A kind of active ocean riser vortex-induced vibration suppression device based on vibration reduction fin

Abstract

The application discloses a kind of active ocean riser vortex-induced vibration suppression device based on vibration reduction fin, to solve the problems such as the structure of existing vortex-induced vibration suppression device is complex, inconvenient to disassemble, not conducive to maintenance and high energy consumption, the application includes sleeve and multiple damping components, the sleeve is sleeved on riser and is detachably connected with riser, multiple damping components are evenly distributed along the circumferential direction and are installed on the outer periphery of sleeve, the sleeve includes two semicircular sleeves, and the two semicircular sleeves are clamped on the outer wall of the riser by a fixing member.The application has low energy consumption and low dependence on the riser device itself, without additional complexity of the system, through the design of two semicircular sleeves, the sleeve can be quickly installed and disassembled, and the application can be used immediately after installation, which is convenient to install and easy to maintain, and has wide applicability and high adaptability to vibration suppression problems of different engineering equipment.The application relates to the field of vortex-induced vibration suppression.

Description

Technical Field

[0001] This invention relates to the field of vortex-induced vibration suppression technology, specifically to an active marine riser vortex-induced vibration suppression device based on vibration-damping fins. Background Technology

[0002] Vortex-induced vibration (VIV) is a common phenomenon of structural vibration under fluid influence, widely found in marine engineering, aerospace, and bridge construction. With the increasing scale of engineering projects and the growing complexity of environmental conditions, VIE poses a serious challenge to the safety and stability of structures, making the development of efficient active vibration suppression devices particularly important. Currently, commonly used VIE suppression devices can be mainly classified into the following categories: 1. Passive devices that absorb vibration energy by adding dampers, but this method is usually unable to cope with complex multi-frequency excitation situations; 2. Methods such as shape optimization to change the flow field distribution on the structural surface to weaken VIE, but this method suffers from long design cycles and high costs; 3. Active vibration suppression devices based on electromagnetic, hydraulic, or piezoelectric principles, which can achieve high control accuracy, but existing devices often suffer from high energy consumption, slow response speed, and complex installation and maintenance.

[0003] There are many methods for actively suppressing vortex-induced vibration, but research on active vibration suppression devices that are widely applicable, easy to use, readily available, and easy to maintain is limited. Existing active vortex-induced vibration suppression structures are complex in design, consume a lot of energy, and are highly dependent on the riser itself. Structurally, most employ an external sleeve mounted on the riser with rotating components on it, making installation and disassembly inconvenient, and generating additional resistance during rotation. For example, publication number CN111306148 B describes a vortex-induced vibration suppression device for marine risers.

[0004] Therefore, developing an efficient, low-energy-consumption, and easy-to-maintain active marine riser vortex-induced vibration suppression device remains a pressing problem in the engineering field. Summary of the Invention

[0005] To address the problems of complex structure, inconvenient disassembly and assembly, poor maintenance, and high energy consumption of current vortex-induced vibration suppression devices, this invention proposes an active marine riser vortex-induced vibration suppression device based on vibration-damping fins.

[0006] The technical solution adopted by the present invention to solve the above problems is as follows:

[0007] The present invention includes a sleeve and multiple vibration damping components. The sleeve is fitted onto the riser and is detachably connected to the riser. The multiple vibration damping components are evenly distributed around the outer periphery of the sleeve in a circumferential direction. The sleeve includes two semi-circular sleeves, which are clamped to the outer wall of the riser by fasteners.

[0008] Furthermore, each of the vibration damping components includes a damping fin, a bearing, a fixed rotating shaft, two first connecting parts, a servo motor, and a second connecting part. The two first connecting parts are vertically arranged and opposite to each other. The lower end of each first connecting part is fixedly connected to the outer wall of the sleeve, and the upper end is rotatably connected to the side wall of the damping fin. The bearing, the fixed rotating shaft, the servo motor, and the second connecting part are all located inside the damping fin. A servo motor is installed at each end of the second connecting part. The output end of the servo motor is fixedly connected to one end of the fixed rotating shaft, and the other end of the fixed rotating shaft is connected to the inner side of the upper end of the first connecting part through the bearing.

[0009] Furthermore, the bearing is installed at the junction of the damping fin and the first connecting member. The outer diameter of the bearing is the same as the size of the side wall opening of the damping fin, and the inner diameter of the bearing is the same as the diameter of the fixed rotating shaft.

[0010] Furthermore, the second connector is a circular tube, and the second connector is integrated with the servo motors at both ends.

[0011] Furthermore, each semi-circular tube sleeve has connecting lugs at its two connecting ends.

[0012] Furthermore, sensors and embedded PID controllers are installed on the inner wall of the sleeve.

[0013] The beneficial effects of this invention are:

[0014] 1. This invention has low energy consumption and low dependence on the riser device itself, and will not add extra complexity to the system. Through the design of two semi-circular pipe sleeves, the pipe sleeves can be quickly installed and disassembled, making it ready to use immediately. It is easy to install, easy to maintain, and has a wide range of applications. It has high adaptability to vibration suppression problems of different engineering equipment.

