A double parabolic breakwater structure

Abstract

The application provides a double-parabolic breakwater structure, and relates to the technical fields of coastal engineering and wave energy utilization, and comprises a main wall and a secondary wall, wherein the secondary wall is arranged in the inner water area of the main wall, the main wall and the secondary wall are in parabolic arc shape in the cross section, the main wall is a fixed reflection wall body penetrating through the water surface, the secondary wall is a submerged reflection wall body, and there is a confocal or quasi-confocal relationship between the parabolas of the main wall and the secondary wall; the focal point wave height of the main wall is regulated by regulating the secondary wall. Through the above scheme, selective enhancement and flexible regulation of different wave period wave energy are realized, and efficient integration with a wave energy conversion device is facilitated.

Description

Technical Field

[0001] This invention relates to the field of coastal engineering and wave energy utilization technology, and more specifically, to a double parabolic breakwater structure. Background Technology

[0002] In the field of coastal engineering and wave energy utilization, the traditional function of breakwaters is mainly to resist the impact of open sea waves on harbor basins, shorelines, and coastal facilities, ensuring channel stability and operational safety. These breakwaters typically employ vertical, sloping, or hybrid structures to weaken wave energy through wave attenuation, reflection, or transmission. However, with the development of wave energy converters (WECs), especially nearshore or offshore devices such as oscillating water column (OWC) and float-type (point absorption) devices, which have higher requirements for incident wave energy density, simple wave attenuation is no longer sufficient to meet the demand for efficient energy capture. Existing wave-focusing or wave-damping devices mostly employ fixed geometries (such as straight, circular, or parabolic reflectors) to reflect and focus waves. While these fixed structures can generate a certain wave energy enhancement under designed wave conditions, they generally lack the ability to adapt to changes in the incident wave period, direction, and wave spectrum. They cannot flexibly adjust the wave height and phase response at the focal point under unsteady wave conditions in actual sea areas. Therefore, a wave-focusing structure with multi-degree-of-freedom tuning capabilities is needed. Summary of the Invention

[0003] In view of this, the present invention proposes a double parabolic breakwater structure to solve the problems existing in the prior art.

[0004] To achieve the above objectives, this invention proposes a double parabolic breakwater structure, comprising: The system comprises a main wall and a secondary wall, wherein the secondary wall is located within the water area inside the main wall. The main wall and the secondary wall are parabolic arc shapes in cross-section. The main wall is a fixed reflective wall that penetrates the water surface, and the secondary wall is a submerged reflective wall. The parabolic curves of the main wall and the secondary wall are confocal or quasi-confocal. The focal wave height of the main wall is controlled by adjusting the secondary wall.

[0005] Optionally, the position, chord length, and flooding depth of the secondary wall can be adjusted.

[0006] Optionally, the position of the secondary wall can be adjusted by a position adjustment mechanism, which is used to move the secondary wall horizontally and adjust the distance between the focal points corresponding to the main wall and the secondary wall.

[0007] Optionally, the submersion depth of the secondary wall can be controlled by a submersion depth adjustment mechanism, which may be a lifting support frame, a buoyancy chamber combined with a mooring depth adjustment structure, or a telescopic support structure.

[0008] Optionally, the secondary wall is a modular secondary wall, which is composed of several line segment modules spliced ​​together, and the line segment modules are connected by a detachable connection structure.

[0009] Optionally, a device base is provided in the focal region of the parabola between the main wall and the secondary wall, and the device base is used to install the wave energy conversion device.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: supply , , Three independent tuning degrees of freedom allow for controlled enhancement or suppression of the focal wave height without altering the main wall geometry; Selective enhancement of different wave periods is achieved through phase control, which facilitates matching with the dominant wave conditions of the target sea area; The modular and adjustable installation of the secondary wall facilitates engineering implementation, maintenance, and integration with wave energy conversion devices (such as OWC, floats, etc.) to increase incident wave energy density. With a clear structural mechanism, the main wall provides a geometric focusing baseline, while the secondary wall provides delayed scattering echoes and utilizes phase interference for control. It is suitable for the design and optimization of wave focusing and energy utilization systems in coastal engineering. Attached Figure Description

