A floating, through-type wave-damping and rectification device and wave-damping method

Abstract

This invention relates to the field of wave reduction and dissipation technology, and discloses a floating, through-type wave dissipation and rectification device and method. It includes a pontoon unit, with a limiting frame anchored to a breakwater or seabed above the pontoon unit. Each pontoon unit comprises at least two pontoons, the top of which is connected to the limiting frame via several connecting rings. Each pontoon has several parallel through-channels on its side. This invention effectively reduces wave energy in open sea areas through a unique dumbbell-shaped cavity structure and a flow-guiding slope design. The trapezoidal pontoons, combined with an elastic mooring system, form an adaptive mooring mechanism, maintaining the continuous and reliable operation of aquaculture facilities outside the bay under complex sea conditions.

Description

Technical Field

[0001] This invention relates to the field of wave reduction and wave elimination, and more specifically, to a buoyancy-based through-type wave elimination and rectification device and wave elimination method. Background Technology

[0002] When constructing a three-dimensional development pattern for marine aquaculture, it is necessary to conduct aquaculture pilot projects in the outer waters of the bay to explore aquaculture methods and technologies suitable for the marine environment.

[0003] Pilot aquaculture projects in the outer bay area need to overcome challenges such as the complex marine environment and great water depth, and improve the production efficiency and stability of aquaculture. Therefore, to solve problems such as wave impact faced by aquaculture in the outer bay area, wave reduction and mitigation facilities are needed to protect aquaculture facilities and organisms;

[0004] Because aquaculture facilities outside the bay are greatly affected by waves, currents and winds, resulting in heavy loads, a floating, through-type wave-dissipating and rectifying device is proposed to solve the above problems. Summary of the Invention

[0005] This invention provides a floating, through-type wave-dissipating and rectification device and method, which solves the technical problems of bay aquaculture facilities being greatly affected by waves, currents and winds, and the facilities bearing heavy loads in related technologies.

[0006] The present invention provides a floating through-type wave-damping and flow-rectifying device, including a pontoon unit. A limiting frame anchored to the embankment or seabed is provided above the pontoon unit. The pontoon unit includes at least two pontoons. The top of each pontoon is connected to the limiting frame through several connecting rings, and several parallel through-channels are provided on the side of each pontoon.

[0007] The through channel has a dumbbell-shaped expansion cavity in the middle. The expansion cavity includes a first cavity, a second cavity, and a connecting neck, with the connecting neck connecting the first cavity and the second cavity.

[0008] The through channel has an inlet channel on its front side, which is connected to the first cavity. The other end of the through channel has an outlet channel, which is connected to the second cavity. Both the inlet and outlet channels are funnel-shaped structures.

[0009] The inner walls of the first and second cavities of the expansion cavity are equipped with turbulence generators, which include several staggered hexagonal protrusions.

[0010] A cavitation enhancement section is provided on the inner wall of the connecting neck. The cavitation enhancement section includes a guide spring and a micro-protrusion array. The micro-protrusion array is distributed on the inner wall of the guide spring and is composed of several ceramic hemispheres.

[0011] A flow guide slope is provided between the first cavity and the inlet channel, and between the second cavity and the outlet channel. The flow guide slope is a 45° conical slope.

[0012] Furthermore, the guide spring is hourglass-shaped, with its central tube wall recessed to form an elastic adjustment area, and its two ends fixedly connected to the inner wall of the connecting neck, with a deformation gap left between the elastic adjustment area and the inner wall of the connecting neck.

[0013] Furthermore, a 20° chamfer is provided at the top edge of the hexagonal protrusion, and the chamfered surface forms a boundary layer separation zone. An arc-shaped transition zone is provided between the bottom of the six sides of the hexagonal protrusion and the inner wall of the expansion cavity. The arc-shaped transition zone forms a cavitation zone at the edge of the protrusion, and the flow channel between adjacent hexagonal protrusion sidewalls forms a vortex stretching zone.

[0014] Furthermore, all the pontoons are truncated quadrangular in shape, with a side inclination angle of 12°-15°, a ratio between the side length of the top surface and the side length of the bottom surface of the pontoon of 1:1.2-1.5, and a height to bottom surface ratio of 0.6-0.8; and the contact surfaces between adjacent pontoons are provided with anti-collision fenders.

