considering the difference between the experimental and actual ocean currents and the influence of the flume boundary on vibration in the simulation experiment, the experimental strain data is corrected to be closer to the actual situation, thereby improving the accuracy of the simulation results. Correction coefficients are used to further refine the data. The peak strain and vibrational energy level caused by extreme wave time are corrected by a correction factor. The effect of changes in the physical properties of the fluid medium on the overall vibration energy level is corrected by a correction factor. The impact of increased overall load due to changes in the geometric properties and surface characteristics of the riser model is corrected. Thus, by correcting the experimental strain data in three stages, the experimental strain data can be made closer to the true value. Meanwhile, ocean currents have a significant impact on the data; therefore, correcting the experimental strain data based on the difference between the experimental and actual ocean currents can further improve the accuracy of the data correction. Furthermore, differentiating the experimental strain data based on the type of difference between the experimental and actual ocean currents and the field area where the riser model is located can further improve the accuracy of the data correction, thereby improving the accuracy of the simulation results.

[0089] Optionally, the experimental strain data can be analyzed to determine the types of differences between the experimental and actual ocean currents, including:

[0090] Numerical simulation was used to calculate the target strain data generated by the riser model under the same sea conditions.

[0091] Based on the experimental strain data and the target strain data, calculate the root mean square of the target strain data and the root mean square of the experimental strain data, respectively.

[0092] When the root mean square of the experimental strain data is less than the preset order of magnitude of the root mean square of the target strain data, the difference type is determined to be an energy level difference.

[0093] When the higher-order harmonics in the experimental strain data are less than the preset value, the difference type is determined to be frequency structure and nonlinearity deficiency.

[0094] Through data simulation, the target strain data that the riser model should produce under the same sea conditions as the simulation experiment are calculated. This was used as a correction benchmark. Based on experimental strain data... Calculate the root mean square of experimental strain data Based on target strain data Calculate the root mean square of the target strain data .if Much smaller than If the root mean square of the experimental strain data is less than the preset order of magnitude of the root mean square of the target strain data, then the difference between the experimental ocean current and the actual ocean current is determined to be an energy level difference.

[0095] Analyzing the experimental strain data, if the spectrum is pure and the higher-order harmonics are less than the preset value, the difference between the experimental ocean current and the actual ocean current is determined to be frequency structure and nonlinearity deficiency. In this way, by analyzing the experimental strain data, the type of difference between the experimental ocean current and the actual ocean current can be determined so as to accurately match the correction scheme and improve the accuracy of the data.

[0096] Optionally, the experimental strain data are first corrected according to the type of difference, including:

[0097] When the difference type is energy level difference, the scaling factor is calculated based on the root mean square of the target strain data and the root mean square of the experimental strain data.

[0098] The product of the scaling factor and the experimental strain data is used as the first corrected data.

[0099] If the difference between the experimental and actual ocean currents is of energy level, it indicates that the overall root mean square strain value obtained from the simulation experiment is much lower than the theoretical expectation or the prototype observation value. Therefore, when correcting the data, the scaling factor is calculated according to formula (1) based on the root mean square of the target strain data and the root mean square of the experimental strain data. :

[0100] (1)

[0101] Based on scaling factor and experimental strain data Calculate the corrected data according to formula (2). :

[0102] (2)

[0103] Thus, the corrected Strictly equal to This ensures consistency with actual or theoretical expectations on the energy scale, effectively elevating experimental data to the energy levels required for practical engineering or theory. Simultaneously, it maintains the original characteristics of the vibration signal without altering its frequency components, phase relationships, or waveform characteristics; only the amplitude is uniformly scaled.

[0104] Optionally, the experimental strain data are first corrected according to the type of difference, including:

[0105] When the discrepancy type is frequency structure and nonlinearity absence, advanced and simplified numerical models are performed using the same wave parameters to obtain strain data from the advanced numerical model. And simplified numerical model strain data .

[0106] Based on advanced numerical model strain data And simplified numerical model strain data Model training is performed to obtain advanced numerical model strain data. And simplified numerical model strain data The mapping relationship.

[0107] Based on advanced numerical model strain data And simplified numerical model strain data The mapping relationship is used to determine the first corrected data corresponding to the experimental strain data.