[0011] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. In the drawings: Figure 1 This is a top view of the main wall and secondary wall in an embodiment of the present invention; Figure 2 This is a structural diagram of the main wall and secondary wall as configured in an embodiment of the present invention; Figure 3 This is a comparison diagram of wave energy of only the main wall structure in the embodiments of the present invention; Figure 4 This is a comparison diagram of the wave energy of the proposed double-wall structure in the embodiments of the present invention; Figure 5 This is a wave height diagram corresponding to the horizontal spacing of the focal points of different main walls and secondary walls in an embodiment of the present invention. Detailed Implementation

[0012] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0013] This embodiment proposes a double parabolic breakwater structure, particularly a double parabolic breakwater structure and its tuning method for nearshore wave focusing and energy enhancement. It can be integrated with wave energy conversion devices (WECs, such as OWCs, floats, etc.). Figure 1 and Figure 2 As shown, it includes: The primary parabolic reflector and the secondary parabolic reflector; wherein: The main parabolic reflector serves as the main wall, a fixed parabolic reflective wall that penetrates the water surface. It forms a parabolic arc in plan and has a first focal point. chord length With focal length Gravity-based, pile-based, or anchored foundations can be used for the fixed installation of the main wall.

[0014] Its function is to utilize the geometric reflection properties of a parabola to form a baseline focusing field near the focal point of the incident gravity wave.

[0015] The secondary parabolic reflector, serving as a secondary wall, is located within the water area inside the main wall. It is a submerged parabolic reflector, also exhibiting a parabolic arc in plan view, and possesses a second focal point. chord length With focal length The submersion depth of the secondary wall is defined as... , This is the distance from the top of the secondary wall to the still water surface. Adjustable. The secondary wall can be designed to be cofocal or quasi-cofocal with the main wall. Cofocal or quasi-cofocal means: and Can be with Coincident or offset (between -2m and +2m).

[0016] The secondary wall does not simply increase the reflective area, but rather acts as a secondary scattering boundary, generating a reflected wave component that returns to the focal region. Because there is a propagation path between the secondary wall and the focal point, this scattering component has a certain propagation delay when it reaches the focal region, thus resulting in phase superposition with the baseline focusing field of the primary wall.

[0017] The horizontal distance between the two foci of the primary parabolic reflector and the secondary parabolic reflector is:

[0018] in This indicates that the secondary wall focus is located downstream of the primary wall focus (to the right of the incident propagation direction). Indicates upstream. , This indicates the horizontal position of the secondary wall focal point and the primary wall focal point.

[0019] To achieve adjustable focusing effect, this invention provides a variety of adjustment mechanisms: Among them, the adjustment mechanism can be used to adjust , and This achieves a coordinated focusing effect. The adjustment structure includes the following: The position adjustment mechanism is used to change the horizontal distance between the two focal points. The secondary wall is installed on the foundation platform via guide rails / sliding bases / inter-pile grooves, and moves horizontally in conjunction with a winch, hydraulic cylinder, or screw mechanism; positioning holes / limit blocks can be set for quick locking of different positions. .

[0020] The flooding depth adjustment mechanism is used to change the flooding depth of the secondary wall. The secondary wall adopts a liftable support frame, buoyancy chamber + mooring depth adjustment, or telescopic support structure to change the burial depth of the top of the secondary wall relative to the still water surface.

[0021] Modular secondary walls are used to change the chord length of the adjustable secondary walls. The secondary wall is spliced ​​together from multiple parabolic segment modules, and the chord length can be extended or shortened by using detachable connections (bolts / pins / locks).

[0022] Alternatively, a device base may be provided in the focal area for arranging OWC, floats, or other WECs.

[0023] like Figure 3-4 As shown, the double-wall structure with a main wall and a secondary wall in this invention provides greater wave energy at the focal point compared to a single-wall structure with only a main wall, thus providing greater energy for wave energy conversion devices such as OWC.