[0015] 2. In this invention, the servo motor body is connected to the inner wall of the damping fin through the second connector, thereby transmitting the control motion of the servo motor and realizing the rotational motion of the damping fin around the fixed axis. The damping fins installed around the tube sleeve can be aligned with the flow from different directions in the plane, and then achieve the optimal angle of attack for each direction without causing additional resistance.

[0016] 3. The present invention provides a bearing at the junction of the damping fin and the first connecting member, which can ensure the water tightness of the device and avoid direct connection between the fixed rotating shaft and the damping fin, thereby hindering the rotation of the damping fin itself.

[0017] 4. The vibration suppression effect of this invention has been verified by relevant numerical simulations. After obtaining a large amount of training data, by combining it with the PID control method, the vibration reduction fin rotation control can be made in real time to monitor the movement of the riser, so as to achieve the best vibration suppression effect without bringing additional resistance. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the vibration damping fin structure;

[0020] Figure 3 yes Figure 2 A magnified view of a portion of the image;

[0021] Figure 4 This is a schematic diagram of the casing's assembly.

[0022] Figure 5 This is a schematic diagram of the assembly of the invention with the riser pipe;

[0023] Figure 6 It is the rotatability of the vibration damping fins;

[0024] Figure 7 This is a schematic diagram of the numerical model of the present invention;

[0025] Figure 8 The figure shows a comparison of the vibration suppression effect of the numerical model under different working conditions. Detailed Implementation

[0026] This embodiment describes an active marine riser vortex-induced vibration suppression device based on vibration-damping fins, such as... Figure 1 As shown, the device includes a sleeve 7 and multiple vibration damping components. The multiple vibration damping components are evenly distributed around the outer periphery of the sleeve 7 along the circumferential direction. The sleeve 7 includes two semi-circular sleeves 10, as shown... Figure 4 As shown, the two semi-circular sleeves 10 are detachably connected to the riser 8 via fasteners. Each semi-circular sleeve 10 has connecting lugs 9 at both ends. Bolts are passed through the connecting lugs 9 of the two semi-circular sleeves 10 in sequence and then fixed with nuts to clamp the two semi-circular sleeves 10 onto the riser 8.

[0027] like Figure 2 , Figure 3 As shown, each vibration damping component includes a damping fin 1, a bearing 2, a fixed rotating shaft 3, two first connecting parts 4, a servo motor 5, and a second connecting part 6. The two first connecting parts 4 are vertically arranged and opposite to each other. The first connecting parts 4 are two connecting rods of a certain length, with their lower ends welded and fixed to the outer wall of the sleeve 7, and their upper ends rotatably connected to the damping fin through the fixed rotating shaft 3 and the bearing 2. The bearing 2, the fixed rotating shaft 3, the servo motor 5, and the second connecting part 6 are all located inside the damping fin 1. The second connecting part 6 is fixedly connected to the damping fin 1. A servo motor 5 is provided at each end of the second connecting part 6. The output end of the servo motor 5 is fixedly connected to one end of the fixed rotating shaft 3, and the other end of the fixed rotating shaft 3 is connected to the inner side of the upper end of the first connecting part 4 through the bearing 2.

[0028] Preferably, the servo motor 5 is connected to a second connector 6, which is connected to the damping fin 1 to transmit the control motion of the servo motor 5 and realize the rotational motion of the damping fin 1 around a fixed axis. The damping fins around the servo motor 5 can be aligned with the flow from different directions in the plane and achieve the optimal angle of attack for each direction without causing additional resistance.

[0029] The fixed rotating shaft 3 and the motor shaft of the servo motor 5, the second connecting piece 6 and the inner wall of the damping fin 1, and the bearing 2 and the side wall 1 of the damping fin are all connected by an interference fit between the shaft diameters, which makes the installation and operation more convenient.

[0030] Preferably, the second connector 6 is a circular tube, which is integrated with the body of the servo motor 5 at both ends. The lower end of the fixed rotating shaft 3 has a hole of the same size as the motor shaft of the servo motor 5, which can achieve a tight connection between the two and ensure that the motor shaft remains static when the servo motor is working, while the body is in a dynamic rotational state relative to the fixed rotating shaft 3 and the motor shaft under the control signal of the servo motor.

[0031] Preferably, considering the watertightness of the device and the fact that the fixed rotating shaft 3 and the damping fin 1 cannot be directly connected to avoid hindering the rotation of the damping fin itself, a bearing 2 is provided at the junction of the damping fin 1 and the first connecting member 4. The outer diameter of the bearing 2 is the same as the size of the opening of the damping fin 1, and the inner diameter is the same as the diameter of the fixed rotating shaft 3.

[0032] Preferably, a sensor and an embedded PID are installed on the inner wall of the sleeve 7. The sensor and the embedded PID can monitor the vibration state of the riser in real time, realize the monitoring of riser motion-related data and the calculation of control signals, and output them to the servo motor 5 system. In turn, they control the rotation of the vibration damping fins 1 around the sleeve 7 to change the vortex shedding mode, reduce the lift resistance of the riser, and achieve the effect of suppressing vibration without bringing additional resistance.

