Arc-shaped bent plate passive control device for reducing damage of flow field to submarine cable

Abstract

The invention discloses an arc-shaped bent plate passive control device for reducing the damage of a flow field to a submarine cable. The device comprises a set of front bent plates and a set of rear bent plates, the front bent plates and the rear bent plates are installed on a pipeline in a segmented mode, the front bent plates are installed in the direction, right facing the incoming flow, of the pipeline, the rear bent plates are installed in the direction, back to the incoming flow, of the pipeline, and the center positions of the front bent plates and the center positions of the rear bent plates are kept consistent with a horizontal shaft. The front bent plate and the rear bent plate are symmetrical about the horizontal axis. The arc-shaped bent plate is installed outside the pipeline, the fluid streaming path can be effectively changed, then the resistance and lifting force effects of fluid on the pipeline are reduced, and through application of the arc-shaped bent plate, the overall efficiency of a pipeline system can be improved. Particularly in a uniform flow field, the device can remarkably reduce pressure and friction force borne by the surface of the pipeline, vibration and fatigue of the pipeline are reduced, and therefore the service life of the pipeline is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of submarine pipeline and cable protection, and in particular relates to an arc-shaped bent plate passive control device for reducing damage to submarine cables caused by flow fields. Background Art

[0002] The complex fluid flows and strong ocean currents in the marine environment will produce significant friction and pressure on the surface of the submarine pipeline. These flows and ocean currents will not only increase the energy consumption of the fluid when passing through the pipeline, but may also cause a series of potential problems, such as uneven force on the pipeline and local stress concentration, which may cause the pipeline to shift, deform, and even structural damage in extreme cases. Long-term friction and pressure will also accelerate the wear of the pipeline material and shorten the service life of the pipeline.

[0003] In order to meet these challenges, the resistance of ocean currents to pipelines can be greatly reduced through effective external drag reduction design and technology. These technologies can significantly reduce the impact and friction of the fluid on the outer surface of the pipeline without affecting the structural strength of the pipeline, thereby reducing the wear rate, reducing stress concentration on the pipeline, and improving the safety and stability of the overall structure. At the same time, external drag reduction technology can also reduce energy consumption, making the operation of marine pipelines more economical. In addition, while reducing fluid resistance, drag reduction design can also reduce potential threats to marine ecosystems caused by changes in pipeline position or damage. Therefore, the research and application of external drag reduction technology for marine pipelines is not only of far-reaching significance for improving the feasibility and economy of deep-sea engineering, but also more effectively ensures the stability and safety of submarine energy transportation.

[0004] In the past few decades, research on cylinder flow control has made significant progress. This is because flow control has a wide range of practical applications in reducing the hydrodynamic load of pipeline structures, suppressing vortex-induced vibrations, and even harvesting energy from marine fluids. Cylinder flow control methods can generally be divided into three categories: the first category is passive control, which does not require power input and relies on the design of the structure itself to change the flow characteristics; the second category is active open-loop control, which involves actuators with power input but no sensor feedback; the third category is active closed-loop control, which requires sensors to monitor the flow field in real time and feedback control through actuators with power input.

[0005] Among these three methods, passive control is relatively more efficient and easy to implement because it does not rely on external power input or complex sensor systems, so it has great advantages in practical applications. Previous studies have shown that designing specific geometric structures on the cylindrical surface, such as V-shaped grooves, U-shaped grooves, square grooves or pits, can achieve significant drag reduction effects at high Reynolds numbers. These surface structures effectively reduce the friction resistance and turbulence intensity of the surface by changing the distribution and flow path of the fluid on the surface. However, although these designs have shown good drag reduction effects in experiments, the molds required for their molding are complex, difficult to manufacture and expensive, which limits their large-scale industrial applications.

