Method, device and equipment for calculating hydrodynamic characteristics of flexible Bragg submerged dike based on frequency band control and computer storage medium

Abstract

A method, device and equipment for calculating hydrodynamic characteristics of a flexible Bragg submerged dike based on frequency band control and a computer storage medium relate to the technical field of coast and ocean engineering, and the method comprises the following steps: constructing a flexible structure-water wave complete coupling mathematical model; the structural natural vibration frequency and the Bragg resonance frequency of the flexible Bragg submerged dike are calculated to determine a core wave absorption frequency band, and frequency band control conditions of the flexible Bragg submerged dike are formed; weighting the transmission coefficient, the energy loss and the wave load on the basis of a frequency band control condition in combination with a target sea condition spectrum to form a comprehensive evaluation factor, and representing the comprehensive wave dissipation performance and the structural stress performance of the submerged dike; according to the scheme provided by the invention, the hydrodynamic characteristics of the flexible Bragg submerged embankment can be accurately calculated, a scientific basis is provided for reasonable design and arrangement of the flexible Bragg submerged embankment in ocean engineering, and the wave dissipation performance and comprehensive benefits of the submerged embankment are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coastal and marine engineering, and in particular to a calculation method, device, equipment and computer storage medium for water dynamic characteristics of a flexible Bragg submerged dike based on frequency band control. BACKGROUND

[0002] In marine engineering, a submerged dike is a core structure for coastal protection and marine environment improvement, and its water dynamic characteristics directly determine the protection efficiency and engineering benefits. The traditional rigid submerged dike has three major drawbacks: first, it greatly interferes with the marine ecology and easily blocks the connectivity of the sea area, leading to unbalanced sediment deposition; second, it has high material consumption, high construction cost and large foundation bearing pressure; and third, it has a narrow wave dissipation frequency band and is only effective for specific wavelength waves, making it difficult to adapt to complex sea wave conditions.

[0003] With the development of the concept of ecological marine engineering, the flexible Bragg submerged dike has become a research hotspot due to its advantages of "resonance wave dissipation + flexible adaptation". Based on the principle of wave Bragg resonance, it realizes wave energy reflection and dissipation through multi-structure cooperation, and the flexible structure can reduce the destruction to marine habitats. However, the existing technology has three major bottlenecks: first, there is a lack of accurate water dynamic characteristic calculation model, the traditional boundary element model does not consider the complete coupling of flexible structure and water wave, and cannot quantify the composite wave dissipation mechanism of "structure natural vibration - resonance cooperation"; second, there is no special calculation device, relying on general simulation software, which has low calculation efficiency and is difficult to adapt to actual sea area parameters; third, the arrangement scheme lacks scientific basis, and the matching relationship between structure parameters (such as spacing and filling degree) and frequency band control is not clear, resulting in unstable wave dissipation efficiency in engineering application.

[0004] Therefore, developing a flexible Bragg submerged dike water dynamic characteristic calculation method, special device and optimized arrangement scheme that can realize active control of frequency band has become the key to solving the pain points of existing technology and promoting the engineering application of flexible submerged dike. SUMMARY

[0005] The embodiments of the present application provide a calculation method, device, equipment and computer storage medium for water dynamic characteristics of a flexible Bragg submerged dike based on frequency band control, to accurately calculate the water dynamic characteristics of a flexible Bragg submerged dike, provide a scientific basis for its reasonable design and arrangement in marine engineering, and improve the wave dissipation performance and comprehensive benefits of the submerged dike.

[0006] The calculation method for water dynamic characteristics of a flexible Bragg submerged dike based on frequency band control comprises: establishing a flexible structure-water wave complete coupling mathematical model; Based on the above mathematical model, the characteristic function expansion method is used to represent the wave incident, reflection and transmission boundary conditions in the inlet / outlet domain, and the boundary element method and finite difference method are coupled to solve in the middle domain, to obtain the flow field velocity potential distribution, flexible membrane response and hydrodynamic characteristic parameters; Based on the hydrodynamic characteristic parameters, the natural frequency of the flexible Bragg submerged breakwater structure is calculated With the Bragg resonance frequency , and the frequency band control index is defined ; Based on determine the core wave absorption frequency band , form the frequency band control condition of the flexible Bragg submerged breakwater; Based on the frequency band control condition combined with the target sea state spectrum, the transmission coefficient, energy loss and wave load are weighted to form the comprehensive evaluation factor to represent the comprehensive wave absorption performance and structural stress performance of the submerged breakwater; Optimization in the structure and arrangement parameter space makes the comprehensive evaluation factor The arrangement scheme is obtained by minimizing the comprehensive evaluation factor.