[0015] Furthermore, detection ends are provided on the inner walls of the inlet channel, outlet channel, first cavity, second cavity, and connecting neck, and the detection ends are connected to a flow rate sensor for detecting the internal water flow velocity.

[0016] Furthermore, each pontoon has a sand-flushing hole at its bottom, which is connected to a through channel.

[0017] Furthermore, the ratio between the diameter of the inlet / outlet channel and the inner diameter of the expansion chamber is between 1:3.5 and 1:3.6.

[0018] Furthermore, the bottom of the pontoon is equipped with a universal swivel ring, which is connected to the seabed anchor pile via an elastic anchor chain.

[0019] Furthermore, the pontoon is made of lightweight waterproof material, with a polyurea waterproof coating on its surface and a polytetrafluoroethylene coating added to the lower half of the pontoon.

[0020] This invention also proposes a floating, through-type wave-damping method, which uses the aforementioned floating, through-type wave-damping and rectification device to dampen waves, including the following steps:

[0021] Step 1, Water Filling Stage: Waves surge towards the entrance of the through channel. Water flows through the entrance channel and enters the expansion chamber after accelerating on the guide slope. Due to the sudden expansion of the expansion chamber, the wave velocity drops from the initial velocity at the entrance to 0.3 times the initial velocity. Part of the expansion chamber volume is filled by low-velocity water to form a rotating "water cushion".

[0022] Step 2, Impact Stage: The new wave crest enters with an initial velocity and is also guided by the guide slope to impact the "water cushion". The two water flows combine and collide, resulting in energy conversion. The energy conversion includes: axial kinetic energy loss, velocity gradient generating turbulent kinetic energy, and the formation of Taylor-Green vortex rings.

[0023] Step 3, dissipation stage: The residual water flow impacts the hexagonal protrusions inside the expansion cavity, where a Karman vortex street is formed in the boundary layer separation zone of the hexagonal protrusions, local cavitation is induced in the cavitation zone at the edge of the hexagonal protrusions, and energy level chaining is triggered in the vortex stretching zone between the hexagonal protrusions. At the same time, the water flow is decelerated and diffused through the guide slope of the outlet channel, and kinetic energy is converted into thermal energy.

[0024] Step 4, Drainage Stage: During the trough period, the water in the expansion chamber is discharged through the outlet channel, and the bottom sand flushing hole is manually started to remove silt when the flow velocity is <0.2m / s.

[0025] The beneficial effects of this invention are as follows:

[0026] This invention effectively reduces wave energy in open sea areas through a unique dumbbell-shaped cavity structure and a flow-guiding slope design. The trapezoidal buoy, combined with an elastic mooring system, forms an adaptive mooring mechanism, maintaining the spatial stability of the facility under complex sea conditions, ensuring the safety of aquaculture cages, and enabling aquaculture facilities outside the bay to have continuous and reliable operation capabilities in harsh marine environments, thus providing an inherent safety barrier for the deep-sea aquaculture industry. Attached Figure Description

[0027] Figure 1 This is a structural schematic diagram of a floating through-type wave-damping and rectification device according to the present invention;

[0028] Figure 2 This is a front view of a floating, through-type wave-damping and rectification device according to the present invention;

[0029] Figure 3 This is the invention Figure 2 Schematic diagram of the cross-sectional structure of A1A2 (A1A2 is a horizontal cross-section);

[0030] Figure 4 This is the invention Figure 3 Enlarged view of the local B structure in the middle;

[0031] Figure 5 This is a schematic diagram of the partition structure of the hexagonal protrusions of the present invention;

[0032] Figure 6 This is a partial structural schematic diagram of the turbulence generator of a floating, through-type wave-damping and rectification device proposed in this invention;

[0033] Figure 7 This is a schematic diagram illustrating the wave-suppression effect of the wave-suppression and rectification device of the present invention.

[0034] In the diagram: 100, First pontoon; 110, Inlet channel; 120, Outlet channel; 130, First cavity; 140, Connecting neck; 150, Hexagonal protrusion; 151, Boundary layer separation zone; 152, Cavitation zone at the edge of the protrusion; 153, Vortex stretching zone; 160, Guide slope; 170, Second cavity; 180, Cavitation enhancement section; 181, Guide spring; 182, Micro-protrusion array; 200, Second pontoon; 300, Connecting ring; 400, Limiting frame; 500, Anti-collision fender; 600, Universal swivel ring; 700, Flow sensor. Detailed Implementation

[0035] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0036] like Figures 1-7 As shown, a floating, through-type wave-damping and rectification device includes:

[0037] A floating box unit comprises at least two floating boxes, such as Figure 1 As shown, both the first pontoon 100 and the second pontoon 200 are made of lightweight waterproof materials (such as closed-cell foam) to ensure anti-sinking properties, and their surfaces are covered with a polyurea waterproof coating.