[0006] Therefore, future research may need to find a balance between drag reduction effect, manufacturing cost and structural complexity to develop a more economical, practical and efficient external drag reduction solution, which will have a profound impact on the design and operation of submarine pipeline engineering and other marine structures. Summary of the invention

[0007] The purpose of the present invention is to provide an arc-shaped bent plate passive control device for reducing flow field damage to submarine cables, which can significantly reduce the pressure and friction on the pipeline surface, reduce pipeline vibration and fatigue, and thus extend the service life of the pipeline.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] A passive control device for arc-shaped bent plates for reducing damage to submarine cables caused by flow fields, comprising: a group of front bent plates and a group of rear bent plates, wherein the front bent plates and the rear bent plates are installed on pipelines in sections, wherein the front bent plates are installed on the pipeline facing the incoming flow direction, and the rear bent plates are installed on the pipeline facing away from the incoming flow direction, wherein the center positions of the front bent plates and the rear bent plates are consistent with a horizontal axis, and the front bent plates and the rear bent plates are symmetrical about the horizontal axis.

[0010] Furthermore, the arc length (θ f ,θ b ) range is 80-100°.

[0011] Furthermore, the arc length (θ f ,θ b ) range is 80-100°.

[0012] Furthermore, the thickness d of the front bent plate is 0.1-0.2 times the diameter D of the pipe.

[0013] Furthermore, the thickness d of the rear bent plate is 0.1-0.2 times the diameter D of the pipe.

[0014] Furthermore, the distance between the front bent plate and the rear bent plate is 4-8 times the diameter of the pipe.

[0015] Furthermore, the length of the front bent plate is 3-5 times the diameter D of the pipe.

[0016] Furthermore, the length of the rear bent plate is 3-5 times the diameter D of the pipe.

[0017] The beneficial effects of the present invention are:

[0018] The present invention has the advantages of simple structure, convenient manufacturing, low cost, etc., and is suitable for wide application in practical engineering. By installing an arc-shaped bent plate outside the pipeline, the fluid flow path can be effectively changed, thereby reducing the resistance and lift effect of the fluid on the pipeline.

[0019] The present invention can significantly reduce the pressure and friction on the pipeline surface, reduce pipeline vibration and fatigue, and thus extend the service life of the pipeline, especially under a uniform flow field. At the same time, since the device does not require a complex electric drive and sensor system, as a passive control method, it is not only energy-saving and environmentally friendly, but also has low maintenance costs and is suitable for various marine and land pipeline projects.

[0020] The present invention not only improves the overall efficiency of the pipeline system through the application of the arc-shaped bent plate, but also reduces the total cost of pipeline construction and operation to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Attached Figure 1 It is a structural schematic diagram of the present invention.

[0022] Attached Figure 2 It is a cross-sectional view of the present invention.

[0023] Attached Figure 3 It is a comparative schematic diagram of the drag reduction effect of the present invention.

[0024] Attached Figure 4 It is a schematic diagram of the structure of the present invention during segmented installation.

[0025] In the attached drawings: 1. front bent plate, 2. rear bent plate, 3. pipe. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0029] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps described in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0030] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", etc. are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0031] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0032] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0033] The present invention is further described below in conjunction with the accompanying drawings.

[0034] The present invention provides a passive control device for arc-shaped curved plates for reducing the damage of flow fields to submarine cables, which comprises: a group of front curved plates 1, a group of rear curved plates 2, as shown in the attached figure. Figure 1 As shown, the front bend plate 1 and the rear bend plate 2 are installed in sections on the pipe 3, the front bend plate 1 is installed on the pipe 3 facing the incoming flow direction, and the rear bend plate 2 is installed on the pipe 3 facing away from the incoming flow direction. The center positions of the front bend plate 1 and the rear bend plate 2 are consistent with the horizontal axis, and the front bend plate 1 and the rear bend plate 2 are symmetrical about the horizontal axis.

[0035] As attached Figure 2 As shown, the arc length (θ f ,θ b ) range is 80-100°.

[0036] The thickness d of the front curved plate 1 and the rear curved plate 2 is approximately 0.1 to 0.2 times of the diameter, which can ensure the drag reduction effect while minimizing the impact on the original structure of the pipeline.

[0037] As attached Figure 1-2 As shown, the front curved plate 1 and the rear curved plate 2 can be fixed on the pipe 3 through a specific structure or directly. The center positions of the front curved plate 1 and the rear curved plate 2 are consistent with the horizontal axis (water flow direction), that is, the entire structure is always symmetrical about the horizontal axis. Figure 3As shown in the figure, the small vortex formed at the angle between the front curved plate 1 and the cylinder of the present invention reduces the viscous force of the front edge of the groove, and further reduces the drag coefficient caused by viscous friction. In addition, these small vortices can also promote the adhesion of the fluid, increase the pressure of the cylindrical groove part, and then reduce the pressure difference in the vertical direction, thereby reducing the lift force on the cylinder.