[0108] If the difference between experimental and actual ocean currents is characterized by frequency structure and nonlinearity loss, it indicates that the strain power spectral density plot shows peaks only at a few simple frequencies, lacking higher-order harmonics and low-frequency slow-drift oscillation responses. Therefore, when correcting the data, first use the same wave parameters to perform advanced and simplified numerical models, obtaining the advanced numerical model strain data respectively. And simplified numerical model strain data Training a model to learn and The mapping relationship is used to apply this model to experimental strain data. Data output by the model This is the data after the first correction.

[0109] This effectively compensates for the limitations of laboratory ocean current simulations in reproducing complex frequency structures and nonlinear dynamic characteristics. Avoiding biases that may arise from simple scaling, it uses intelligent learning to precisely add key nonlinear response features present in the actual ocean environment, such as higher-order harmonics and low-frequency slow-drift oscillations, to the experimental data. This makes the amplitude of the corrected experimental strain data closer to reality.

[0110] Optionally, based on the shortest distance between the riser model and the tank boundary. With the wavelength of the wave Determine the site area where the riser model is located. If Then the riser model is determined to be in the near-field region. If Then the riser model is determined to be in the midfield zone. If If so, the riser model is determined to be in the negligible region.

[0111] Optionally, combined Figure 12 As shown, based on bounded vibration strain and unbounded vibration strain The experimental strain data were corrected a second time, including:

[0112] S1201, when the riser model is located in the near-field region, regarding the bounded vibration strain and unbounded vibration strain Performing a Fourier transform yields the distribution of vibrational energy of bounded vibrational strain at different frequencies. Distribution of vibrational energy at different frequencies of unbounded vibrational strain ;

[0113] S1202, based on the distribution of vibration energy at different frequencies of bounded vibration strain. Distribution of vibrational energy at different frequencies of unbounded vibrational strain Calculate the frequency domain correction factor;

[0114] S1203, the data after the first correction Perform a Fourier transform and multiply it by the frequency domain correction factor;

[0115] S1204 performs an inverse Fourier transform on the result of the multiplication, and the result of the transform is used as the data after the second correction.

[0116] When the riser model is located in the near-field region, the reflected waves and incident waves at the tank boundary will produce complex interference phenomena. This interference has different effects on wave components of different frequencies, causing the experimentally measured vibration strain to be amplified at some frequencies and suppressed at others, distorting the true frequency response characteristics. Bounded and unbounded data originate from the same excitation, and their differences are entirely caused by boundary effects.

[0117] Therefore, in this case, the bounded vibration strain and unbounded vibration strain Performing a Fourier transform yields the distribution of vibrational energy of bounded vibrational strain at different frequencies. Distribution of vibrational energy at different frequencies of unbounded vibrational strain This allows for the identification of the main frequencies, locking intervals, and higher-order harmonic components of vortex-induced vibrations.

[0118] according to and The frequency domain correction factor is calculated according to formula (3). :

[0119] (3)

[0120] The data after the first correction Perform a Fourier transform and compare it with the frequency domain correction factor. Multiply. Perform an inverse Fourier transform on the result of the multiplication, and use the result as the data after the second correction. As shown in formula (4):

[0121] (4)

[0122] Thus, when the riser model is in the near-field region, the vibration waveform of the structure in the time domain is decomposed into sinusoidal components of different frequencies by performing Fourier transforms on the bounded vibration strain and unbounded vibration. Then, based on the ratio of the transform results, a frequency domain correction factor is obtained. This frequency domain correction factor is used to further correct the data after the first correction, thereby improving the accuracy of the experimental data.

[0123] Optionally, combined Figure 13 As shown, based on bounded vibration strain and unbounded vibration strain The experimental strain data were corrected a second time, including:

[0124] S1301, based on bounded vibration strain, when the riser model is located in the mid-field region. and unbounded vibration strain Calculate the overall energy level scaling factor;

[0125] S1302, adjust the overall energy level scaling factor with the data after the first correction. The product of these two values ​​is used as the second revised data.

[0126] If the riser model is located in the mid-field zone, then it is based on bounded vibration strain. and unbounded vibration strain The overall energy level scaling factor is calculated according to formula (5). :

[0127] (5)

[0128] in, The root mean square value represents the strain value of unbounded vibration. It represents the root mean square value of the bounded vibration strain.

