Double-arc built-in moon pool box type floating breakwater

Abstract

The present application relates to the technical field of coastal and offshore engineering, in particular to a double-arc built-in moon pool box type floating breakwater. The breakwater is internally provided with a square moon pool penetrating in the vertical direction, which separates the box structure into front and rear symmetrical front and rear floating boxes. The front floating box is located on the wave-encountering side of the floating box main body, and the rear floating box is located on the wave-encountering side. The wave-encountering side of the front floating box is provided with a circular arc-shaped wave-converging plate, which is connected with the front floating box structure to form a vertically recessed arc-shaped structure. A plurality of flow guide holes penetrating from the wave-encountering side to the moon pool are arranged at the vertical center position of the structure, and the flow guide holes are equidistantly arranged from top to bottom with the same hole diameter. The wave-encountering side of the rear floating box is provided with an arc-shaped wave guide plate, which is in the form of a semi-cylindrical shape and is connected with the wave-encountering side of the rear floating box to form a horizontally recessed arc-shaped structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coastal and offshore engineering, in particular to a double-arc built-in moon pool box type floating breakwater. BACKGROUND

[0002] With the rapid development of social economy, land resources and space have been difficult to meet the needs of social development, and resource development gradually shifts from land to ocean. With the increasing demand for marine resource development around the world, various types of marine infrastructure have been put into use, which greatly promotes the rapid development of marine industry. Especially in the fields of oil, natural gas, fishery resources and offshore wind power. However, the marine environment is complex and changeable, and extreme weather and natural disasters occur frequently, making the safety problem of marine structures more serious. In the deep sea area, wind, wave, tide and extreme weather conditions pose great challenges to the structural stability and safety of marine facilities.

[0003] To meet this challenge, floating breakwater as a new type of offshore protection structure has been widely used in many fields. Floating breakwater is stable through buoyancy and appropriate anchoring system, does not need to be fixed to the seabed, and achieves wave attenuation by changing the wave propagation path. It can effectively resist large waves and storms, while maintaining water exchange and avoiding water quality deterioration. However, the application of floating breakwater is still limited at present, mainly due to the complexity of deep sea environment. When the wave height is large, overtopping phenomenon is easy to occur; when the wave period is long, the wave attenuation effect of the breakwater is significantly reduced. In order to improve the wave attenuation effect, the width of the floating breakwater needs to be increased, resulting in the increase of construction cost. In addition, under extreme wave conditions, the floating breakwater itself may be damaged.

[0004] In summary, it is a key technical problem to be solved in the field of coastal and offshore engineering to develop a double-arc built-in moon pool box type floating breakwater with light and stable structure, optimized cost and high-efficiency wave attenuation and flow reduction function. SUMMARY

[0005] To solve the problems in the prior art, the application provides a double-circular-arc built-in moon pool box type floating breakwater, which has good attenuation effect on long-period waves, is easy to process, is convenient to install, is economical and has wide applicability. The breakwater is internally provided with a square moon pool penetrating in the vertical direction, the moon pool divides the box body structure into front and rear symmetrical front and rear floating boxes, the front floating box is located on the wave-encountering side of the floating box main body, the rear floating box is located on the wave-encountering side, the wave-encountering side of the front floating box is provided with a circular-arc shaped wave collecting plate, the wave collecting plate and the front floating box structure are nested and connected to form an inner concave arc structure in the vertical direction, a plurality of flow guide holes penetrating from the wave-encountering side to the moon pool are arranged at the vertical center position of the structure, the flow guide holes are equidistantly arranged from top to bottom, and the opening diameters are the same; the wave-encountering side of the rear floating box is provided with an arc-shaped wave guide plate, the wave guide plate is in a semi-cylindrical shape, is nested and connected with the wave-encountering side of the rear floating box to form an inner concave arc structure in the horizontal direction.

[0006] To achieve the above object, the application provides the following technical scheme.

[0007] A double-circular-arc built-in moon pool box type floating breakwater, comprising a floating box main body 1, a moon pool 2, a wave collecting plate 3 and a wave guide plate 4.

[0008] The moon pool 2 is located in the middle of the floating box main body 1, penetrates the floating box main body 1 in the vertical direction, and divides the floating box main body 1 into the front and rear floating boxes 10 and 11 arranged symmetrically; the front floating box 10 is located on the wave-encountering side of the floating box main body 1, and the rear floating box 11 is located on the wave-encountering side of the floating box main body 1.

[0009] The wave-encountering side of the front floating box 10 is provided with a shallow dome-shaped arc surface arranged in the vertical direction, and the same size and type of the wave collecting plate 3 is fixed on the arc surface.