[0038] The top sides of the first pontoon 100 and the second pontoon 200 are connected to the limiting frame 400 through connecting rings 300. The limiting frame 400 is a frame structure welded from circular steel pipes. Its structure is roof-shaped. The limiting frame 400 can be fixed to the edge of the embankment, seabed or other waters that need wave dissipation by gravity anchor. It is clearance-fitted with the connecting ring 300 of the pontoon unit to limit the large range of horizontal displacement of the pontoon unit, but allows vertical swaying motion perpendicular to the sea level.

[0039] The first pontoon 100 and the second pontoon 200 have several parallel through channels on their sides, such as... Figure 1 As shown, seven parallel through channels are provided on the end face of its frontal surface, and they are divided into two layers. The through channels of the two layers are staggered in the vertical direction.

[0040] The bottom of the first pontoon 100 and the second pontoon 200 is equipped with a universal swivel ring 600. The universal swivel ring 600 is connected to the seabed anchor pile through an elastic anchor chain. The swing angle of the universal swivel ring 600 is ±30°. At the same time, the surface of the rotating shaft of the universal swivel ring 600 is coated with a ceramic layer. A tension sensor is installed at the end of the elastic anchor chain to monitor the load in real time. Each pontoon unit is equipped with at least 2-3 anchor chains to distribute the load. The elastic anchor chain is a rubber core steel wire rope composite structure. Each pontoon unit is equipped with at least 3 anchor chains, which are evenly distributed at 120° and the angle between them and the seabed is between 30° and 45°.

[0041] The first pontoon 100 and the second pontoon 200 are both truncated quadrangular, with a side inclination angle of 12°-15°, a ratio of the side length of the top surface to the side length of the bottom surface of 1:1.2-1.5, and a ratio of the height to the side length of the bottom surface of 0.6-0.8.

[0042] A collision protection fender 500 is provided between the contact surfaces of the first pontoon 100 and the second pontoon 200. The collision protection fender 500 is used to buffer collision energy.

[0043] The through channel has a dumbbell-shaped expansion cavity in the middle. The expansion cavity includes a first cavity 130, a second cavity 170 and a connecting neck 140, which connects the first cavity 130 and the second cavity 170.

[0044] The through channel has an inlet channel 110 on its front side, which is connected to the first cavity 130. The other end of the through channel has an outlet channel 120, which is connected to the second cavity 170. Both the inlet channel 110 and the outlet channel 120 are funnel-shaped structures.

[0045] The inner walls of the first cavity 130 and the second cavity 170 of the expansion cavity are equipped with turbulence generators, which include several staggered hexagonal protrusions 150.

[0046] like Figure 5 and Figure 6 As shown, in one embodiment of the present invention, the hexagonal protrusion 150 is mainly divided into three parts:

[0047] 1. Boundary layer separation region 151

[0048] Location: The beveled area formed by a 20° chamfer at the top edge corner;

[0049] When the residual water flows over the protrusion: the water flow accelerates on the front side of the protrusion (the pressure drops to the lowest point), and the water flow separates when it accelerates to the rear edge of the top, forming a periodically detached vortex.

[0050] Energy conversion: vortex shedding leads to the conversion of fluid kinetic energy into vortex kinetic energy;

[0051] 2. Cavitation zone at the raised edge 152

[0052] Location: Curvature transition zone at the root of the protrusion (an arc-shaped transition zone is provided between the bottom of the six sides of the hexagonal protrusion and the inner wall of the expansion cavity);

[0053] Cavitation triggering conditions: local flow velocity ≥ 3.2 m / s, pressure drops to the saturated vapor pressure of water;

[0054] 3. Scroll stretching zone 153

[0055] Location: The flow channel between the sidewalls of adjacent protrusions;

[0056] Energy transfer path: Large-scale vortices (centimeter scale) are sheared by convex edges and decomposed into mesoscale vortices (millimeter scale), which are then dissipated into heat energy through viscosity;

[0057] A cavitation enhancement section 180 is provided on the inner sidewall of the connecting neck 140. The cavitation enhancement section 180 includes a guide spring 181 and a micro protrusion array 182. The micro protrusion array 182 is distributed on the inner sidewall of the guide spring 181 and is composed of a number of ceramic hemispheres.