[0024] Working principle: The principal wall's geometric focusing provides the baseline focusing field: the principal parabolic reflector utilizes the parabolic geometric reflection properties to create a locally amplified region of reflected energy of the incident gravity wave near its focal point, thereby... A baseline-focused wavefield (single-reflector focusing) is generated nearby. This focusing effect is frequency-selective, and the peak amplification is usually determined by both geometric parameters and wave dispersion.

[0025] The secondary wall acts as an adjustable scattering source, introducing delayed echoes and achieving phase tuning: the secondary parabolic reflector is a submerged structure, and its function is not simply to increase the reflecting area, but to act as a secondary scattering boundary to generate the reflected wave component returning to the focal region, i.e., the delayed echo. Since there is a propagation path between the secondary wall and the focal point, the scattered component has a propagation delay (group delay) to reach the focal region, thus superimposing with the focusing field of the primary wall near the focal point.

[0026] The primary wall provides the baseline focusing field, while the secondary wall acts as an adjustable scattering source to introduce delayed echoes. The composite wave height at the focal point... Approximately, near the focal point, the primary focusing component and the return component induced by the secondary wall can be phase-superimposed:

[0027] in The baseline component generated by the main wall focusing This refers to the secondary wall-scattered echo component; Let i be the phase difference between the two at the focal point, where i represents the power and e represents a natural number.

[0028] By adjusting Change phase difference Constructive interference can be achieved. near (significantly enhanced wave height) or destructive interference ( near (Wave height decreases).

[0029] adjust This affects the amplitude and equivalent phase of the scattered field. Due to the local wave-wall interaction under finite size and flooding conditions, the focus gain increases with... It exhibits a non-monotonic variation and has an optimal range of chord lengths.

[0030] Adjusting flood depth This can simultaneously change the fluid motion intensity and phase response near the secondary wall: with shallow submersion, higher-order harmonics are enhanced and the coherence of the dominant frequency is weakened; with deeper submersion, the scattering components are generally weakened but the spectral composition is purer, thus there exists an optimal intermediate submersion depth.

[0031] Among them, the above-mentioned different parameters can be continuously adjusted according to the observed waves through relevant simulation methods or in field measurements, with the goal of maximizing the waves, to determine the parameters corresponding to the optimal or preset wave energy for practical use.

[0032] Specifically: through By modulating the propagation phase, constructive or destructive interference can be achieved, resulting in frequency selectivity: Change the position of the secondary wall. This will change the propagation path length of the echo and the time delay before it reaches the focal point, thus changing... (Including propagation phase and group delay effects). When near ( When the integer value is used, structural interference occurs, and the wave height at the focal point is significantly enhanced; when the integer value is used, structural interference occurs. near At this time, destructive interference occurs, and the focal wave height decreases or even falls below the baseline. Among these, the optimal D value corresponding to different frequencies can be found. f (That is, the D of structural interference) f This allows for the adjustment of D at different frequencies. f This maximizes the energy at the focal point F1.

[0033] Therefore, the system exhibits a typical "peak-valley-peak" pattern. The oscillation changes and the "optimal branch switching" occur with the change of wave period, forming an adjustable strong frequency selective focusing.

[0034] like Figure 5 As shown, regarding the above-mentioned D f After adding the secondary wall structure, there is a sinusoidal relationship between it and the maximum wave energy. Therefore, the relationship can be adjusted by controlling the aforementioned focal spacing D. f This can enhance wave energy at the focal point. Guided by the above principle, this distance can be used to measure wave energy magnitude during secondary wall parameter adjustment, record the location of the secondary wall with the highest observed wave energy, and select the optimal focal parameter between the secondary wall and the primary wall.