[0010] The wave-encountering side of the rear floating box 11 is provided with a semi-cylindrical arc surface arranged in the horizontal direction, and the same size and type of the wave guide plate 4 is fixed on the arc surface.

[0011] The part of the floating box main body 1 between the wave collecting plate 3 and the moon pool 2 is internally provided with a plurality of penetrating and horizontally arranged flow guide holes 5, the water inlet end of the flow guide hole 5 is located on the windward side of the front floating box 10, and the water outlet end is located on the inner wall of the moon pool 2 close to the wave-encountering side.

[0012] The chord length of the wave collecting plate 3 is 1 / 10-1 / 15 of the incident wavelength L of the sea wave, and the arch height is 1 / 4 of the chord length; the moon pool 2 is a rectangular opening, is arranged symmetrically in the middle of the floating box main body 1, the inner cavity length of the moon pool 2 is 1 / 15-1 / 20 of the incident wavelength L of the sea wave, and the width is 2 / 3 of the cavity length; the hole diameter of the flow guide hole 5 is 1 / 3-1 / 5 of the incident wave height H of the sea wave; the arc radius of the wave guide plate 4 is equal to the arch height of the wave collecting plate 3.

[0013] The top surface and the bottom surface of the front floating box 10 corresponding to the space of the shallow arch body where the wave-accumulating plate 3 is located are respectively used as the first wing plate 6 and the second wing plate 7; the opening direction of the wave-accumulating plate 3 is the front direction, and the two side surfaces of the front floating box 10 corresponding to the space in front of the wave-accumulating plate 3 are respectively used as the first rib plate 8 and the second rib plate 9; the thicknesses of the first wing plate 6 and the second wing plate 7 are the same; and the thicknesses of the first rib plate 8 and the second rib plate 9 are the same.

[0014] The top surface and the bottom surface of the rear floating box 11 corresponding to the space of the semi-cylindrical body where the wave-guiding plate 4 is located are respectively used as the third wing plate 12 and the fourth wing plate 13; the opening direction of the wave-guiding plate 4 is the front direction, and the two side surfaces of the rear floating box 11 corresponding to the space in front of the wave-guiding plate 4 are respectively used as the third rib plate 14 and the fourth rib plate 15; the thicknesses of the third wing plate 12 and the fourth wing plate 13 are the same; and the thicknesses of the third rib plate 14 and the fourth rib plate 15 are the same.

[0015] The floating box body 1, the wave-accumulating plate 3 and the wave-guiding plate 4 are integrally manufactured from the composite polyethylene material.

[0016] The present application has the following beneficial effects:

[0017] 1. The present application realizes significant wave reduction and structural stability effect through innovative structural design and fluid dynamics optimization. The core innovation is that the wave-accumulating plate and the wave-guiding plate are both set as concave arc plates, and a through moon pool is arranged in the central part of the box body, forming a complete multi-stage wave energy dissipation system.

[0018] 2. The present application uses the wave-accumulating effect of the concave arc surface on the wave-accumulating plate to efficiently converge the incident wave energy to the moon pool entrance area, realizing directional guidance and pre-dissipation of energy in the initial stage of wave incidence. The moon pool structure is used as a core energy conversion unit, and the strong vortex and turbulent mixing effect of the high-speed water flow formed by the horizontally arranged flow guide holes is used to convert wave kinetic energy into turbulent energy and dissipate it. The concave arc surface on the wave-guiding plate, i.e. the wave-guiding plate structure, implements secondary regulation on the transmitted wave energy, further weakens the remaining wave energy through induced reverse vortex and phase interference effect. The structure forms a three-stage energy dissipation mechanism composed of wave-accumulating flow guide, turbulent dissipation and phase interference, which still maintains excellent wave reduction performance under wide frequency wave conditions.

[0019] 3. The special structural design of the present application can bring significant engineering application advantages. The symmetrical arrangement of the double concave arc surfaces enhances the self-balancing ability of the structure, which can effectively suppress the common pitching and surging phenomena of traditional breakwaters. The through design of the moon pool not only optimizes the fluid exchange, but also provides additional buoyancy reserve for the structure. The modular characteristics of the whole system make it flexible to adapt to different sea environment and wave conditions, and has broad application prospects in the fields of port engineering, deep sea fishery culture, etc.