[0058] The guide spring 181 is hourglass-shaped, with its central tube wall recessed to form an elastic adjustment area. Its two ends are fixedly connected to the inner wall of the connecting neck 140, and a deformation gap is left between the elastic adjustment area and the inner wall of the connecting neck 140.

[0059] The guide spring 181 can pre-deflect the water flow. When the guide spring 181 is impacted by the water flow on one side, it reduces the entry impact angle between two adjacent cavities through its own deformation, thereby reducing the turbulence of the "water cushion". The micro protrusion array 182 increases the surface roughness of the connecting neck 140, thereby suppressing the initial generation of cavitation bubbles.

[0060] A flow guiding slope 160 is provided between the first cavity 130 and the inlet channel 110, and between the second cavity 170 and the outlet channel 120. That is, the flow guiding slope 160 is located at the opposite ends of the first cavity 130 and the second cavity 170. The flow guiding slope 160 is a 45° conical slope, and the surface of the conical slope is polished to reduce friction loss.

[0061] Detection ends are provided on the inner walls of the inlet channel 110, outlet channel 120, first cavity 130, second cavity 170 and connecting neck 140, and the detection ends are connected to a flow rate sensor 700 for detecting the internal water flow velocity.

[0062] Both the first float 100 and the second float 200 have sand flushing holes at their bottoms. The sand flushing holes are connected to the bottom end of the cavity of the through channel, and the sand flushing holes are equipped with plugs that can be opened manually.

[0063] It should be noted that the ratio of the diameter of the inlet channel 110 / outlet channel 120 to the inner diameter of the expansion chamber is 1:3.5-1:3.6 to ensure a sudden drop in flow velocity (V0→0.3V0).

[0064] It should also be noted that the guide spring 181 is a cylindrical structure formed by a titanium alloy arc-shaped thin sheet. At least two sets of fixing inserts are provided at the outer edges of both ends of the cylindrical structure. The guide spring 181 is stably installed at the connecting neck 140 through the fixing inserts. The micro protrusions are silicon nitride ceramic hemispheres arranged in a rhomboid array.

[0065] The float unit can be assembled by multi-layer bonding. Its splicing surface passes through the central axis of the through channel at the same horizontal height, that is, the through channel is divided into two half chambers to facilitate the installation of the guide spring 181. The inner wall of the connecting neck 140 can be provided with annular grooves that cooperate with the fixing inserts at both ends of the guide spring 181. After the guide spring 181 is installed into the corresponding annular groove, the guide spring 181 can be fixed in the annular groove with structural adhesive for further fixation.

[0066] It should also be noted that the addition of a polytetrafluoroethylene coating to the lower half of the float unit reduces the adhesion strength of the barnacles.

[0067] This invention also proposes a buoyancy-through wave-damping and rectification method, comprising the following steps:

[0068] Step 1, Water Filling Stage (T1 Cycle):

[0069] Waves surge toward the entrance of the through channel. Water flows through the entrance channel (110) into the guide slope (160). After being accelerated by the guide slope (160), it enters the expansion chamber. As the expansion chamber suddenly expands, the flow velocity drops from V0 at the entrance to 0.3V0. Part of the expansion chamber volume is filled with low-velocity water, forming a rotating "water cushion". The guide slope 160 guides the water flow to rotate along the chamber wall, forming a preliminary vortex.

[0070] Where V0 is the initial velocity entering the entrance channel 110;

[0071] Step 2, Impact Phase (T2 Cycle):

[0072] As the next peak arrives, a new water flow passes through the inlet channel (110) at a speed of V0. Guided by the guide slope 160, the new water flow directly impacts the stagnant "water cushion" inside the cavity, resulting in a near-horizontal collision between the two water flows. After being accelerated by the rotation of the guide slope 160, the high-speed water flow impacts the rotating "water cushion," generating three energy conversions:

[0073] a) Momentum cancellation: Axial kinetic energy loss;

[0074] b) Shear dissipation: Velocity gradients induce turbulent kinetic energy generation;

[0075] c) Vortex evolution: The collision zone forms a Taylor-Green vortex ring;

[0076] Step 3, Dissipation stage (T2+Δt, where Δt is the time difference between the current impact stage and the next water filling stage):