[0129] Scaling factor of the overall energy level Compared with the data after the first correction The product of these two values ​​is used as the data after the second correction. As shown in formula (6):

[0130] (6)

[0131] This can reduce the errors caused by boundary effects in experimental and actual risers.

[0132] Optionally, determine the correction coefficients corresponding to the wave factors, including:

[0133] Vibration simulations were performed using a high-order nonlinear numerical wave pool that incorporates wave breaking and distorted wave models.

[0134] Obtain the first vibration strain under normal irregular wave conditions and the second vibration strain including extreme wave conditions .

[0135] The first vibration strain corresponding root mean square With the second vibration strain corresponding root mean square The ratio of is used as the correction coefficient corresponding to the wave factor.

[0136] Determining the correction factor At that time, a high-order nonlinear numerical wave pool model incorporating a wave-breaking deformed wave model was used for simulation to obtain the first vibration strain of the riser model under the "ordinary irregular wave only" condition. and the second vibration strain under the "including extreme wave" condition And calculate the first vibration strain respectively. Second vibration strain corresponding root mean square and The correction factor is calculated according to formula (7). :

[0137] (7)

[0138] In this way, by using high-order numerical simulation to quantify the amplification effect of extreme waves on the vibration energy of the riser model, the results of ordinary wave experiments in the laboratory are extrapolated and corrected to a more realistic and conservative design condition that includes extreme events, thereby significantly improving the safety margin of the engineering design of the riser system.

[0139] Optionally, determine the correction factor corresponding to the attachment factor, including:

[0140] Establish the finite element model of the riser.

[0141] Based on the finite element model, the third vibration strain of the smooth riser model under waves was calculated. The fourth vibration strain of the riser model under waves, with increased diameter and roughness. .

[0142] The third vibration strain corresponding root mean square With the fourth vibration strain corresponding root mean square The ratio of is used as the correction factor for the attachment factor.

[0143] Determining the correction factor At that time, a finite element model of the riser was established using finite element software. First, the first response of the smooth riser model under waves was calculated. Then calculate the second response of the riser model with increased diameter and roughness. Calculate the strain of the third vibration separately. and the fourth vibration strain corresponding root mean square and The correction factor is calculated according to formula (8). :

[0144] (8)

[0145] In this way, by using finite element simulation to quantify the impact of marine organism attachment on the vibration energy of the riser model, the experimental results of the laboratory smooth new pipe can be extrapolated and corrected to the service state with biological attachment, thereby providing a more accurate and conservative data basis for the whole life cycle design and fatigue analysis of the riser.

[0146] Compare each correction factor with the data after the second correction. The product of these two numbers is used as the data after the third correction. As shown in formula (9):

[0147] (9)

[0148] in, , , Values ​​range from 1.0 to 1.1.

[0149] This disclosure provides a computer-readable storage medium storing computer-executable instructions configured to execute the above-described experimental analysis method for the riser vibration suppression-energy-saving system based on a powerless propeller.

[0150] The foregoing description and accompanying drawings fully illustrate embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included or substituted for parts and features of other embodiments. Embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from its scope. The scope of the present disclosure is limited only by the appended claims.

Claims

1. An experimental analysis method for a passive propeller-based riser vibration suppression- energy harvesting system, characterized by, The unpowered propeller-based riser vibration suppression-kinetic energy harvesting system comprises: a vibration simulation device for generating vibration; a riser model partially located in a water tank and having a top end connected to the vibration simulation device; an internal and external flow circulation system having a gas-liquid output end connected to a bottom end of the riser model; one or more turbulence devices arranged on an outer wall of the riser model; a power generation mechanism connected to the turbulence devices; the experimental analysis method comprises: performing a deep-sea vibration simulation experiment on the riser model by using the unpowered propeller-based riser vibration suppression-kinetic energy harvesting system to obtain experimental strain data; performing a first correction on the experimental strain data according to a difference between an experimental ocean current and an actual ocean current: analyzing the experimental strain data to determine a difference type between the experimental ocean current and the actual ocean current; and performing a first correction on the experimental strain data according to the difference type; constructing a numerical model of the water tank containing a boundary, simulating a bounded vibration strain of the riser model under the boundary and an unbounded vibration strain of the riser model under no boundary by using the numerical model of the water tank, determining a field region in which the riser model is located based on a shortest distance between the riser model and the boundary and a wavelength of a wave, and performing a second correction on the experimental strain data based on the field region in which the riser model is located, the bounded vibration strain and the unbounded vibration strain; determining correction coefficients corresponding to a wave factor, suspended sediments, a bubble factor and an attached object factor respectively, and performing a third correction on the experimental strain data according to the correction coefficients.