[0007] Further, the control equation and boundary condition describing the fluid velocity potential function and the dynamic response of the flexible membrane structure are obtained through the complete coupling mathematical model of the flexible structure-water wave.

[0008] Further, wherein the core wave absorption frequency band is defined as: ; In the formula, is the natural frequency of the Bragg submerged breakwater structure, is the Bragg resonance frequency of the Bragg submerged breakwater structure, is the frequency band control index, is the core wave absorption frequency band, wherein is the lower limit frequency of the core wave absorption frequency band, is the upper limit frequency of the core wave absorption frequency band.

[0009] Further, the number of submerged breakwaters , the distance between adjacent submerged breakwaters , wherein is the distance between adjacent submerged breakwaters, is the order of Bragg scattering, is the wavelength corresponding to the spectral peak frequency.

[0010] Further, the structural parameters of the flexible Bragg submerged breakwater are: relative density , is the structural density / seawater density, the degree of filling , is the actual liquid volume / maximum design volume, the relative internal pressure , = internal pressure / seawater static pressure, relative radius , rR is the radius of the submerged dike / water depth.

[0011] Further, the material of the flexible Bragg submerged dike is polyurethane film, the elastic modulus , Poisson's ratio .

[0012] The computing device for the hydrodynamic characteristics of the flexible Bragg submerged dike based on frequency band control comprises: A model construction module is configured to receive user input of the calculation domain boundary conditions, wave conditions and flexible Bragg submerged dike structure parameters, automatically generate a flexible Bragg submerged dike hydrodynamic calculation model using the characteristic function expansion method in the in / out domain and the boundary element method and finite difference method coupled solution in the middle domain. A calculation analysis module is in communication connection with the model construction module and is configured to solve the fully coupled equation of the flexible Bragg submerged dike and the wave based on the flexible Bragg submerged dike hydrodynamic calculation model to obtain the hydrodynamic characteristic parameters of the submerged dike, including the reflection coefficient , the transmission coefficient , the energy loss coefficient , the wave action force, the structural natural frequency , the Bragg resonance frequency and the frequency band control index . An optimization decision module is in communication connection with the calculation analysis module and is configured to optimize the submerged dike structure parameters based on the comprehensive evaluation factor , generate recommended optimal design parameters and corresponding performance curves. A data management module is in communication connection with the optimization decision module and is configured to store the user input data, calculation results and optimization results, and is further configured to query, historically compare and export data.

[0013] The computing device for the hydrodynamic characteristics of the flexible Bragg submerged dike based on frequency band control comprises at least one processor, at least one memory and computer program instructions stored in the memory, which realize the above-mentioned method when executed by the processor.

[0014] A computer readable storage medium having computer program instructions stored thereon, which realize the above-mentioned method when executed by a processor.

[0015] The above-mentioned technical solutions provided by the embodiments of the present application have at least the following beneficial effects: 1. By conducting theoretical modeling and calculating breakwater evaluation factors, design parameters for flexible Bragg submersible breakwaters suitable for actual sea areas are obtained, and the wave Bragg resonance principle is used to achieve wave dissipation.

[0016] 2. Compared with traditional rigid breakwaters, the flexible Bragg submersible breakwater obtained by this solution has many advantages. First, its construction is quick, saving not only time and costs but also reducing the input of manpower and materials. Second, due to the use of flexible materials, it has good environmental protection properties and will not have an adverse impact on the marine ecological environment. Most importantly, this flexible Bragg submersible breakwater does not impact the environment while dissipating waves, effectively reducing siltation and protecting the stability of the coastline.

