Self-excited vibration experimental device under interference of high reynolds number rigid double riser

Abstract

The present application relates to the technical field of ocean engineering, and particularly relates to a high Reynolds number rigid double riser self-excited vibration experimental device under interference, which comprises an outer fixed module, an inner sliding module, a cross-flow vibration module, a measuring module and a rigid riser module, the outer fixed module is rigidly connected with a circulating water tank or a trailer, the inner sliding module is installed on the sliding block of the outer fixed module, the cross-flow vibration module is installed on the inner sliding module, reciprocating motion with extremely low friction can be realized along the cross-flow direction through the air floating shaft sleeve, the rigid riser module is fixed at the lower end of the cross-flow vibration module, and the measuring module synchronously measures the displacement of the rigid riser and the fluid load received during the experiment, the overall structure of the present application is firm, the riser spacing, relative arrangement angle and mass ratio of the two groups of rigid riser modules are adjustable, the motion freedom of the two groups of cross-flow vibration modules is controllable, various motion working conditions can be simulated, and the present application is suitable for self-excited vibration experimental research under the interference of high Reynolds number rigid double risers.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, and in particular to a self-excited vibration experimental device under high Reynolds number rigid double riser interference. Background Technology

[0002] Offshore risers are key equipment in offshore oil and gas development, playing a vital role in connecting the seabed to oil and gas platforms and transporting oil and gas. In actual marine environments, risers are subjected to ocean currents, causing vortices to be released periodically on both sides. This results in periodic vibrations of the riser in directions perpendicular to and in sync with the incoming current. When the vibration frequency is close to a certain natural frequency of the riser, it can trigger a large-amplitude vibration phenomenon known as "vortex-induced vibration".

[0003] In deep-sea floating platform operations, due to space constraints, risers are often arranged in a cluster. There is a strong hydrodynamic interference coupling between the risers. That is, the upstream riser undergoes a typical vortex-induced vibration response under the excitation of the free flow, while the downstream riser undergoes a more complex wake-induced vibration response under the excitation of the wake vortex of the upstream riser. This phenomenon is called multi-pipe interference.

[0004] Currently, industry and academia mainly focus on the vortex-induced characteristics of single-tube vortex-induced vibrations, while the dynamic behavior of vortex-induced wake vortex-induced vibrations under the interference of two tubes has not been fully revealed. A patent from 2012 (CN201210439276.0) provides a device for simulating self-excited oscillations under mutual interference of two risers in uniform flow. This device numerically solves the riser motion equations based on measurement data and controls the risers to move according to the calculated response through a drive device, thereby simulating self-excited vibrations. However, this method has the following drawbacks: the experimental device generates motion through external force, which cannot realistically reproduce the self-excited vibrations of risers in a constant flow field. Furthermore, under high Reynolds number flow, the numerical solution based on the mechanical model may be distorted from the actual physical phenomena, leading to doubts about its reliability and applicability; the arrangement of the two sets of rigid risers is monotonous, and the relative position and angle between the risers cannot be flexibly adjusted, making it difficult to comprehensively study the complex coupling behavior between multiple risers.

[0005] Therefore, it is of great significance to develop an experimental device that can reliably and effectively observe the vortex-induced vibration characteristics of multi-tube risers. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a self-excited vibration experimental device under high Reynolds number rigid double riser interference, suitable for vortex-induced vibration experiments of two rigid risers under high Reynolds number flow.

[0007] To achieve the above objectives, the present invention provides a self-excited vibration experimental device under high Reynolds number rigid double riser interference, the device comprising an external fixed module, an internal sliding module, a transverse flow vibration module, a rigid riser module, and a measurement module;

[0008] The external fixing module is rigidly connected to a structure such as a circulating water tank or a trailer.

[0009] The inner sliding module, the cross-flow vibration module, the measurement module, and the rigid riser module are all provided in two sets. The inner sliding module is installed on the outer fixed module and is slidably connected to the outer fixed module. The cross-flow vibration module is installed on the inner sliding module. The rigid riser module is installed at the lower end of the cross-flow vibration module and drives the cross-flow vibration module to move under the action of water flow.

