A multi-mode resonant based longitudinal array wave channel structure

Abstract

The application provides a longitudinal array breakwater channel structure based on multimode resonance, which comprises a plurality of channel structures, a single channel structure comprising two walls arranged in parallel and having a certain interval distance, and the two walls respectively having protruding structures with consistent period length, wherein the period length and the width and length of the protruding structures are adjusted according to actual needs. The longitudinal array breakwater channel structure based on multimode resonance can prevent coastal erosion and ensure the smooth passing and parking of ships.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of flood control dam, and particularly relates to a longitudinal array wave channel structure based on multimode resonance. BACKGROUND

[0002] The construction of flood control dam is also increasingly important in urban development. The flood control dam refers to a dam built to prevent river flooding and harm to people's life and property safety, and the main materials are cement, concrete and the like. In flood control of rivers, lakes and ponds, the risk of dam overtopping and dam overtopping often occurs, and temporary dams are often needed to intercept flood in special environment, site, plot or facility. The existing technology is to fill sandbags to pile up temporary dams in emergency. However, such measures have the problems of uneven and irregular sandbag size, uneven piling, poor stability and low firmness.

[0003] It is crucial to scientifically and reasonably develop and construct the coastal port by using the theory of marine engineering. At the same time of the construction of the coastal port, how to prevent the erosion or damage of the wave to the coastal port is accompanied.

[0004] Chinese Patent Application No. CN201520165864.9 discloses a coastal breakwater composed of a shore dike on the water surface and a supporting round pile. When the water wave is incident to the breakwater, Bragg resonance is generated in the periodically arranged vertical cylindrical soil cylinder pile structure to achieve the purpose of wave protection. Chinese Patent Application No. CN201620309541.7 discloses a cross-shaped floating breakwater composed of a plurality of cross-shaped hollow floats made of rubber. The float is attached with a wave breaking rod and is fixed at a specified position by a chain and an anchor base. Due to the arrangement of a plurality of same-shaped floats, the incident water wave will be broken and resonated in the structure to hinder the transmission of the water wave. Chinese Patent Application No. CN201611137592.7 discloses a floating breakwater for eliminating medium and long period waves. The floating breakwater includes a plurality of V-shaped floats arranged in parallel and fixed at a specified position by a gravity anchor at three vertices of the V-shaped float, and can be used to eliminate medium and long period 6-10s waves.

[0005] The above three kinds of wave protection structures all have the problem of hindering the passage of ships. Ships have to bypass the wave protection structure to reach the wave protection area. SUMMARY

[0006] In order to solve the above problems, the present application provides a longitudinal array wave channel structure based on multimode resonance, which is a periodic structure breakwater, and can prevent coastal erosion and ensure smooth passage and berthing of ships.

[0007] According to the technical scheme of the application, a longitudinal array wave-preventing channel structure based on multi-mode resonance is provided, which comprises a plurality of channel structures, each channel structure comprising two parallel walls with a certain interval distance, and each wall having a protruding structure with a consistent period length, wherein the period length can be adjusted according to actual needs.

[0008] Preferably, the protruding structures on the two walls are arranged in a half-period relative displacement staggered manner, and are asymmetrically distributed.

[0009] Further, the period length and the width of the protruding structure can be adjusted according to actual needs. The ratio of the length of the protruding structure on the two walls to the period length, i.e. the duty cycle, can also be adjusted according to actual conditions.

[0010] Preferably, the plurality of channel structures are in a compliant parallel relationship, i.e. when the first channel structure is curved with a certain curvature, the second channel structure adjacent to the first channel structure is curved with a curvature consistent with the curvature of the first channel structure, i.e. in a compliant parallel relationship.

[0011] More preferably, the size parameters of the wave-preventing channel structure need to be designed according to the multi-mode resonance principle and the wave-preventing requirements, and the following formula is used for design and calculation:

[0012]

[0013] wherein c.c. is a conjugate complex, Φ(x, y, z, t) is a velocity potential, φ(x, y) is a horizontal displacement, k is a wave number determined by an angular frequency ω, ω is determined by a water wave linear dispersion relationship, x is a horizontal component, y is a vertical component of x, and z is an orthogonal component perpendicular to the xy plane.