[0077] The residual water flow impacts the hexagonal protrusion 150, resulting in the following physical processes:

[0078] Specifically, a Karman vortex street is formed in the boundary layer separation region of the hexagonal protrusion 150, and local cavitation occurs in the cavitation region at the protrusion edge of the hexagonal protrusion 150 (for example, when the cavitation number σ=0.8, the corresponding flow velocity is 2.5m / s-3.0m / s). The vortex stretching region between the hexagonal protrusions 150 leads to energy level chaining (energy transfer to a smaller scale). The water flow is decelerated and diffused through the outlet guide slope 160, and the kinetic energy is further converted into thermal energy.

[0079] Step 4, Emptying Phase (T3 Cycle):

[0080] During the trough period, the water inside the expansion chamber is slowly discharged through the outlet channel 120. The double-flange design of the outlet channel 120 prevents excessive suction from causing structural cavitation. The sediment is removed by gravity by manually opening the bottom flushing hole.

[0081] Verification of wave-suppressing and rectifier equipment:

[0082] The wave-damping and rectification equipment was placed in the pilot aquaculture area outside the bay in the actual sea area to ensure that it was in a typical marine environment to simulate real aquaculture conditions.

[0083] Three wave height meters were installed to monitor wave heights at different locations.

[0084] Wave height meter 1: Placed 1 meter in front of the wave-suppressing and rectifying equipment, it is used to measure the original wave height before the equipment processing.

[0085] Wave height meter 2: Placed 2.79 meters behind the back flow surface of the wave-dissipating and rectifying equipment, it is used to measure the wave-dissipating effect at the far end of the equipment.

[0086] Wave height meter 3: Placed 0.98 meters behind the back flow surface of the wave-dissipating and rectifying equipment, it is used to measure the wave-dissipating effect near the equipment.

[0087] A comparison of wave height meter data shows (see...) Figure 7 The wave heights at both the near end (wave height meter 3) and the far end (wave height meter 2) of the equipment were significantly lower than those at the front end (wave height meter 1). The wave-dissipating and rectifying equipment can effectively reduce the wave height at the back end and significantly reduce the impact of waves on aquaculture facilities, indicating that the equipment has good wave-dissipating and rectifying capabilities.

[0088] To further verify the wave suppression and rectification equipment's wave suppression effect on different wave heights, this invention tested the equipment's wave suppression effect on different wave heights.

[0089] The experimental results were analyzed using the transmission coefficient to assess the wave-damping effect of the wave-damping and rectifier equipment. H t and H i These represent the transmitted wave height and the incident wave height, respectively; the ratio of the two is the transmission coefficient. A smaller transmission coefficient indicates a stronger wave-damping capability and a better wave-damping effect from the wave-damping and rectifying equipment. The experimental data are shown in the table below:

[0090]

[0091]

[0092] As can be seen from the table, the equipment has a certain wave reduction effect at different wave heights, and the effect is more significant under medium and higher wave height conditions.

[0093] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention, all of which are within the protection scope of the present invention.

Claims

1. A buoyant, through-type wave-damping and rectification device, characterized in that, The system includes a pontoon unit, with a limiting frame (400) fixed to the embankment or seabed by gravity anchors on the top of the pontoon unit. The pontoon unit includes at least two pontoons, with the top of each pontoon connected to the limiting frame (400) by several connecting rings (300), and each pontoon has several parallel through channels on its side. The through channel has a dumbbell-shaped expansion cavity in the middle. The expansion cavity includes a first cavity (130), a second cavity (170), and a connecting neck (140). The connecting neck (140) connects the first cavity (130) and the second cavity (170). The inlet channel (110) is provided on the flow-facing side of the through channel. The inlet channel (110) is connected to the first cavity (130). The outlet channel (120) is provided at the other end of the through channel. The outlet channel (120) is connected to the second cavity (170). Both the inlet channel (110) and the outlet channel (120) are funnel-shaped structures. The inner walls of the first cavity (130) and the second cavity (170) of the expansion cavity are equipped with turbulence generators, which include several staggered hexagonal protrusions (150). A cavitation enhancement section (180) is provided on the inner wall of the connecting neck (140). The cavitation enhancement section (180) includes a guide spring (181) and a micro protrusion array (182). The micro protrusion array (182) is distributed on the inner wall of the guide spring (181) and is composed of a number of ceramic hemispheres. A flow guide slope (160) is provided between the first cavity (130) and the inlet channel (110) and between the second cavity (170) and the outlet channel (120). The flow guide slope (160) is a 45° conical slope.