[0010] The two sets of transverse flow vibration modules can be connected by a third connecting rod to achieve synchronous movement of the two sets of transverse flow vibration modules;

[0011] The measurement module is installed on both sides of the external fixed module and on the transverse vibration module to simultaneously measure the displacement of the rigid riser and the fluid load it experiences during the experiment.

[0012] Preferably, the external fixing module consists of a main frame, a linear guide rail, and a slider. The linear guide rail is fixedly installed on the main frame, and the slider is installed on the linear guide rail and slides along the linear guide rail.

[0013] Preferably, the main frame is a frame formed by overlapping several aluminum profiles with L-shaped connectors, T-shaped connectors and 90-degree corner brackets;

[0014] The aluminum profile is a long strip standard profile, and two connecting channels are provided on each of its four sides along its length.

[0015] Preferably, each set of the inner sliding modules includes a spring suspension plate, a first hook, a first washer, a first bolt, a first connecting rod, and a base plate symmetrically arranged on both sides of the main frame;

[0016] The spring suspension plate is a slender straight plate with three slots in the middle. The top and bottom slots are slot one, and the middle slot is slot two. The two first hooks are fixed in the top and bottom slots one by first bolts and first washers respectively.

[0017] The base plate is fixed to the slider by bolts and can be fixedly connected to the main frame by the base plate fastener, thereby restricting the sliding of the inner sliding module;

[0018] The first connecting rod is disposed at the upper and lower ends of the slot two, and one end of the first connecting rod is fixedly connected to the spring suspension plate, and the other end is fixedly connected to the bottom plate;

[0019] The base plate is a long plate with a groove three in the middle, which corresponds to the groove two. Grooves are provided on both sides of the base plate.

[0020] Preferably, each set of transverse vibration modules includes an inner end plate, an outer end plate, an optical shaft seat, an optical shaft, an air-bearing bushing, a second connecting rod, a second hook, at least two springs, a weight, a screw, a first nut, a second washer, a diagonal steel wire, a steel wire locking piece, a third bolt, a second bolt, and a second nut, all symmetrically arranged on both sides of the main frame.

[0021] The two ends of the inclined steel wire are connected to the outer end plates on both sides through steel wire locking parts to realize the synchronous movement of the outer end plates on both sides;

[0022] The optical axis is fixed in the groove by an optical axis seat. The optical axis seat is fixedly set at the upper and lower ends of the groove. The optical axis axis is perpendicular to the liquid surface of the water tank. Several air-floating bushings are sleeved on the outside of the optical axis, and the air-floating bushings are slidably connected to the optical axis. One side of the inner end plate is fixedly connected to the air-floating bushing, and the other side is fixedly connected to the outer end plate.

[0023] Two limiting blocks are respectively set on the upper and lower sides of the second connecting rod and are fixedly connected to the base plate by bolts to restrict the movement of the transverse vibration module.

[0024] Preferably, the second connecting rod is a slender rod, one end of which is fixedly connected to the inner end plate, and the other end of which is a free-extending end;

[0025] A circular hole is provided on the free extension end, and the second hook is fixed on the free extension end by cooperating with the circular hole. One end of the spring is connected to the first hook, and the other end is connected to the second hook.

[0026] The third connecting rod is a long straight rod, and its two ends are fixedly connected to two adjacent second connecting rods in the two sets of transverse flow vibration modules by C-clamps.

[0027] Preferably, the wire locking component is an aluminum block with a through hole and a through threaded hole on one side and a non-through threaded hole on the other adjacent side. One end of the inclined steel wire is inserted into the through hole, and the inclined steel wire and the wire locking component are fixedly connected by a third bolt that engages with the non-through threaded hole.

[0028] The steel wire locking component and the outer end plate are fixedly connected by the second bolt and the second nut engaging with the through threaded hole. The steel wire can be tightened by tightening the second bolt and the second nut.

[0029] Preferably, the inner end plate has a connecting hole one, the upper part of the outer end plate has a circular hole one, a weight is placed in the circular hole one, a connecting hole two is opened in the center of the weight, and the weight is fixedly connected to the inner end plate by a screw, a first nut and a second washer;

[0030] The second gasket is disposed between the screw and the inner end plate, and between the first nut and the weight.

[0031] Preferably, the rigid riser module includes a rigid riser and a foam cylinder. The rigid riser is made of composite lightweight carbon fiber material and has small holes at both ends for wiring and to prevent the cable of the force sensor from contacting the rigid riser.