[0017] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 A schematic diagram of the construction framework for a numerical wave flume; Figure 2 A schematic diagram illustrating the mathematical model calculation of the Flexible Bragg Breakwater (BSFMB); Figure 3 For three flexible Bragg dikes (BSFMB) With dimensionless wavelength A diagram illustrating the changes; Figure 4 For three flexible Bragg dikes (BSFMB) With dimensionless wavelength A diagram illustrating the changes; Figures 3-4 The parameters in are: ( ); Figure 5 Modal variations of flexible Bragg breakwater (BSFMB) under wave action at different frequencies Figure 1 ; Figure 6 Modal variations of flexible Bragg breakwater (BSFMB) under wave action at different frequencies Figure 2 ; Figure 7 Modal variations of flexible Bragg breakwater (BSFMB) under wave action at different frequencies Figure 3 ; Figure 8 Modal variations of flexible Bragg breakwater (BSFMB) under wave action at different frequencies Figure 4 ; Figure 9 Modal variations of flexible Bragg breakwater (BSFMB) under wave action at different frequencies Figure 5 ; Figure 10 Modal variations of flexible Bragg breakwater (BSFMB) under wave action at different frequencies Figure 6 ; Figure 11 Modal variations of flexible Bragg breakwater (BSFMB) under wave action at different frequencies Figure 7 ; Figure 12 Modal variations of flexible Bragg breakwater (BSFMB) under wave action at different frequencies Figure 8 ; Figure 13 Modal variations of flexible Bragg breakwater (BSFMB) under wave action at different frequencies Figure 9 ; Figure 14 A schematic diagram illustrating the interaction between waves and the flexible Bragg breakwater (BSFMB); Figure 15 For different numbers of flexible Bragg dikes (BSFMB) With dimensionless wavelength A diagram illustrating the changes; Figure 16 For different numbers of flexible Bragg dikes (BSFMB) With dimensionless wavelength A diagram illustrating the changes; Figures 15-16 The parameters in are: ( ); Figure 17 For different spacing Down, With dimensionless wavelength Diagram of changes Figure 1 ; Figure 18 For different spacing Down, With dimensionless wavelength Diagram of changes Figure 2 ; Figure 19 For different spacing Down, With dimensionless wavelength Diagram of changes Figure 1 ; Figure 20 For different spacing Down, With dimensionless wavelength Diagram of changes Figure 2 ; Figures 17-20 The parameters in are: ( ); Figures 21-24 For the Flexible Bragg Breakwater (BSFMB) With dimensionless wavelength A diagram illustrating the changes; Figure 22 For the Flexible Bragg Breakwater (BSFMB) With dimensionless wavelength A diagram illustrating the changes; Figure 23 For the Flexible Bragg Breakwater (BSFMB) With dimensionless wavelength A diagram illustrating the changes; Figure 24 For the Flexible Bragg Breakwater (BSFMB) With dimensionless wavelength A diagram illustrating the changes; Figures 21-24 The parameters in are: ( ). Detailed Implementation

[0020] 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 so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0021] Example 1 This scheme uses the boundary element model expanded by characteristic functions as its core to achieve accurate calculation of the hydrodynamic characteristics of a flexible Bragg breakwater. The specific steps are as follows: Step 1: Construct a fully coupled mathematical model of flexible structure and water waves.

[0022] The theoretical modeling process, the core of which involves using the boundary element method to calculate the structural hydrodynamic characteristics under arbitrary parameters, is as follows: Figure 1 As shown.

[0023] A hydrodynamic mathematical model capable of solving multiphase fluid interactions is established based on the Boundary Element Method (BEM). A thin-film structure solver is coupled to this model, and a "liquid-film-liquid" coupling method is used to solve the wave-film interaction. The framework structure for constructing the fluid-structure coupled numerical wave tank is as follows: Figure 1 As shown, the flow field solution is based on BEM, the structure solution is based on FDM, the free surface uses inverse Fourier transform and phase inversion, the model solution is based on the BEM-FDM algorithm, the different phase fluids are solved using a multi-subdomain partitioning coupling algorithm, and a wave module is constructed using the characteristic function expansion method and far-field radiation conditions to realize wave generation and wave dissipation. The framework of the fluid-structure coupled numerical wave tank is a realization of a fully coupled mathematical model of flexible structure and water waves. Its core is full fluid-structure coupling; the fluid part uses the boundary element method (BEM), and the structural part uses the finite difference method (FDM). It comprises five modules: the flow field solver (BEM) for the fluid part, the structural solver (FDM) for the flexible membrane part, boundary treatment (free surface Fourier inversion + BEM-FDM coupling) for the coupling conditions of the mathematical model, multiphase flow solution (liquid phase partitioning) for considering water-air or multi-liquid layer boundary condition extension, and the wave module (eigenfunction matching + far-field radiation) for handling infinitely far boundaries. Specific solution methods are as follows: Figure 2 shown.