[0014] ω 2 = (gk + yk 3 / ρ) tanh kh

[0015] wherein g is a gravitational acceleration, γ is a water surface tension, and the value is γ = 73 dyn / cm, ρ is a water density, and the value is ρ = 1 g / cm 3 , and h is a water surface to water bottom depth.

[0016] The multi-mode resonance based longitudinal array wave-proof channel structure of the present application can regulate and observe some wave phenomena in the periodic structure by adjusting the geometric parameters of the periodic structure; the periodic structure wave-breaker can make the sea waves form resonance in the wave-break structure, so that the water waves of specific period cannot pass through the periodic structure wave-breaker, forming a forbidden band in the corresponding period range to achieve the purpose of wave-proof. Further, the multi-mode resonance based longitudinal array wave-proof channel structure has the following beneficial effects:

[0017] 1. Simple structure, easy to build;

[0018] 2. Can adapt to various port environments regardless of water depth;

[0019] 3. Strong water wave attenuation and wave absorption capacity;

[0020] 4. While attenuating and hindering water wave propagation, it can also ensure smooth passage and berthing of ships;

[0021] 5. The geometric parameters and the number of periodic structures on the walls of the channel, as well as the number of longitudinal array channels, can be adjusted according to actual needs. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a top view of a multi-mode resonance based longitudinal array wave-proof channel structure according to the present application.

[0023] Figure 2 is an axial side view of the multi-mode resonance based longitudinal array wave-proof channel structure in Figure 1

[0024] Figure 3 is a simulation amplitude field map corresponding to the application of the multi-mode resonance based longitudinal array wave-proof channel structure.

[0025] The reference signs in the drawings are as follows:

[0026] 1. Multi-mode resonance based longitudinal array wave-proof channel structure, 2. Sea level, 3. Coast. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. Additionally, the protection scope of the present application should not be limited to the following specific structures or components or specific parameters.

[0028] ​The application discloses a longitudinal array wave-preventing channel structure based on multimode resonance, which comprises two parallel walls with a certain interval distance, and the two walls are respectively provided with periodically arranged rectangular convex structures with the same geometric size.

[0029] Further, the longitudinal array wave-preventing channel structure based on multimode resonance comprises a plurality of channel structures, and each channel structure comprises two parallel walls with a certain interval distance, and the two walls are respectively provided with rectangular convex structures with the same period length.

[0030] The longitudinal array wave-preventing channel structure based on multimode resonance adopts the excitation theory and mode of high-order modes in wave motion, which is quite different from the low-order modes in wave motion.

[0031] The longitudinal array wave-preventing channel structure based on multimode resonance will be further described below with reference to the drawings. Figure 1The longitudinal array breakwater structure based on multi-mode resonance shown includes a plurality of channel structures in a compliant parallel relationship, that is, when a first channel structure is bent at a certain curvature or curvature, a second channel structure adjacent to the first channel structure exhibits a bend consistent with the curvature of the bend of the first channel structure, that is, a compliant parallel relationship; a single channel structure includes two compliantly parallel walls with a spacing distance b between the two walls, a plurality of rectangular protruding structures are arranged on the two side walls respectively, each rectangular protruding structure has the same protruding structure length w and protruding structure width d, adjacent rectangular protruding structures have the same period length Λ, and the parameters such as the protruding structure length w, the protruding structure width d and the period length Λ can be adjusted according to actual needs. The protruding structures on the corresponding two side walls are arranged asymmetrically, for example, there are corresponding two side walls in the first channel structure, corresponding rectangular protruding structures are arranged on the two parallel side walls respectively, and there is a relative displacement Δx of half a water wave period length between the corresponding rectangular protruding structures arranged on different side walls.