[0032] The foam cylinder is made of EPS foam and is glued to the inside of the rigid riser to prevent water from affecting the quality of the rigid riser model and the measurement of hydrodynamic loads.

[0033] Preferably, the measurement module includes a displacement sensor, a displacement sensor fixture, a matching magnetic ring, a magnetic ring fixing component, a three-part force sensor, a dumbbell-shaped component, a force sensor fixing component, a fourth bolt, a fifth bolt, a plastic sleeve, a sixth bolt, and a third nut. The displacement sensor fixture is fixed on the external fixing module, and the displacement sensor is fixedly installed on the displacement sensor fixture.

[0034] The three-part force sensor is installed at both ends inside the rigid riser. One end of the three-part force sensor is fixedly connected to the outer end plate through the force sensor fixing component and the fourth bolt, and the other end is fixedly connected to the dumbbell-shaped component. The force sensor fixing component is an aluminum disc.

[0035] One end of the magnetic ring fixing component is fixed to the second connecting rod, and the other end is fixedly connected to the matching magnetic ring.

[0036] The plastic sleeve is fixedly installed on the dumbbell-shaped component by the sixth bolt and the third nut;

[0037] One end of the dumbbell-shaped component is fixedly connected to the three-part force sensor by the fifth bolt, and the other end is chamfered to form an arc plate end. The arc plate end is in contact with the inner wall of the rigid riser, which can prevent the bending moment from being transmitted to the three-part force sensor.

[0038] Therefore, the present invention provides a self-excited vibration experimental device under high Reynolds number rigid double riser interference, which has the following beneficial effects: The present invention uses a cylindrical three-part force sensor, which is embedded inside the rigid riser model and forms a hinged connection with the rigid riser. This can avoid the sensor being subjected to bending moment, thereby accurately measuring the fluid load on the rigid riser model in the high Reynolds flow field.

[0039] The present invention sets cross-bracing steel wires between the outer end plates on both sides, so as to keep the movement of the two ends of the rigid riser synchronized, and avoid the jamming between the air bearing bush and the optical axis, which would greatly increase the frictional damping of the system and affect the experimental results.

[0040] The present invention has a robust overall structure, which can ensure the stable operation of the main structure and sensors even under the large load generated by high Reynolds number flow. Compared with traditional devices, it reduces the risk of failure under extreme conditions and improves the stability and durability of the experimental device. During the experiment, important sensitive parameters of the two sets of rigid risers vortex-induced vibration experiments can be flexibly adjusted, such as the mass ratio of the rigid risers, natural frequency, and the distance and relative arrangement angle of the two risers, thereby improving experimental efficiency.

[0041] This invention can conveniently control the movement of the transverse vibration module, thereby enabling simulation of various working conditions such as one set of rigid risers moving while the other set remains stationary, two sets of rigid risers moving synchronously, and two sets of rigid risers moving individually. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the overall structure of a self-excited vibration experimental device under high Reynolds number rigid double-pipe interference in an embodiment of the present invention.

[0043] Figure 2 This is a schematic diagram of the fixing method of the external fixing module and the displacement sensor in an embodiment of the present invention;

[0044] Figure 3 This is an exploded view of the internal modules in an embodiment of the present invention;

[0045] Figure 4 This is a schematic diagram of the spring suspension plate in an embodiment of the present invention;

[0046] Figure 5 for Figure 3 Enlarged view of point A in the middle;

[0047] Figure 6 for Figure 3 Enlarged view of point B in the middle;

[0048] Figure 7 for Figure 3 Enlarged view of point C in the middle;

[0049] Figure 8 This is a schematic diagram of the installation of the three-part force sensor in an embodiment of the present invention;

[0050] Figure 9 This is an exploded view of the three-part force sensor in an embodiment of the present invention;

[0051] Figure 10 This is a cross-sectional view of the rigid riser in an embodiment of the present invention;

[0052] Figure 11 This is a schematic diagram showing the spacing and relative arrangement angle of the two sets of risers;

[0053] Figure 12 A schematic diagram of the self-excited vibration of a set of risers fixed together.