[0024] Figure 2 A schematic diagram of the mathematical model calculation for a flexible Bragg breakwater is shown, in which the interior of the flexible Bragg breakwater is filled with a density of The fluid is encapsulated by a flexible membrane.

[0025] like Figure 2 As shown, The amplitude of the incident wave; The height of the incident wave; The period of the incident wave; For water depth; Indicates the length of the flexible submerged breakwater; This indicates the distance between two adjacent flexible submerged dikes; Indicates the number of submerged dikes; the external fluid density is set to... The initial static pressure of the fluid inside the membrane is ; and These are the reflected and transmitted wave heights, respectively; For the wave inlet boundary, For the wave exit boundary; It is an impermeable boundary at the bottom of the water; The boundary between the thin film and the external fluid. The boundary where the membrane meets the seabed; This is the boundary of the free water surface.

[0026] Considering the problem is linear, the velocity potential can be expressed as: ,in, is the real part of the complex number; It is the angular frequency; ; The complex amplitude of the velocity potential is used to divide the entire flow field into: ( (Number of flexible Bragg dikes) subdomains ( The velocity potentials of each subdomain are respectively () );in and This refers to the area where waves enter and exit. It is the inner region near the structure. This is the region where the flexible Bragg dike is located. Specifically, in the following text, the membrane radius... This refers to the membrane radius corresponding to the formation of a semi-circle when the flexible Bragg dam is in place; fullness. This refers to the ratio of the arc-shaped area formed by the thin film to the corresponding maximum area (the semi-circular area formed by the thin film), and its range is... .

[0027] in, Under linear wave theory, velocity potential The following governing equations and boundary conditions should be satisfied: (0.1) The linearized free surface condition is written as: (0.2) in The impermeable boundary condition is written as: (0.3) For thin films, the boundary conditions must satisfy: (0.5) (0.6) in, , , P D Indicates the dynamic pressure of the internal and external fluids. E For elastic modulus, Δ Indicates film thickness. Θ S This represents the angle of a thin film unit under static equilibrium conditions. L m Indicates the total length of the film. wThis represents the displacement in the direction of the outer normal of the thin film unit. R Represents the radius of curvature of the thin film unit. T S This represents the tension of a thin film under static equilibrium conditions.

[0028] The far-field radiation conditions for waves are: (0.7) (0.8) Due to the irregular shape of the breakwater and the existence of second-order differential terms in the motion equations of the curved membrane, analytical methods are difficult to use. Therefore, a boundary element model (BEM) is employed to provide a semi-analytical solution to the problem. Specifically, the wave inlet and outlet boundary conditions are given based on the characteristic function expansion method, and the boundary value problem of the inner domain is transformed into an integral equation using the BEM. To reduce computational costs and improve model accuracy, [further details are needed]. ? and? ? Located at a depth of 4 times the water depth outside the breakwater, the corresponding wave inlet and outlet velocity potential functions are expressed as: (0.9) (0.10) in, R m , , T m ( m = 0, 1, 2,...) are undetermined coefficients. k m ( m (=0, 1, 2,...) satisfies the following relationship: (0.11) in, k 0 Let be a real number, representing the wave number; k m (m = 1,2,…) are imaginary numbers, where , It is an equation The real positive root of .

[0029] Vertical characteristic function f(k) m ,z) (m = 0, 1, 2,...) can be written as: (0.12) The inner product of vertical eigenfunctions is defined as follows: (0.13) in:

[0030] The unknown coefficients can be obtained by utilizing the orthogonality of the characteristic functions. R m and T m as follows: (0.14) (0.15) in, Indicates the expanded terms m = M The speed potential at that time will R m and T m Substituting into the import / export boundary conditions, we get:

[0031] In summary, we have given the boundary conditions for the entire solution domain, and these boundary conditions depend only on the velocity potential; all other unknowns are known. Using Green's second theorem, the solution to the Laplace equation can be transformed into the following boundary integral equation: (0.18) in, It is the source point. Indicates the fixed angle factor; Represents the boundary of the solution domain, has directionality, and is defined along... Γ When moving in the positive direction, the solution domain is always located on the left-hand side; Let represent the Green's function that satisfies the Laplace equation, and it is written as: (0.19) (0.20) in, , n Indicates the direction of the outer normal of the element.