[0038] As attached Figure 3 As shown, (a) is a schematic diagram of the drag reduction effect when the pipe is not equipped with a bent plate, and (b) is a schematic diagram of the drag reduction effect when the bent plate is installed in this embodiment. The present invention reduces the width of the wake field by controlling the fluid separation point at the sharp corner of the rear bent plate, thereby reducing the drag coefficient induced by the pressure difference before and after the cylinder.

[0039] As attached Figure 4 As shown, this embodiment adopts a segmented installation method, that is, the bent plate structure is installed on the pipeline structure in a segmented form. Compared with the integral bent plate design, the segmented installation can not only significantly reduce the material cost, but also improve the flexibility and efficiency of construction. Through the segmented installation method, the length and position of the bent plate can be accurately controlled according to actual needs to achieve the best fluid control effect.

[0040] The present invention can also optimize the structure according to different fluid conditions and engineering requirements by reasonably designing and adjusting the span of the bent plates and the spacing between the bent plates, thereby further improving the drag reduction effect and overall performance.

[0041] Preferably, this embodiment can also adopt a segmented installation method to meet different design requirements. Specifically, the bent plate can be installed on the cylindrical structure in segments according to a certain spacing and a specific length, similar to the installation method of a single device.

[0042] Preferably, the distance between adjacent front curved plates and rear curved plates is controlled to be 4-8 times of the pipe diameter D, and the length of the curved plates is controlled to be about 3-5 times of the pipe diameter D, preferably 3 times. According to actual needs, these parameters can be appropriately adjusted to achieve the best drag reduction and shock absorption effect.

[0043] By adopting the technical solution of the above embodiment, the present invention can effectively utilize the vortex dislocation mechanism to reduce the lift force on the cylinder. When the fluid bypasses the segmented curved plates, the spacing between the curved plates will cause the generated vortex to be dislocated, so that the mutual interference of the vortices is enhanced, thereby weakening the vertical force of the fluid on the pipeline, and ultimately greatly reducing the lift force.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A passive control device for arc-shaped curved plates for reducing the damage of flow fields to submarine cables, characterized in that: include: A group of front curved plates (1) and a group of rear curved plates (2), wherein the front curved plates (1) and the rear curved plates (2) are installed on a pipe (3) in sections, wherein the front curved plates (1) are installed on the pipe (3) facing the incoming flow direction, and the rear curved plates (2) are installed on the pipe (3) facing away from the incoming flow direction, wherein the center positions of the front curved plates (1) and the rear curved plates (2) are consistent with a horizontal axis, and the front curved plates (1) and the rear curved plates (2) are symmetrical about the horizontal axis.

2. The arc-shaped bent plate passive control device for reducing flow field damage to submarine cables according to claim 1, characterized in that: The arc length (θ f ,θ b ) range is 80-100°.

3. The arc-shaped bent plate passive control device for reducing flow field damage to submarine cables according to claim 1, characterized in that: The arc length (θ f ,θ b ) range is 80-100°.

4. The arc-shaped bent plate passive control device for reducing flow field damage to submarine cables according to claim 1 or 2, characterized in that: The thickness d of the front bent plate (1) is 0.1-0.2 times the diameter D of the pipe (3).

5. The arc-shaped bent plate passive control device for reducing flow field damage to submarine cables according to claim 1 or 3, characterized in that: The thickness d of the rear bent plate (2) is 0.1-0.2 times the diameter D of the pipe (3).

6. The arc-shaped bent plate passive control device for reducing flow field damage to submarine cables according to claim 1, characterized in that: The distance between the front bent plate (1) and the rear bent plate (2) is 4 to 8 times the diameter of the pipe (3).

7. The arc-shaped bent plate passive control device for reducing flow field damage to submarine cables according to claim 1, characterized in that: The length of the front bent plate (1) is 3-5 times the diameter D of the pipe (3).

8. The arc-shaped bent plate passive control device for reducing flow field damage to submarine cables according to claim 1, characterized in that: The length of the rear bent plate (2) is 3-5 times the diameter D of the pipe (3).

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