[0035] Specifically: chord length Factors affecting the amplitude and equivalent phase of the scattered field: Increasing the chord length of the secondary wall usually increases its effective range for the incident wave and enhances the amplitude of the scattered component. However, due to the finite size of the secondary wall and the local wave-wall interaction under flooding conditions, the scattered field has different phases at different locations along the wall. Increasing the chord length introduces contributions from the outer segments, which may experience phase deflection, partially canceling out the scattering contributions from the central segments. Therefore, the focus gain increases with... It is non-monotonic and has an optimal range of chord lengths.

[0036] These phase effects caused by finite string length, flooding, and local multiple scattering can be grouped into an equivalent phase shift term for qualitative interpretation. The resulting phase cross-quadrant and gain changes.

[0037] Based on the above principle, similarly, as a guide, the chord length can be determined by measuring the wave energy during the adjustment of secondary wall parameters, recording the secondary wall chord length parameter with the largest observed wave energy, and thus determining the optimal selection of the secondary wall chord length parameter.

[0038] Specifically: flood depth Simultaneous modulation of "phase coherence" and "spectral composition": The depth of flooding alters the intensity and phase response characteristics of fluid motion near the secondary wall: Shallow flooding (flooding depth) (If the value is less than the preset threshold), the interaction between the near-free surfaces near the top of the secondary wall is enhanced, which can easily introduce stronger phase shift and induce more obvious higher-order harmonic components (the spectral energy is redistributed to higher-order components), making the coherent superposition of the main frequency components at the focal point weaker. When submerged at deeper depths (submersion depth) (Greater than or equal to the preset threshold), the incident fluctuation attenuates with depth, the scattering component weakens overall, but the spectrum is more concentrated at the main frequency, and the focal response is "cleaner"; Therefore, the maximum wave energy right It also exhibits a non-monotonic pattern with an optimal intermediate flooding depth.

[0039] Based on the above principles, similarly, as a guide, the inundation depth can be determined by measuring the wave energy during the adjustment of secondary wall parameters, recording the inundation depth with the maximum observed wave energy, and thus determining the optimal selection of the secondary wall inundation depth.

[0040] Compared with existing single parabolic wave-collecting structures, the present invention has at least the following advantages: 1. Provides additional tuning freedom ( This allows for the controllable enhancement or suppression of the focal wave height without altering the geometry of the main wall; 2. Selective enhancement of different wave periods is achieved through phase control, which facilitates matching with the dominant wave conditions in the target sea area; 3. The modular and adjustable installation of the secondary wall facilitates engineering implementation and maintenance, and can be integrated with WEC to improve the incident wave energy density of the device; 4. Clear structural mechanism: The main wall provides the geometric focusing baseline, and the secondary wall provides delayed scattering echoes and achieves control through phase interference, which is suitable for design and optimization.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A double parabolic breakwater structure, characterized in that, include: The system comprises a main wall and a secondary wall, wherein the secondary wall is located within the water area inside the main wall. The main wall and the secondary wall are parabolic in cross-section. The main wall is a fixed reflective wall that penetrates the water surface, and the secondary wall is a submerged reflective wall. The parabolic curves of the main wall and the secondary wall are confocal or quasi-confocal. The wave height at the focal point can be controlled by adjusting the secondary wall.

2. The structure according to claim 1, characterized in that, The position, chord length, and flooding depth of the secondary wall are adjusted.

3. The structure according to claim 2, characterized in that, The position of the secondary wall is adjusted by a position adjustment mechanism, which is used to move the secondary wall horizontally and adjust the distance between the focal points corresponding to the main wall and the secondary wall.

4. The structure according to claim 1, characterized in that, The submersion depth of the secondary wall is controlled by a submersion depth adjustment mechanism, which adopts a lifting support frame, a buoyancy chamber combined with a mooring depth adjustment structure or a telescopic support structure.

5. The structure according to claim 1, characterized in that, The secondary wall is a modular secondary wall, which is composed of several line segment modules spliced ​​together and connected by a detachable connection structure.

6. The structure according to claim 1, characterized in that, A device base is provided in the focal region of the parabola between the main wall and the secondary wall, and the device base is used to install the wave energy conversion device.

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