[0032] Step 2: Calculate hydrodynamic characteristic parameters Wave transmission coefficient K t and reflection coefficient K r The definition is as follows: (0.21) (0.22) Similarly, energy loss K d The definition is as follows: (0.23) Wave forces on the submerged breakwater F It can be expressed as the integral of the pressure on the object's surface over the membrane boundary: (0.24) In the formula, n = ( n x ，n z ) represents the unit normal vector of the object's surface; For horizontal wave force, This is the vertical wave force.

[0033] Figures 17-20 Different spacings are shown Down, , With dimensionless wavelength A schematic diagram of the changes, in which the effective range for wave Bragg resonance is: ( The distance between the submerged dikes, Indicates the wave wavelength. (These can be 1, 2, 3...); generally speaking, in At this time, the breakwater has the best wave-damping effect, so it is the main consideration in the design. .Will By setting the wave wavelength to the peak frequency of the wave spectrum, the maximum spacing of the breakwater can be calculated. ) and minimum spacing ), Figures 21-24 The flexible Bragg dike is shown. , and different locations and With dimensionless wavelength A diagram illustrating the changes.

[0034] Quantization of frequency band control parameters: Calculation of the first-order natural frequency of the structure based on hydrodynamic characteristics. With the first-order Bragg resonance frequency Difference Determine the core damping frequency band ,in, , .

[0035] Using the above equations, the hydrodynamic characteristics of the flexible Bragg breakwater can be calculated.

[0036] like Figure 3 and 4As shown, based on the calculated hydrodynamic parameters of the structure, it can be seen that the wave-damping effect of the flexible structure is far superior to that of the rigid structure. Furthermore, the first-order Bragg resonance frequency of the flexible Bragg breakwater is mainly located at... The position of the structure's first-order resonant frequency is located at... about.

[0037] Figures 5-13 A schematic diagram illustrating the modal changes of a flexible Bragg breakwater under wave action at different frequencies is shown. It can be seen that in the transition mode, the deformation of the flexible Bragg breakwater is no longer a standing wave; its vibration is a superposition of standing and traveling waves. At different stages, the positions of the intersection points of the dynamic and static boundaries of the flexible Bragg breakwater gradually change, and the corresponding number of intersection points also changes with the wave frequency. When the flexible Bragg breakwater is in the transition mode, the structural response is dominated by the corresponding lower-order modes, gradually transitioning to higher-order modes with increasing frequency. It was found that with increasing relative water depth... As the resonant increases, the resonant point located at the center of the flexible Bragg dike gradually splits into two parts and moves toward the bottom of the flexible Bragg dike.

[0038] Specifically, when the flexible Bragg breakwater is in its first-order resonant mode, the number of dynamic and static boundary intersections is 3 at all phases. The deformation of the flexible Bragg breakwater at each phase passes through the corresponding resonant nodes. However, as the wave frequency increases, the number of dynamic and static shape intersections at different phases is no longer equal (located at the bottom, near the middle, and near the bottom). Overall, the even-order resonant modes of the flexible Bragg breakwater mainly exhibit symmetrical motion about the z-axis, while the odd-order resonant modes mainly exhibit antisymmetric motion about the membrane center. With changes in wave frequency, the deformation of the flexible Bragg breakwater continuously transitions between symmetrical and antisymmetric modes.

[0039] Step 3: Comprehensive evaluation calculation of structural hydrodynamic characteristics By comprehensively considering the effects of structural stress, wave dissipation characteristics, structural dimensions, and structural spacing, a comprehensive evaluation system is established, and the relevant evaluation equations are as follows: Based on the obtained transmission coefficient Energy dissipation coefficient Horizontal wave forces received by each structure ( (representing the number of flexible submerged breakwaters) and vertical wave force ( The number of flexible submerged breakwaters is used, and the average of the design high water level and the design low water level is used as the water depth for calculation to obtain the comprehensive evaluation factor of the flexible Bragg submerged breakwater. :

[0040] in: This represents the wave transmission coefficient. The spectral density function represents an irregular wave. Indicates the amplitude of the component wave. Indicates fluid density, Indicates the number of breakwaters. Represents gravitational acceleration. Indicates water depth. Indicates frequency, and These represent the upper and lower limits of the wave frequencies most likely to occur in the actual ocean.