2. The experimental analysis method of passive propeller based riser vibration suppression- energy harvesting system according to claim 1, wherein, The analyzing the experimental strain data to determine a difference type between an experimental ocean current and an actual ocean current comprises: calculating target strain data generated by the riser model under the same sea conditions by numerical simulation; calculating a root mean square of the target strain data and a root mean square of the experimental strain data respectively according to the experimental strain data and the target strain data; determining that the difference type is an energy level difference in a case where the root mean square of the experimental strain data is less than a preset order of magnitude of the root mean square of the target strain data; determining that the difference type is a missing frequency structure and nonlinearity in a case where a high-order harmonic in the experimental strain data is less than a preset value.

3. The experimental analysis method of passive propeller based riser vibration suppression- energy harvesting system according to claim 1, wherein, The performing a first correction on the experimental strain data according to the difference type comprises: in a case where the difference type is an energy level difference, calculating a scaling factor according to the root mean square of the target strain data and the root mean square of the experimental strain data; and taking a product of the scaling factor and the experimental strain data as first corrected data. In the case of the difference type being frequency structure and non-linear loss, using the same wave parameter to perform high-order numerical simulation and simplified numerical simulation, respectively obtaining high-order numerical simulation strain data and simplified numerical simulation strain data ; based on the high-order numerical simulation strain data and the simplified numerical simulation strain data , performing model training to obtain a mapping relationship between the high-order numerical simulation strain data and the simplified numerical simulation strain data ; based on the mapping relationship between the high-order numerical simulation strain data and the simplified numerical simulation strain data , determining the first corrected data corresponding to the experimental strain data.

4. The experimental analysis method of passive propeller based riser vibration suppression- energy harvesting system according to claim 1, wherein, The determining a field region in which the riser model is located based on a shortest distance between the riser model and the boundary and a wavelength of a wave, and performing a second correction on the experimental strain data based on the field region in which the riser model is located, the bounded vibration strain and the unbounded vibration strain, comprises: If then the riser model is determined to be in a near-field region; if then the riser model is determined to be in a mid-field region; if then the riser model is determined to be in a negligible region; wherein, represents the shortest distance of the riser model from the tank boundary, represents the wavelength of the wave; in the case that the riser model is located in the near field region, performing Fourier transform on the bounded vibration strain and the unbounded vibration strain to obtain the distribution of vibration energy of the bounded vibration strain at different frequencies and the distribution of vibration energy of the unbounded vibration strain at different frequencies ; calculating a frequency domain correction factor according to the distribution of vibration energy of the bounded vibration strain at different frequencies and the distribution of vibration energy of the unbounded vibration strain at different frequencies ; performing Fourier transform on the first corrected data and multiplying the transformed data by the frequency domain correction factor; performing inverse Fourier transform on the multiplied result, and taking the transformed result as the second corrected data; in the case where the riser model is located in the mid-field region, based on the bounded vibration strain and the unbounded vibration strain calculating an overall energy level scaling factor; and multiplying the overall energy level scaling factor with the first modified data as the second modified data.

5. The experimental analysis method of passive propeller based riser vibration suppression- energy harvesting system according to claim 1, wherein, The determining correction coefficients corresponding to a wave factor, suspended sediments, a bubble factor and an attached object factor respectively, and performing a third correction on the experimental strain data according to the correction coefficients, comprises: calculating a correction coefficient corresponding to the wave factor: performing a vibration simulation using a high-order nonlinear numerical wave tank containing a wave breaking and freak wave model; obtaining a first vibration strain under a general irregular wave condition and a second vibration strain under an extreme wave condition ; taking the ratio of the root mean square of the first vibration strain and the root mean square of the second vibration strain corresponding to the wave factor as the correction coefficient corresponding to the wave factor; calculating a correction coefficient corresponding to the attachment factor: establishing a finite element model of the riser model; calculating a third vibration strain of the smooth riser model under the wave based on the finite element model , and a fourth vibration strain of the riser model with increased diameter and roughness under the wave ; taking a ratio of a root mean square corresponding to the third vibration strain and a root mean square corresponding to the fourth vibration strain as the correction coefficient corresponding to the attachment factor taking a product of each of the correction coefficients and the second corrected data as third corrected data.