[0020] 4、When the double-arc-surface built-in moon-pool box-type floating breakwater is in working state, the oncoming wave interacts with the wave-accumulating plate structure, part of the wave is reflected and attenuated, and part of the wave is injected into the moon-pool cavity through the flow guide hole, so as to realize wave attenuation. The wing plates at the upper and lower ends of the windward surface of the front floating box can guide more waves to the water inlet end of the flow guide hole, and enhance the inhibition of the transverse movement of water particles in the wave, thereby reducing the transmission coefficient. The wave-accumulating plate structure can force the wave crest to break ahead of time, move the breaking position forward, and reduce the direct load on the box. The wave guide plate promotes wave breaking and energy dissipation through wave impact effect, so as to achieve the effect of wave dissipation. At the same time, the concave reflection wave and the moon-pool transmission wave form an approximately anti-phase interference effect, further reducing the wave height on the back side. The unique pressure distribution on the back side produces a stable effect similar to "suction effect", effectively inhibiting the amplitude of the longitudinal swing of the structure.

[0021] 5、Compared with the traditional square box-type floating breakwater, the double floating box structure can increase the longitudinal inertia moment, reduce the model motion response, reduce the mooring cable tension, and improve the running stability. The moon-pool structure formed in the middle of the double floating box, the internal fluid movement exists piston mode and sloshing mode. When the wave incidence period is close to the natural period of the moon-pool movement mode, resonance occurs inside the moon-pool, effectively dissipating the incident wave energy; when the periods are different, the fluid in the moon-pool reflects multiple times, leading to strong nonlinear phenomena such as wave breaking and splashing, further improving the wave energy dissipation effect. At the same time, the movement of the floating breakwater will further intensify the fluid movement inside the moon-pool, thereby more effectively dissipating the incident wave energy.

[0022] 6、During the wave incidence process, the incident wave is guided to the center of the arc-shaped plate, and then enters the flow guide hole. The water flow hits the inner wall of the moon-pool of the rear floating box, and then dissipates the incident wave energy. The impulse given to the inner wall during the injection process reduces the model motion and reduces the mooring cable tension.

[0023] 7、During the downward movement of the floating box main body, the back wave surface arc-shaped wave guide plate moves with the floating breakwater, driving the water particles above downward. Due to the fact that the water particles behind the breakwater cannot be replenished in time, an air gap with a liquid surface lower than the average free liquid surface is formed above the back wave surface airfoil structure. Under the action of water pressure difference, the water particles behind will flow in the opposite direction and hit the back wall of the back wave surface arc-shaped plate, causing wave impact breaking and dissipating part of the wave energy. BRIEF DESCRIPTION OF DRAWINGS

[0024] Fig. 1 is the front view of the double-arc-surface built-in moon-pool box-type floating breakwater structure of the present application;

[0025] Fig. 2 is the side view of the double-arc-surface built-in moon-pool box-type floating breakwater structure of the present application;

[0026] Fig. 3is a top view of a double-arc surface built-in moon pool box type floating breakwater according to the present application;

[0027] In the figure: 1 floating body, 2 moon pool, 3 wave converging plate, 4 wave guiding plate, 5 flow guiding hole, 6 first wing plate, 7 second wing plate, 8 first rib plate, 9 second rib plate, 10 front floating body, 11 rear floating body, 12 third wing plate, 13 fourth wing plate, 14 third rib plate, 15 fourth rib plate. DETAILED DESCRIPTION

[0028] The specific embodiments of the present application are further illustrated in combination with the accompanying drawings and technical solutions.

[0029] Reference Figs. 1 to 3 According to the double-arc surface built-in moon pool box type floating breakwater of the present application, it comprises a floating body 1, a moon pool 2, a wave converging plate 3, and a wave guiding plate 4.

[0030] Specifically, the floating body 1 has a moon pool 2 penetrating through the floating body 1 along the vertical direction, and the moon pool 2 divides the floating body 1 into a front floating body 10 and a rear floating body 11 which are symmetrically arranged in front of and behind the center line of the moon pool 2. The front floating body 10 is located on the windward side of the floating body 1, and the rear floating body 11 is located on the leeward side of the floating body 1. The front floating body 10 is internally provided with four flow guiding holes 5 penetrating through it, and the front floating body 10 has a windward surface on its front side. The water inlet end and the water outlet end of the flow guiding hole 5 are flush, and the water inlet end is located on the windward surface of the front floating body 10, and the water outlet end is located on the inner wall of the moon pool 2 near the wave-approaching side end. The rear floating body 11 has a leeward surface on its rear side, and the windward surface of the front floating body 10 and the leeward surface of the rear floating body 11 are symmetrically arranged in front of and behind the center line of the moon pool 2. The wave converging plate 3 is arranged on the windward surface of the front floating body 10, and is used for guiding the wave flow to the water inlet end of the flow guiding hole 5. The wave guiding plate 4 is arranged on the leeward surface of the rear floating body 11, and is arc-shaped.