[0041] In actual calculations, it is assumed that A spectrum satisfying the JONSWAP standard can be represented as: , ; in, The frequency of the spectral peak. Let be the spectral peak period. In the following calculations, assume the effective wave height. ; ; ; ;frequency The range is Spectral peak frequency H Z Number of waves .

[0042] Using the above equation, when the water depth Determine the number of breakwaters Breakwater spacing Structural dimensions When initially determined, the maximum was calculated. That is the optimal design solution.

[0043] Example 2 A computational device for the hydrodynamic characteristics of a flexible Bragg breakwater based on frequency band control includes: Model building module: Provides a visual interface. After the user inputs the boundary conditions of the computational domain (such as incident wave height, period, number of flexible Bragg dikes, spacing, fullness, relative density, relative internal pressure, and size), the system automatically generates a boundary element model with feature function expansion, eliminating the need for manual modeling.

[0044] The computational analysis module integrates three core tools, all of which support parallel computing (up to 16 threads). It also integrates a coupled equation solver, a hydrodynamic parameter calculator, and a frequency band analysis tool, providing real-time output of the reflection coefficient. Transmission coefficient Parameters such as natural frequency.

[0045] The computational analysis module includes: A coupled equation solver is used to solve the fluid velocity potential function and the dynamic equations of the flexible membrane structure in a coupled manner.

[0046] Hydrodynamic parameter calculator, used to calculate reflection coefficient, transmission coefficient, energy loss coefficient and wave force.

[0047] Frequency band analysis tools are used to calculate the natural frequency, Bragg resonance frequency, and frequency band control parameters of the submerged embankment.

[0048] Optimize decision-making module: based on comprehensive evaluation factors Automatically recommends optimal structural parameters (such as spacing) (relative radius), and generate , and , The relationship curve between wave number and water depth can aid in decision-making.

[0049] The optimization decision-making module is based on a weighted comprehensive evaluation factor of wave dissipation performance and structural stress. Output the product of the submerged breakwater spacing and the wave number minus the water depth. Transmission coefficient curves and reflection coefficient curves under the relationship.

[0050] Data Management Module: Supports data querying and data storage categorized by "Calculation Date - Sea Area Name - Submerged Breaker Number," and supports multi-condition queries. Data export supports Excel (.xlsx format, including original parameters, calculation results, and curve data), and also provides a "Historical Comparison" function, which allows users to select 2-5 sets of data to generate comparison tables / line graphs, facilitating project review (such as comparing the maximum displacement differences between different batches of submerged breakers).

[0051] Hardware module of the computing device for the hydrodynamic characteristics of the flexible Bragg submerged breakwater based on frequency band control To address the complex environments of real-world marine environments (such as tidal changes, salt spray erosion, and water flow impact), the hardware modules employ an anti-interference and highly durable design to ensure the stability of data acquisition and processing. The specific operational procedures have been optimized as follows: 1. Data collection adapted to marine environments: A sensor suite, including a pressure wave height meter, stress strain gauge, geometric measuring instrument, and acoustic Doppler current meter, automatically collects data at fixed 10-minute intervals, in conjunction with the tidal cycle and wave variation patterns of the sea area. It also features a "tide-triggered acquisition" mode (automatically shortening the acquisition interval to 5 minutes when the tide level change exceeds 0.5m). The acquisition process is designed to be adaptable to the surrounding environment. For data transmission, the collected data is transmitted via a 4G / 5G wireless module housed in a waterproof signal box (equipped with a desiccant to prevent moisture damage). In the event of a signal interruption, the data is automatically stored in the sensor's local cache (cache capacity ≥16GB, capable of storing 72 hours of data), and retransmitted once the signal is restored.