[0054] Figure 13 This is a schematic diagram of the synchronous self-excited vibration of two sets of risers;

[0055] Figure 14 Schematic diagram of independent self-excited vibration of two sets of risers

[0056] Figure 15 This is a schematic diagram of the parameters for two sets of riser models;

[0057] Figure Labels

[0058] 1. External fixing module; 11. Aluminum profile; 12. L-shaped connector; 13. T-shaped connector; 14. Angle bracket; 15. Linear guide rail; 16. Slider; 2. Internal sliding module; 21. Spring suspension plate; 211. Slot 1; 212. Slot 2; 22. First hook; 23. First washer; 24. First bolt; 25. First connecting rod; 26. Base plate; 261. Groove; 262. Slot 3; 263. Limiting block; 364. C-clamp; 365. Base plate fixing component; 3. Crossflow vibration module; 31. Inner end plate; 32. Outer end plate; 321. Circular hole 1; 33. Optical axis seat; 34. Optical axis; 35. Air bearing bush; 36. Second connecting rod; 37. Second hook; 38. Spring; 39. Weight; 310. Screw 311. First nut; 312. Second washer; 313. Diagonal steel wire; 314. Steel wire locking component; 3141. Through hole; 3142. Through threaded hole; 3143. Non-through threaded hole; 315. Third bolt; 316. Second bolt; 317. Second nut; 4. Rigid riser module; 41. Rigid riser; 42. Foam cylinder; 5. Measurement module; 51. Displacement sensor; 52. Displacement sensor fixture; 53. Matching magnetic ring; 54. Magnetic ring fixing component; 55. Three-part force sensor; 56. Dumbbell-shaped component; 561. Arc plate end; 57. Force sensor fixing component; 58. Fourth bolt; 59. Fifth bolt; 510. Plastic sleeve; 511. Sixth bolt; 512. Third nut; 6. Third connecting rod. Detailed Implementation

[0059] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0060] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0061] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0062] Example

[0063] like Figure 1 As shown, the present invention is a self-excited vibration experimental device under high Reynolds number rigid double riser interference. The device includes an outer fixed module 1, an inner sliding module 2, a transverse flow vibration module 3, a rigid riser module 4, and a measurement module 5. The outer fixed module 1 is rigidly connected to a structure such as a circulating water tank or a trailer.

[0064] In this embodiment, the inner sliding module 2, the cross-flow vibration module 3, the measurement module 5, and the rigid riser module 4 are all provided in two sets. The inner sliding module 2 is installed on the outer fixed module 1 and is slidably connected to the outer fixed module 1. The cross-flow vibration module 3 is installed on the inner sliding module 2 and can achieve reciprocating motion with extremely low friction along the cross-flow direction through the air-float bushing 35. The rigid riser module 4 is installed at the lower end of the cross-flow vibration module 3. The rigid riser module 4 is fully submerged about 10 times the pipe diameter below the water surface and can drive the cross-flow vibration module 3 to move under the action of water flow.

[0065] The two sets of transverse flow vibration modules 3 are connected by a third connecting rod 6. In this embodiment, the third connecting rod 6 is a long straight rod, and its two ends are fixedly connected to two adjacent second connecting rods 36 in the two sets of transverse flow vibration modules 3 by C-clamps 364, which can control the synchronous movement of the two sets of rigid riser modules 4.

[0066] The measurement module 5 is installed on both sides of the external fixed module 1 and on the transverse vibration module 3 to simultaneously measure the displacement of the rigid riser 41 and the fluid load it experiences during the experiment.

[0067] like Figure 2 As shown, the external fixing module 1 consists of a main frame, a linear guide rail 15, and a slider 16. The linear guide rail 15 is fixedly installed on the main frame, and the slider 16 is installed on the linear guide rail 15 and slides along the linear guide rail 15. The main frame is a stable frame formed by several aluminum profiles 11 overlapping each other through L-shaped connectors 12, T-shaped connectors 13, and 90-degree angle brackets 14. The aluminum profiles 11 are long strip standard profiles, and two connecting channels are provided on each of the four sides along their length.

[0068] like Figure 1 , Figure 3 and Figure 4 As shown, each sliding module 2 includes a spring suspension plate 21, a first hook 22, a first washer 23, a first bolt 24, a first connecting rod 25, and a base plate 26 symmetrically arranged on both sides of the main frame; the spring suspension plate 21 is a slender straight plate with three slots in the middle, the upper and lower slots are slot one 211, and the middle slot is slot two 212. The two first hooks 22 are fixed in the upper and lower slots one 211 respectively by the first bolt 24 and the first washer 23.