6. The experimental analysis method of passive propeller based riser vibration suppression- energy harvesting system according to claim 1, wherein, The turbulence device comprises: A positioning mechanism is sleeved and fixed to the outer wall of the riser model; A rotating mechanism is sleeved to the outer wall of the riser model and rotatably connected with the positioning mechanism; A propeller mechanism is connected with the side of the rotating mechanism; When the ocean current flows through the outer surface of the riser model, the propeller mechanism drives the rotating mechanism to rotate, and reaches balance when the orientation of the blades in the propeller mechanism and the flow direction of the ocean current are 180° in the horizontal plane.

7. The experimental analysis method of the passive propeller-based riser vibration suppression and power generation system according to claim 6, wherein The positioning mechanism comprises: a first sleeve sleeved and fixed to the outer wall of the riser model, and provided with a supporting arm; a first gear sleeved to the outer wall of the riser model and connected to the top of the first sleeve, and engaged with the rotating mechanism; a circular ring sleeved to the outside of the first sleeve, supported by the supporting arm; and provided with a connecting piece; the positioning mechanism is connected with the rotating mechanism through the connecting piece, and rotatably connected with the rotating mechanism through the first gear; and / or The rotating mechanism comprises: a second sleeve sleeved to the outer wall of the riser model; a plurality of supporting legs provided at the bottom of the second sleeve; a plurality of second gears corresponding to each supporting leg, rotatably sleeved to the outer wall of the corresponding supporting leg; the rotating mechanism is connected with the positioning mechanism through each supporting leg, and rotatably connected with the positioning mechanism through each second gear; a flow direction marker is provided at the top of the second sleeve, and the straight line along the length of the flow direction marker in the horizontal direction is perpendicular to the rotation plane of the propeller mechanism; and / or The propeller mechanism comprises: a third sleeve vertically connected to the side of the rotating mechanism; a rotating shaft provided in the third sleeve along the axial direction of the third sleeve; a plurality of blades connected with the rotating shaft and located outside the third sleeve.

8. The experimental analysis method of the passive propeller-based riser vibration suppression and power generation system according to claim 7, wherein The power generation mechanism comprises: a permanent magnet provided on the outer wall of the rotating shaft; a power generation coil provided on the inner wall of the third sleeve; a bundled cable provided in the interlayer of the riser model and connected with the power generation coil, for connecting with external electrical equipment; The riser model comprises: a plurality of pipe sections rotatably connected; each turbulence device corresponds to each pipe section and is arranged on the outer wall of the corresponding pipe section; each pipe section comprises: an oil pipeline; a protective tube sleeved outside the oil pipeline and forming a containing cavity with the oil pipeline; conductive contacts are respectively arranged at the top and bottom of the containing cavity, thereby closing the containing cavity; the bundled cable is distributed in the containing cavity, and the two ends are respectively connected with the conductive contacts at the top and bottom, thereby transmitting electrical energy in each pipe section through the conductive contacts.

9. The experimental analysis method of the passive propeller-based riser vibration suppression system according to claim 1, wherein the vibration simulation device comprises: a support device; a support frame arranged on the support device; a motor arranged on the support frame; a Scotch yoke mechanism, a power input portion of the Scotch yoke mechanism being in transmission connection with the motor, a power output portion of the Scotch yoke mechanism being connected with a top end of a riser model through a universal joint; the Scotch yoke mechanism being slidably connected with the support frame in a vertical direction; or the Scotch yoke mechanism being slidably connected with the support frame in a horizontal direction; and / or, the internal and external flow circulation system comprises: a water tank and a gas tank; a liquid pipeline, one end of the liquid pipeline being in communication with the water tank, the other end of the liquid pipeline being in communication with a bottom end of the riser model through a three-way valve and a flow pipeline; a gas pipeline, one end of the gas pipeline being in communication with the gas tank, the other end of the gas pipeline being in communication with the bottom of the riser model through the three-way valve and the flow pipeline. ​

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