2. The buoyancy-guided, through-type wave-damping and rectification device according to claim 1, characterized in that, The guide spring (181) is hourglass-shaped, with its central tube wall recessed to form an elastic adjustment area. Its two ends are fixedly connected to the inner wall of the connecting neck (140), and a deformation gap is left between the elastic adjustment area and the inner wall of the connecting neck (140).

3. The buoyancy-guided, through-type wave-damping and rectification device according to claim 2, characterized in that, The top edge of the hexagonal protrusion (150) is chamfered at 20°, and the chamfered surface forms a boundary layer separation zone (151). There is an arc-shaped transition zone between the bottom of the six sides of the hexagonal protrusion (150) and the inner wall of the expansion cavity. The arc-shaped transition zone forms a cavitation zone (152) at the edge of the protrusion. The flow channel between the side walls of adjacent hexagonal protrusions (150) forms a vortex stretching zone (153).

4. The buoyancy-guided, through-type wave-damping and rectification device according to claim 3, characterized in that, The pontoons are all truncated quadrangular in shape, with a side inclination angle of 12°-15°, a ratio between the top side length and the bottom side length of the pontoon of 1:1.2-1.5, and a height to bottom side length ratio of 0.6-0.

8. Furthermore, the contact surfaces between adjacent pontoons are equipped with anti-collision fenders (500).

5. A buoyant, through-type wave-damping and rectification device according to claim 4, characterized in that, Detection ends are provided on the inner walls of the inlet channel (110), outlet channel (120), first cavity (130), second cavity (170) and connecting neck (140), and the detection ends are connected to a flow velocity sensor (700) for detecting the internal water flow velocity.

6. A buoyant, through-type wave-damping and rectification device according to claim 5, characterized in that, Each pontoon has a sand-flushing hole at the bottom, which is connected to a through channel.

7. A buoyant, through-type wave-damping and rectification device according to claim 5, characterized in that, The ratio between the diameter of the inlet channel (110) / outlet channel (120) and the inner diameter of the expansion chamber is between 1:3.5 and 1:3.

6.

8. A buoyant, through-type wave-damping and rectification device according to claim 3, characterized in that, The bottom of the pontoon is equipped with a universal swivel ring (600), which is connected to the seabed anchor pile by an elastic anchor chain.

9. A buoyant, through-type wave-damping and rectification device according to claim 7, characterized in that, The pontoon is made of lightweight waterproof material, with a polyurea waterproof coating on the surface and a polytetrafluoroethylene coating on the lower half of the pontoon.

10. A buoyancy-based, continuous wave-damping method, characterized in that, Wave suppression using a buoyant, through-type wave-damping and rectification device as described in any one of claims 3-9 includes the following steps: Step 1, Water filling stage: Waves surge towards the entrance of the through channel. Water flows through the entrance channel (110) into the guide slope (160) and accelerates before entering the expansion cavity. Due to the sudden expansion of the expansion cavity, the wave velocity drops from the initial velocity at the entrance to 0.3 times the initial velocity. Part of the expansion cavity volume is filled by low-velocity water to form a rotating "water cushion". Step 2, Impact Stage: The new wave crest enters with an initial velocity and is also guided by the guide slope (160) to impact the "water cushion". The two water flows combine and collide, generating energy conversion. The energy conversion includes: axial kinetic energy loss, velocity gradient generating turbulent kinetic energy and forming Taylor-Green vortex rings. Step 3, dissipation stage: The residual water flow impacts the hexagonal protrusions (150) inside the expansion cavity, where a Karman vortex street is formed in the boundary layer separation zone (151) of the hexagonal protrusions (150), the cavitation zone (152) at the protrusion edge of the hexagonal protrusions (150) induces local cavitation, and the vortex stretching zone (153) between the hexagonal protrusions (150) triggers energy level chaining. At the same time, the water flow is decelerated and diffused through the guide slope (160) of the outlet channel (120), and the kinetic energy is converted into thermal energy. Step 4, Emptying stage: During the trough period, the water in the expansion chamber is discharged through the outlet channel (120), and the bottom sand flushing hole is manually started to clean up the silt when the flow velocity is <0.2m / s.

Images