[0069] The base plate 26 is fixed to the slider 16 by bolts and can slide together with the slider 16. During the formal experiment, the base plate 26 can be fixed to the main frame by the base plate fixing part 365. The first connecting rod 25 is set at the upper and lower ends of the slot 212, and one end of the first connecting rod 25 is fixedly connected to the spring suspension plate 21, and the other end is fixedly connected to the base plate 26.

[0070] The base plate 26 is a long plate with a groove 262 in the middle, which corresponds to the groove 212. Grooves 261 are provided on both sides of the base plate 26.

[0071] like Figure 3 and Figure 6 As shown, each set of transverse vibration modules 3 includes an inner end plate 31, an outer end plate 32, an optical axis seat 33, an optical axis 34, an air-bearing bushing 35, a second connecting rod 36, a second hook 37, at least two springs 38, a weight 39, a screw 310, a first nut 311, a second washer 312, a diagonal steel wire 313, a steel wire locking piece 314, a third bolt 315, a second bolt 316, and a second nut 317. The two ends of the diagonal steel wire 313 are connected to the outer end plates 32 on both sides through the steel wire locking piece 314 to realize the synchronous movement of the outer end plates 32 on both sides.

[0072] In this embodiment, the wire locking component 314 is an aluminum block with a through hole 3141 and a through threaded hole 3142 on one side, and a non-through threaded hole 3143 on the other adjacent side. One end of the inclined steel wire 313 is inserted into the through hole 3141. The inclined steel wire 313 and the wire locking component 314 are fixedly connected by a third bolt 315 engaging with the non-through threaded hole 3143. The wire locking component 314 and the outer end plate 32 are fixedly connected by a second bolt 316 and a second nut 317 engaging with the through threaded hole 3142. Tightening the second bolt 316 and the second nut 317 can tighten the steel wire.

[0073] The optical axis 34 is fixed in the groove 261 by the optical axis seat 33. The optical axis seat 33 is fixedly set at the upper and lower ends of the groove 261. The optical axis 34 is perpendicular to the liquid surface of the water tank. Several air-floating bushings 35 are sleeved on the outside of the optical axis 34, and the air-floating bushings 35 are slidably connected to the optical axis 34, which can reduce the system damping. One side of the inner end plate 31 is fixedly connected to the air-floating bushing 35, and the other side is fixedly connected to the outer end plate 32.

[0074] Two limiting blocks 263 are respectively disposed on the upper and lower sides of the second connecting rod 36 and are fixedly connected to the base plate 26 by bolts to restrict the movement of the transverse vibration module 3. In this embodiment, the second connecting rod 36 is a slender rod, one end of which is fixedly connected to the inner end plate 31, and the other end is a free extension end with a circular hole. The second hook 37 is fixed to the free extension end by cooperating with the circular hole. One end of the spring 38 is connected to the first hook 22, and the other end is connected to the second hook 37.

[0075] like Figure 3 and Figure 5 As shown, the inner end plate 31 has a connecting hole 1, and the upper part of the outer end plate 32 has a circular hole 321. A weight 39 is placed in the circular hole 321. A connecting hole 2 is opened in the center of the weight 39. The weight 39 is fixedly connected to the inner end plate 31 through a screw 310, a first nut 311 and a second washer 312. The weight 39 is made according to the difference between the mass of the overall movable component and the preset mass ratio. The second washer 312 is placed between the screw 310 and the inner end plate 31 and between the first nut 311 and the weight 39.

[0076] like Figure 3 , Figure 8 and Figure 10 As shown, the rigid riser module 4 includes a rigid riser 41 and a foam cylinder 42. The rigid riser 41 is made of composite lightweight carbon fiber material, and small holes are opened at both ends for wiring and to prevent the cable of the three-part force sensor 55 from contacting the rigid riser 41.

[0077] The foam cylinder 42 is made of EPS foam and is glued to the inside of the rigid riser 41 to prevent water from entering and affecting the quality of the rigid riser 41 model and the measurement of hydrodynamic loads.