[0033] Working principle:

[0034] When the incoming flow acts on the riser 8, the riser 8 experiences vortex-induced vibration. The half-pipe sleeve 10 is bolted to the riser 8, and thus vibrates. Sensors and an embedded PID controller are installed inside the sleeve 7. These sensors measure the motion of the riser 8, including its acceleration, velocity, and displacement. By analyzing this data, the vibration state of the riser is monitored in real time. Combined with the embedded PID controller, rapid control of the servo motor 5 system can be achieved. By rotating the damping fins 1 around the sleeve 7, the vortex shedding mode is changed, reducing the lift resistance on the riser and thus suppressing vibration.

[0035] This invention differs from traditional active vibration controllers and active flow field control devices. This active vibration suppression device has low energy consumption and is less dependent on the riser device itself. It does not add extra complexity to the system, can be used immediately after installation, is easy to install and maintain, and has a wide range of applications. It is highly adaptable to vibration suppression problems of different engineering equipment.

[0036] This invention features simple structure, simple technology, easy installation, real-time monitoring and adjustment, good vibration suppression effect, and wide applicability. Numerical simulations have proven that the rotation of the vibration-damping fins around the pipe sleeve under PID control can effectively reduce vortex-induced vibration of the riser pipe. The numerical model is as follows: Figure 7 As shown in the figure. The computational domain of this numerical model is 40D×20D, and the origin of the computational domain is set at the center of the circle. The left boundary is 10D from the origin and is set as the velocity inlet; the right boundary is 30D from the origin and is set as the pressure outlet; the upper and lower boundaries are each 10D from the origin and are set as wall conditions. Four damping fins H1, H2, H3 and H4 are distributed clockwise around the circumference of the circle. To demonstrate the feasibility and effectiveness of this vibration damping device, two calculation conditions as shown in Table 1 were set, and the results are as follows. Figure 8 The comparison diagram of vibration suppression effects is shown. It can be seen that the vibration suppression efficiency of this numerical model can reach over 90% under both different working conditions, demonstrating excellent vibration suppression capability.

[0037] In the vibration damping device, K is achieved by combining PID control with extensive experimentation and error-based training. p K i and K d By setting the optimal combination of parameters, the vibration damping fins are controlled in real time based on the monitored riser velocity, acceleration, and displacement data, achieving the best vibration suppression effect. This device, as an active marine riser vortex-induced vibration suppression device based on vibration damping fins, greatly facilitates the installation and disassembly of the device and effectively suppresses riser vortex-induced vibration.

[0038] Table 1. Numerical Model Calculation Conditions

[0039]

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. An active marine riser vortex-induced vibration suppression device based on vibration-damping fins, the device comprising a sleeve (7) and multiple vibration-damping components, the sleeve (7) being fitted onto and detachably connected to the riser (8), the sleeve (7) comprising two semi-circular sleeves (10), the two semi-circular sleeves (10) being clamped to the outer wall of the riser (8) by fasteners; characterized in that: Multiple vibration damping components are evenly distributed around the outer periphery of the sleeve (7) along the circumferential direction. Each vibration damping component includes a damping fin (1), a bearing (2), a fixed rotating shaft (3), two first connecting parts (4), a servo motor (5), and a second connecting part (6). The two first connecting parts (4) are vertically arranged and opposite to each other. The lower end of each first connecting part (4) is fixedly connected to the outer wall of the sleeve (7), and the upper end is rotatably connected to the side wall of the damping fin (1). The bearing (2), the fixed rotating shaft (3), the servo motor (5), and the second connecting part (6) are all located inside the damping fin (1). A servo motor (5) is installed at each end of the second connecting part (6). The output end of the servo motor (5) is fixedly connected to one end of the fixed rotating shaft (3), and the other end of the fixed rotating shaft (3) is connected to the inner side of the upper end of the first connecting part (4) through the bearing (2). By aligning the vibration damping components installed around the sleeve (7) with the flow in different directions in the plane, the optimal angle of attack state is achieved.

2. The active marine riser vortex-induced vibration suppression device based on damping fins according to claim 1, characterized in that: The bearing (2) is installed at the junction of the damping fin (1) and the first connecting member (4). The outer diameter of the bearing (2) is the same as the size of the side wall opening of the damping fin (1), and the inner diameter of the bearing (2) is the same as the diameter of the fixed rotating shaft (3).

3. The active marine riser vortex-induced vibration suppression device based on damping fins according to claim 2, characterized in that: The second connector (6) is a circular tube, and the second connector (6) is connected to the servo motors (5) at both ends as one unit.

4. The active marine riser vortex-induced vibration suppression device based on damping fins according to claim 3, characterized in that: Each semi-circular sleeve (10) has a connecting ear plate (9) at each of its two connecting ends.

5. The active marine riser vortex-induced vibration suppression device based on damping fins according to claim 1, characterized in that... The feature is that a sensor and an embedded PID are installed on the inner wall of the sleeve (7).

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