[0032] When the sea waves enter the channel of the longitudinal array breakwater structure based on multi-mode resonance, due to the asymmetry of the periodic structure of the rectangular protruding structure on the two side walls, the rectangular protruding structure can excite multi-mode resonance with high-order transverse modes, and compared with Bragg resonance, the multi-mode resonance has a greater inhibiting and attenuating effect on sea waves. Figure 3 For the application of the corresponding simulation amplitude field diagram of the longitudinal array breakwater structure based on multi-mode resonance, by Figure 3 It can be seen from the field diagram shown that a complex field distribution is formed near the entrance of the channel, and rapidly attenuates along the channel direction. The central period of multi-mode resonance, that is, the central period of breakwater, can be set to the target frequency by adjusting the protruding structure spacing distance b and the protruding structure period length Λ. The width of the multi-mode resonance band, that is, the breakwater frequency band, can be expanded and narrowed by adjusting the protruding structure width d.

[0033] Further, the protruding structures with the same geometric size arranged periodically on the spacing walls in the longitudinal array breakwater structure based on multi-mode resonance can be designed in the shapes of sawtooth, semicircle, trapezoid, etc. according to different application environments. The relative positions of the protruding structures on the walls are different by half a wave period length to realize the asymmetric distribution of the periodic structure on the walls. The channel width in the channel structure and the length, width and period length of the protruding structure can be adjusted according to the sea wave period of the breakwater target, and the ratio of the protruding structure length to the period length on the two side walls, that is, the duty cycle, can also be adjusted according to actual conditions.

[0034] Further, the convex structure is a rigid material with certain hardness, such as reinforced concrete, wherein the thickness of the wall is usually not less than 20 cm. The number of the channel structures in the longitudinal array wave protection channel structure based on multi-mode resonance in the application can be selected according to actual needs, and the number of the channel structures arranged in the longitudinal array can meet the wave protection needs of different application scenarios or occasions.

[0035] The design of each parameter in the longitudinal array wave protection channel structure based on multi-mode resonance in the application needs to be designed according to the principle of multi-mode resonance and the wave protection needs. The following formula is used for design calculation:

[0036]

[0037] wherein c.c. is a conjugate complex, Φ(x, y, z, t) is a velocity potential, φ(x, y) is a horizontal displacement, k is a wave number determined by an angular frequency ω, ω is determined by a water wave linear dispersion relationship, x is a horizontal component, y is a vertical component of the vertical component of x, and z is an orthogonal component perpendicular to the xy plane.

[0038] ω 2 =(gk+γk 3 / ρ)tanhkh

[0039] wherein g is a gravitational acceleration, γ is a water surface tension, the value of which is γ=73 dyn / cm, ρ is a water density, the value of which is ρ=1 g / cm 3 , and h is a water surface depth from the water bottom.

[0040] As shown in the structure shown in Figure 1 , the two side walls of the single channel structure have an asymmetric structure, and the whole of the periodic rectangular convex structure on a single side wall is translated to form an asymmetric structure of the periodic rectangular convex structure on the two sides, wherein the translation distance is half the periodic length of the convex structure.

[0041] Preferably, the implementation of the longitudinal array wave protection channel structure based on multi-mode resonance is as follows:

[0042] The width interval b of the channel between the two side walls of the single wave protection channel structure with an asymmetric structure is 15 m, the periodic length of the convex structure Λ is 15 m, the number of the periodic convex structures is 10, the width d of the rectangular convex structure on the two side walls is 1.2 m, the length w of the convex structure is 6 m, and the duty cycle is 0.4 (i.e. the ratio of the length of the convex structure to the periodic length of the convex structure). The whole of the periodic convex structure on a single side wall is relatively displaced, and the relative displacement length Δx is half the periodic length of the convex structure, i.e. 7.5 m. The number of the longitudinal array channel structures is 5, and the arrangement mode is as shown in Figure 1The two side walls and the protruding structures on the walls can be made of rigid materials, such as reinforced concrete. For different application environments, if the actual demand for the wave-breaking area is larger, the number of the longitudinally arranged wave-breaking channels can be increased to meet the demand for expanding the wave-breaking area.

[0043] Figure 2 The installation of the longitudinally arranged wave-breaking channel structure based on the multi-mode resonance is shown. The longitudinally arranged wave-breaking channel structure 1 is arranged vertically to the sea level 2, and the sea level 2 is located in the longitudinally arranged wave-breaking channel structure 1.

[0044] Figure 3 The simulation amplitude field diagram corresponding to the application of the longitudinally arranged wave-breaking channel structure based on the multi-mode resonance is shown. Figure 1 and Figure 2 The simulation results under the condition of the above-mentioned example size structure are shown.