[0078] like Figure 2 , Figure 3 , Figure 7 and Figure 9 As shown, the measurement module 5 includes a displacement sensor 51, a displacement sensor clamp 52, a matching magnetic ring 53, a magnetic ring fixing component 54, a three-part force sensor 55, a dumbbell-shaped component 56, a force sensor fixing component 57, a fourth bolt 58, a fifth bolt 59, a plastic sleeve 510, a sixth bolt 511, and a third nut 512. The displacement sensor clamp 52 is fixed on the outer fixing module 1, and the displacement sensor 51 is fixedly installed on the displacement sensor clamp 52.

[0079] The three-part force sensor 55 is installed at both ends inside the rigid riser 41. One end of the three-part force sensor 55 is fixedly connected to the outer end plate 32 through the force sensor fixing member 57 and the fourth bolt 58, and the other end is fixedly connected to the dumbbell-shaped member 56. In this embodiment, the force sensor fixing member 57 is an aluminum disc.

[0080] One end of the magnetic ring fixing component 54 is fixed to the second connecting rod 36 and moves with the transverse vibration module 3. The other end is fixedly connected to the matching magnetic ring 53. The plastic sleeve 510 is fixedly installed on the dumbbell-shaped component 56 by the sixth bolt 511 and the third nut 512.

[0081] One end of the dumbbell-shaped component 56 is fixedly connected to the three-part force sensor 55 by the fifth bolt 59, and the other end is chamfered to form an arc plate end 561. The arc plate end 561 is in contact with the inner wall of the rigid riser 41, which can prevent the bending moment from being transmitted to the three-part force sensor 55.

[0082] The manufacturing and installation process of this embodiment is as follows:

[0083] Preparation and component pre-assembly: First, select appropriate profiles and connectors according to the size of the components installed in the circulating water tank or trailer, the specific conditions of the experimental working, the size of the rigid riser 41, and the economics of the experiment. Assemble the main frame by overlapping each other, assemble the linear guide rail 15 and the slider 16 onto the main frame, and assemble the external fixing module 1 for later use.

[0084] Assemble the optical axis seat 33, optical axis 34, air bearing bush 35, and limit block 263 onto the base plate 26 for later use; install the first hook 22 onto the spring suspension plate 21 for later use, and the installation position can be flexibly changed as needed later; install the second hook 37 onto the second connecting rod 36 for later use; install the displacement sensor matching magnetic ring 53 onto the magnetic ring fixing part 54 for later use.

[0085] Main structure installation: The assembled base plate 26 is fixed to the mounting surface of the slider 16 with bolts; one end of the first connecting rod 25 is fixed to the base plate 26 with bolts, and the assembled spring suspension plate 21 is fixed to the other end of the first connecting rod 25 with bolts; the inner end plate 31 is fixed to the air bearing sleeve 35 with bolts, and the outer end plate 32 is fixed to the inner end plate 31 with bolts; the assembled second connecting rod 36 is fixed to the inner end plate 31; one end of the spring 38 is hung on the first hook 22, and the other end is hung on the second hook 37; the third connecting rod 6 is fixed to the second connecting rod 36 with C-clamp 364.

[0086] Install the rigid riser 41 and the three-part force sensor 55: First, place the foam cylinder 42 inside the rigid riser 41. After verifying that the waterproof effect is reliable, set the three-part force sensor 55 at the inner port of the rigid riser 41 and fix it to the lower end of the outer end plate 32 by force sensor fixing piece 57.

[0087] Install the inclined steel wire 313: Insert the inclined steel wire 313 into the round hole of the steel wire locking member 314. The third bolt 315 engages with the non-through threaded hole 3143. Tighten the third bolt 315 to fix the inclined steel wire 313 to the steel wire locking member 314. The second bolt 316, the second nut 317 engage with the through threaded hole 3142. By tightening the second bolt 316 and the second nut 317, the steel wire locking member 314 is squeezed, thereby achieving the tensioning of the inclined steel wire 313.

[0088] After the above assembly is completed, the wiring is rewiring. The signal lines and power lines of the three-part force sensor 55 and displacement sensor 51, as well as the air tube of the air bearing bush 35, are reasonably arranged along the profile of the outer fixing module 1 using waterproof tape to avoid the lines swaying in the water during the experiment or some lines being improperly arranged to hinder the movement of the transverse vibration module 3.