[0031] In use, waves enter the moon pool 2 between the front float box 10 and the rear float box 11 to generate a moon pool effect, forming turbulence to dissipate energy. When the waves hit the windward side of the front float box 10, part of the waves is reflected and attenuated, and part of the waves enters the moon pool 2 cavity through the water inlet end of the flow guide hole 5 and is injected into the moon pool 2 cavity from the water outlet end. The high-speed jet flow impacts the inner wall of the cavity to excite the internal water body to generate intense turbulence, which in turn dissipates the kinetic energy of the incident waves into internal energy through the viscosity shear and friction of the water body and turbulence vortex, thereby achieving wave attenuation. At the same time, the flow dividing effect of the flow guide hole 5 reduces the wave impact force directly acting on the wave concentrating plate 3, optimizing the load distribution. In addition, the wave concentrating plate 3, the first wing plate 6 and the second wing plate 7 arranged on the windward side of the front float box 10 can guide the waves to the water inlet end of the flow guide hole 5, so that more wave energy is dissipated into internal energy, and the suppression effect on the transverse motion of water particles in the waves is enhanced, thereby reducing the wave transmission coefficient. Further, the wave guide plate 4 with an inner concave curved surface arranged on the leeward side of the rear float box 11 not only effectively improves the balance of the overall structure in water, but also further improves the wave attenuation effect by wave impact and fragmentation. The above structure enables the double-arc surface built-in moon pool box type floating breakwater of the embodiment of the present application to improve the attenuation effect on deep-sea, long-period waves.

[0032] Referring to Figs. 1 to 3 , the top surface and the bottom surface of the front float box 10 corresponding to the shallow arched body space where the wave concentrating plate 3 is located are respectively the first wing plate 6 and the second wing plate 7, and are located on the upper and lower sides of the water inlet end of the flow guide hole 5. With the opening direction of the wave concentrating plate 3 as the front, the two side surfaces of the front float box 10 corresponding to the space in front of the wave concentrating plate 3 are respectively the first rib plate 8 and the second rib plate 9. The first wing plate 6 and the second wing plate 7 not only force more waves to converge to the water inlet end of the flow guide hole 5, but also cause the waves to splash and dissipate energy after being blocked, thereby further enhancing the wave attenuation effect.

[0033] Referring to Figs. 1 to 3 , the top surface and the bottom surface of the rear float box 11 corresponding to the semicylindrical space where the wave guide plate 4 is located are respectively the third wing plate 12 and the fourth wing plate 13; with the opening direction of the wave guide plate 4 as the front, the two side surfaces of the rear float box 11 corresponding to the space in front of the wave guide plate 4 are respectively the third rib plate 14 and the fourth rib plate 15. When the overall structure is subjected to periodic pitching under wave impact, the third rib plate 14 and the fourth rib plate 15 can effectively increase the impact effect of the leeward side on the waves, promoting wave fragmentation. At the same time, periodic pitching causes the concave curved surface structure composed of the wave guide plate 4, the third rib plate 14 and the fourth rib plate 15 to periodically disturb the water surface, further forcing the waves to break and dissipate wave energy, thereby enhancing the attenuation effect.

[0034] It should be noted that in some other embodiments, the number of flow guide holes 5 can be adjusted as appropriate, and the inner diameter of the flow guide holes 5 can be adjusted according to sea conditions, which is not limited here.

[0035] The present application adopts a modular prefabricated structure, which can be manufactured in segments and assembled on site during construction, thereby greatly reducing transportation and installation costs. The coordinated design of the concave arc surface and the flow guide hole can reduce material usage, optimize load distribution, effectively extend service life, and reduce maintenance costs. The introduction of the moon pool 2 can enhance the overall buoyancy of the structure and reduce the dependence on expensive buoyancy materials. The Venturi effect of the flow guide hole 5 system can enhance the wave damping effect without additional energy consumption, making the entire system have excellent cost-benefit ratio in the life cycle.

[0036] In terms of wave damping and flow reduction performance, the present application can achieve excellent wave attenuation effect through a three-stage energy dissipation mechanism. The wave-encountering side wave-converging plate 3 first converges and pre-dissipates wave energy, the flow guide hole 5 converts part of the wave energy into a directional high-speed jet, the strong vortex motion in the moon pool 2 efficiently dissipates kinetic energy into turbulent energy, and finally the wave-encountering side wave-converging plate 4 completes the secondary reduction of the remaining energy through vortex interference and slamming and breaking. This multi-stage energy dissipation system enables the breakwater to adapt to a wide spectrum of waves from short to long periods, maintaining stable wave damping performance in various sea conditions. The introduction of the flow guide hole 5 further optimizes the water flow distribution, effectively reducing the turbulence intensity in the water area behind the structure, and creating a good hydrodynamic environment for deep-sea fish farming or ecological protection.