[0045] Under the condition of the above-mentioned structure size, the simulation software is used to simulate the performance of the longitudinally arranged wave-breaking channel structure. Figure 2 The performance of the longitudinally arranged wave-breaking channel structure corresponding structure is tested. The wave incident source is arranged on one side of the longitudinally arranged wave-breaking channel structure, and the water wave amplitude on the other side of the longitudinally arranged wave-breaking channel structure is observed. The simulation numerical results show that the transmission spectrum of the longitudinally arranged wave-breaking channel structure has an obvious forbidden band in the range of 3.75 s to 4.05 s of the incident wave period, so that the wave-breaking purpose can be achieved.

[0046] Figure 3 The field distribution diagram of the sea wave incident to the longitudinally arranged wave-breaking channel structure in the forbidden band range is shown. It can be seen from the amplitude field distribution that due to the protruding structure on the wall being an asymmetric structure with relative displacement, the high-order mode is excited and multi-mode resonance is generated, the water wave energy is completely dissipated at the front end of the channel, and a more complex physical field distribution is formed. Compared with the traditional Bragg wave-breaking structure, the wave-breaking ability of the wave-breaking channel with the asymmetric structure is better than that of the wave-breaking dike with the symmetric structure.

[0047] In summary, the longitudinally arranged wave-breaking channel structure based on the multi-mode resonance mechanism realizes the functions of attenuating wave energy and ensuring the smooth passage of ships. The longitudinally arranged wave-breaking channel structure has the advantages of simple structure, easy construction, and stronger ability to attenuate and hinder water waves than the traditional Bragg wave-breaking dike, while ensuring the passage space. The scheme in the above-mentioned embodiment is only used to illustrate the implementation mode and wave-breaking performance of the longitudinally arranged wave-breaking channel structure based on the multi-mode resonance. Those skilled in the art know that the structure parameters can be adjusted according to the demand for wave-breaking in actual application.

[0048] The above description is merely a preferred specific embodiment of the present application, and the protection scope of the present application is not limited thereto. Any modification or replacement within the technical scope disclosed by the present application can be easily thought by those skilled in the art, and should be covered within the protection scope of the present application. Those skilled in the art can understand that various modifications can be made in form and details without departing from the spirit and scope of the present application defined by the appended claims.

Claims

1. A multi-mode resonance based longitudinal array breakwater structure, characterized by, It includes multiple channel structures, a single channel structure includes two walls placed in parallel and having a certain interval distance, and the two walls have periodically arranged and same geometric size rectangular protruding structures on both sides; the periodic protruding structures on both sides of the walls are arranged with a half-period relative displacement, showing asymmetric distribution, wherein the period length is adjusted according to actual needs; The ratio of the length of the rectangular protruding structure on both walls to the length of the rectangular period, i.e. the duty cycle, is adjusted according to actual conditions; the two walls of a single channel structure have an asymmetric structure, and the whole rectangular protruding structure period on a single wall is translated to form an asymmetric structure of the two periodic rectangular protruding structures, wherein the translation distance is half the length of the protruding structure period; The size parameters of the wave protection channel structure need to be designed according to the multi-mode resonance principle and wave protection requirements, which are designed and calculated by using the following formula: ； Where c.c. is a conjugate complex, Φ(x,y,z,t) is a velocity potential, φ(x,y) is a horizontal displacement, k is a wave number determined by the angular frequency ω, ω is determined by the water wave linear dispersion relation, x is a horizontal component, y is a vertical component perpendicular to x, and z is a normal component perpendicular to the xy plane; ； where g is the acceleration of gravity, γ is the water surface tension, with a value of γ = 73 dyn / cm, p is the water density, with a value of p = 1 g / cm 3 , and h is the depth of the water surface from the water bottom.

2. The multi-mode resonance based longitudinal array breakwater structure of claim 1, wherein, Multiple channel structures have a compliance parallel relationship, that is, when a first channel structure has a certain curvature or curvature bending, a second channel structure adjacent to the first channel structure has a bending consistent with the curvature of the first channel structure, that is, a compliance parallel relationship.

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