[0089] Finally, the experimental setup is fixed to the water tank or trailer structure, and the inner sliding module 2 is fixed to the outer fixed module 1 by the base plate fixing member 365; specifically, the base plate 26 fixing member is fixed to the base plate 26 on one side and to the profile of the outer fixed module 1 on the other side by bolts; after fixing, the signal line and power line of the measuring module 5 are connected and the air bearing bush 35 is vented, and the dual-tube self-excited vibration experiment can be carried out.

[0090] like Figure 11 As shown, in this embodiment, the distance between the two rigid risers 41 can be flexibly adjusted by moving the slider 16, which can further study the influence of different distances on the vortex-induced vibration characteristics of the two rigid risers; by installing the first hooks 22 of the two sets of inner sliding modules 2 at different heights, it can be used to explore the vortex-induced vibration law of the two sets of rigid risers under different arrangement angles.

[0091] like Figure 12 , Figure 13 and Figure 14 As shown, in some embodiments, the limiting block 263, the third connecting rod 6 and the C-clamp 364 can realize various working conditions such as one set of rigid risers moving while the other set of rigid risers remains stationary, the two sets of rigid risers moving synchronously, and the two sets of rigid risers moving independently.

[0092] like Figure 15 As shown, in some embodiments, the weights of the two sets of transverse vibration modules 3 are flexibly adjusted. m 1 and m 2 This allows for further investigation into the vortex-induced vibration characteristics of two sets of rigid risers with the same or different mass ratios; in some implementations, the spring stiffness of the two sets of transverse vibration modules 3 can be flexibly adjusted. k 1 and k 2 This allows for further investigation into the vortex-induced vibration patterns of two sets of rigid risers with the same or different natural frequencies.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An experimental apparatus for self-excited vibration under high Reynolds number rigid double-riser interference, characterized in that: The device includes an external fixing module, an internal sliding module, a cross-flow vibration module, a rigid riser module, and a measurement module. The external fixing module is rigidly connected to a structure such as a circulating water tank or a trailer. The inner sliding module, the cross-flow vibration module, the measurement module, and the rigid riser module are all provided in two sets. The inner sliding module is installed on the outer fixed module and is slidably connected to the outer fixed module. The cross-flow vibration module is installed on the inner sliding module. The rigid riser module is installed at the lower end of the cross-flow vibration module and drives the cross-flow vibration module to move under the action of water flow. The two sets of transverse vibration modules can be connected by a third connecting rod to achieve synchronous movement; The measurement module is installed on both sides of the external fixed module and on the transverse vibration module to simultaneously measure the displacement of the rigid riser and the fluid load it experiences during the experiment. The external fixing module consists of a main frame, a linear guide rail, and a slider. The linear guide rail is fixedly installed on the main frame, and the slider is installed on the linear guide rail and slides along the linear guide rail. Each set of inner sliding modules includes a spring suspension plate, a first hook, a first washer, a first bolt, a first connecting rod, and a base plate symmetrically arranged on both sides of the main frame; The spring suspension plate is a slender straight plate with three slots in the middle. The top and bottom slots are slot one, and the middle slot is slot two. The two first hooks are fixed in the top and bottom slots one by first bolts and first washers respectively. The base plate is fixed to the slider by bolts and can be fixedly connected to the main frame by the base plate fastener, thereby restricting the sliding of the inner sliding module; The first connecting rod is disposed at the upper and lower ends of the slot two, and one end of the first connecting rod is fixedly connected to the spring suspension plate, and the other end is fixedly connected to the bottom plate; The base plate is a long plate with a groove three in the middle, which corresponds to the groove two. Grooves are provided on both sides of the base plate. Each set of transverse vibration modules includes an inner end plate, an outer end plate, an optical shaft seat, an optical shaft, an air-bearing bushing, a second connecting rod, a second hook, at least two springs, a weight, a screw, a first nut, a second washer, a diagonal steel wire, a steel wire locking device, a third bolt, a second bolt, and a second nut, all symmetrically arranged on both sides of the main frame. The two ends of the diagonal steel wire are connected to the outer end plates on both sides through the steel wire locking device to achieve synchronous movement of the outer end plates on both sides. The optical axis is fixed in the groove by an optical axis seat, which is fixedly disposed at the upper and lower ends of the groove. The optical axis is perpendicular to the liquid surface of the water tank. Several air-floating bushings are sleeved on the outside of the optical axis, and the air-floating bushings are slidably connected to the optical axis. One side of the inner end plate is fixedly connected to the air-floating bushing, and the other side is fixedly connected to the outer end plate. Two limiting blocks are respectively disposed on the upper and lower sides of the second connecting rod and fixedly connected to the base plate by bolts to limit the movement of the transverse flow vibration module. The second connecting rod is a slender rod, one end of which is fixedly connected to the inner end plate, and the other end of which is a free extension end; A circular hole is provided on the free extension end, and the second hook is fixed on the free extension end by cooperating with the circular hole. One end of the spring is connected to the first hook, and the other end is connected to the second hook.