[0037] In terms of ecological benefits, the present application creates a multi-level marine habitat. The stable vortex flow field formed in the moon pool 2 area provides an ideal gathering place for plankton, and the low-speed water flow area of the wave-encountering side concave arc surface becomes a good shelter for fish. The intermittent jet produced by the flow guide hole 5 simulates natural tidal movement, which is beneficial to maintaining water exchange and oxygen replenishment. The present application does not produce noise pollution or oil discharge during construction and operation, and coexists harmoniously with the surrounding marine ecosystem.

[0038] The double-arc surface built-in moon pool box-type floating breakwater structure described in the present application can achieve the best balance of economy, ecological friendliness and engineering efficiency through innovative design, and has broad application prospects and promotional value in the fields of coastal protection engineering and deep-sea fish farming. Its unique multi-stage energy dissipation mechanism and ecological compatible design provide a new technical solution for modern marine engineering.

Claims

1. A floating breakwater of the type with a double-arc built-in moon pool, characterized in that, The double-arc built-in moon pool box-type floating breakwater includes a floating box body (1), a moon pool (2), a wave-gathering plate (3), and a wave-guiding plate (4). The moon pool (2) is located in the middle of the main body of the pontoon (1) and runs vertically through the main body of the pontoon (1). The moon pool (2) divides the main body of the pontoon (1) into a symmetrically arranged front pontoon (10) and a rear pontoon (11). The front pontoon (10) is located on the wave-facing side of the main body of the pontoon (1), and the rear pontoon (11) is located on the wave-avoiding side of the main body of the pontoon (1). The front pontoon (10) has a vertically arranged shallow arched arc surface on its wave-facing surface, and wave-gathering plates (3) of the same size and shape are fixed on the arc surface; The back wave surface of the rear pontoon (11) is provided with a transversely arranged semi-cylindrical arc surface, and a wave guide plate (4) of the same size and shape is fixed on the arc surface. The main body (1) of the floating box between the wave-gathering plate (3) and the moon pool (2) is provided with multiple through, horizontally arranged guide holes (5). The water inlet of the guide hole (5) is located on the windward side of the front floating box (10), and the water outlet is located on the inner wall of the moon pool (2) near the wave-facing side. The wave-gathering plate (3) has a chord length of 1 / 10-1 / 15 of the incident wavelength L of the ocean wave and an arch height of 1 / 4 of the chord length; the moon pool (2) is a rectangular opening, symmetrically arranged in the center of the floating box body (1), the inner cavity length of the moon pool (2) is 1 / 15-1 / 20 of the incident wavelength L of the ocean wave and the width is 2 / 3 of the cavity length; the aperture of the guide holes (5) is 1 / 3-1 / 5 of the incident wave height H; the radius of the arc of the wave guide plate (4) is equal to the arch height of the wave-gathering plate (3).

2. The double-arc built-in moon pool box-type floating breakwater according to claim 1, characterized in that, The top and bottom surfaces of the front pontoon (10) corresponding to the shallow arched space where the wave-gathering plate (3) is located are respectively the first wing plate (6) and the second wing plate (7); with the opening direction of the wave-gathering plate (3) as the front, the two sides of the front pontoon (10) corresponding to the space in front of the wave-gathering plate (3) are respectively the first rib (8) and the second rib (9); the first wing plate (6) and the second wing plate (7) have the same thickness; the first rib (8) and the second rib (9) have the same thickness.

3. The double-arc built-in moon pool type floating breakwater according to claim 1, characterized in that, The top and bottom surfaces of the rear pontoon (11) corresponding to the semi-cylindrical space where the wave guide plate (4) is located are respectively the third wing plate (12) and the fourth wing plate (13); with the opening direction of the wave guide plate (4) as the front, the two sides of the rear pontoon (11) corresponding to the space in front of the wave guide plate (4) are respectively the third rib plate (14) and the fourth rib plate (15); the third wing plate (12) and the fourth wing plate (13) have the same thickness; the third rib plate (14) and the fourth rib plate (15) have the same thickness.

4. The double-arc built-in moon pool box-type floating breakwater according to claim 1, characterized in that, The main body of the pontoon (1), the wave-gathering plate (3) and the wave-guiding plate (4) are all made of composite polyethylene material as a whole.

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