2. The experimental apparatus for self-excited vibration under high Reynolds number rigid double-riser interference as described in claim 1, characterized in that: The main frame is a frame made up of several aluminum profiles connected together by L-shaped connectors, T-shaped connectors and 90-degree corner brackets. The aluminum profile is a long strip standard profile, and two connecting channels are provided on each of its four sides along its length.

3. The experimental apparatus for self-excited vibration under high Reynolds number rigid double-riser interference as described in claim 1, characterized in that: The third connecting rod is a long straight rod, and its two ends are fixedly connected to two adjacent second connecting rods in the two sets of transverse flow vibration modules by C-clamps.

4. The experimental device for self-excited vibration under high Reynolds number rigid double-riser interference as described in claim 3, characterized in that: The steel wire locking component is an aluminum block with a through hole and a through threaded hole on one side and a non-through threaded hole on the other adjacent side. One end of the inclined steel wire is inserted into the through hole, and the inclined steel wire and the steel wire locking component are fixedly connected by a third bolt that engages with the non-through threaded hole. The steel wire locking component and the outer end plate are fixedly connected by the second bolt and the second nut engaging with the through threaded hole. The steel wire can be tightened by tightening the second bolt and the second nut.

5. The experimental device for self-excited vibration under interference of a high Reynolds number rigid double-riser tube as described in claim 3, characterized in that: The inner end plate has a connecting hole 1, and the upper part of the outer end plate has a circular hole 1. A weight is placed in the circular hole 1, and a connecting hole 2 is opened in the center of the weight. The weight is fixedly connected to the inner end plate through a screw, a first nut and a second washer. The second gasket is disposed between the screw and the inner end plate, and between the first nut and the weight.

6. The experimental apparatus for self-excited vibration under interference of a high Reynolds number rigid double-riser tube as described in claim 3, characterized in that: The rigid riser module includes a rigid riser and a foam cylinder. The rigid riser is made of composite lightweight carbon fiber material and has small holes at both ends for wiring and to prevent the cable of the force sensor from contacting the rigid riser. The foam cylinder is made of EPS foam and is glued to the inside of the rigid riser to prevent water from affecting the quality of the rigid riser model and the measurement of hydrodynamic loads.

7. The experimental apparatus for self-excited vibration under interference of a high Reynolds number rigid double-riser tube as described in claim 4, characterized in that: The measurement module includes a displacement sensor, a displacement sensor fixture, a matching magnetic ring, a magnetic ring fixing component, a three-part force sensor, a dumbbell-shaped component, a force sensor fixing component, a fourth bolt, a fifth bolt, a plastic sleeve, a sixth bolt, and a third nut. The displacement sensor fixture is fixed on the external fixing module, and the displacement sensor is fixedly installed on the displacement sensor fixture. The three-part force sensor is installed at both ends inside the rigid riser. One end of the three-part force sensor is fixedly connected to the outer end plate through the force sensor fixing component and the fourth bolt, and the other end is fixedly connected to the dumbbell-shaped component. The force sensor fixing component is an aluminum disc. One end of the magnetic ring fixing component is fixed to the second connecting rod, and the other end is fixedly connected to the matching magnetic ring. The plastic sleeve is fixedly installed on the dumbbell-shaped component by the sixth bolt and the third nut; One end of the dumbbell-shaped component is fixedly connected to the three-part force sensor by the fifth bolt, and the other end is chamfered to form an arc plate end. The arc plate end is in contact with the inner wall of the rigid riser, which can prevent the bending moment from being transmitted to the three-part force sensor.

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