[0052] 2. Data Processing: A high-performance workstation (multi-core processor + large-capacity memory) runs the calculation program (dustproof and salt spray-proof design, suitable for placement in a temporary on-site computer room or shore monitoring station); Addressing the volatility of marine data, outlier filtering is performed first (e.g., wave height exceeding sensor range, sudden flow velocity drops to 0, etc., data are marked as invalid), followed by smoothing using a moving average method (window size of 5 sampling points) to reduce interference from tides and instantaneous currents; Simultaneously, consistency verification is performed on submerged breakwater parameter data (e.g., the matching of relative internal pressure and filling degree; when filling degree > 0.95, relative internal pressure should be within the range of 0.09-0.11 bar, exceeding this range indicates an anomaly); The software module's model building function is automatically invoked, substituting actual parameters collected on-site (e.g., wave height 1.2m, period 8s, water depth 8m in a certain collection) to generate a boundary element model of characteristic functions fully adapted to the on-site conditions, without requiring manual adjustment of model parameters; The coupled equation solver is run, considering the on-site wave-current coupling effect, to output complete hydrodynamic characteristic parameters: reflection coefficient. (e.g., 0.42, reflecting the wave reflection capability of the submerged breakwater), transmission coefficient (e.g., 0.28, to assess the extent to which waves penetrate a submerged breakwater), energy loss coefficient (e.g., 0.71, reflecting the wave dissipation efficiency of the submerged breakwater), horizontal wave force (e.g., 125kN, guiding the design of submerged dikes against horizontal loads), vertical wave force (e.g., 86kN, optimize the bearing capacity of the submerged dike foundation), maximum displacement (e.g., 0.05m, to verify the rationality of the flexible deformation of the submerged dike), the calculation results are automatically synchronized to the data storage module to avoid data loss.

[0053] 3. Data Storage and Output: Encrypted cloud storage is used, with daily dual backups (local backup to the workstation's internal hard drive, and off-site backup to an Alibaba Cloud off-site server). A backup and recovery test is performed monthly to prevent data corruption or loss. User access requires dual authentication (account and password + mobile verification code), with tiered access permissions for different roles (e.g., engineers can view complete data, while construction personnel can only view parameter results) to ensure data privacy. Output results can be in the form of a data table (including parameter name, value, unit, and precision, such as "reflection coefficient"). : 0.42±0.01”), bar chart (for intuitive comparison) , , The system includes numerical relationships and displacement curves (showing the trend of maximum displacement of the submerged breakwater over 24 hours); it supports connecting to an industrial printer to print paper reports, or exporting data files in Excel / PDF format via USB interface (file naming format is "Sea Area Name-Date-Breakwater Number" for easy archiving).

[0054] Example 3 Implementation process of the layout scheme of the flexible Bragg submersible breakwater Based on the above calculation methods and device outputs, this layout scheme achieves optimization in three aspects: planar layout, structural design, and functional coupling, as detailed below: 1. Floor plan layout 1.1 Number and spacing of submerged breakwaters: Based on the calculated hydrodynamic characteristics and the wave dissipation requirements of the project, the number and spacing of submerged breakwaters are determined. It is assumed that the project requires reducing the wave transmission coefficient in a specific frequency band. After reducing it to below 0.3, and following calculations and analysis, such as... Figures 15-16 As shown, the number of submerged dikes is set. (The first dike is the main load-bearing structure and requires enhanced protection. Based on the test results, in...) (To achieve better results), the arrangement is made at equal intervals. Satisfy: When the target wave-dissipating wavelength is hour, , This indicates the wavelength corresponding to the spectral peak frequency, ensuring that the Bragg resonance condition is met; simultaneously controlling... To achieve coordinated wave dissipation through "structural self-vibration – wave resonance"; 1.2 Arrangement direction: The axis of the submerged breakwater is perpendicular to the main direction of the incident wave, with a deviation angle of ≤5° to reduce the influence of wave diffraction; the projection overlap of adjacent submerged breakwaters is ≤10% to avoid structural interference.

[0055] 1.3 Layout Strategy: Following the principle of equal spacing, the locations of the submersible breakwaters are marked on the seabed. Underwater positioning equipment, such as a GPS underwater positioning system, is used to ensure the accuracy of the breakwater placement. During the layout process, the installation angle and verticality of the breakwaters are strictly controlled to ensure their normal operation. Figure 14 A schematic diagram of the interaction between waves and a flexible Bragg breakwater is shown.

[0056] 2. Structural parameter optimization scheme 2.1 Flexible Submerged Breakwater Design: When fabricating the flexible Bragg breakwater, its structural parameters are strictly controlled. After fabrication, the breakwater is transported to the deployment location and installed using specialized equipment. During installation, the structural integrity of the breakwater is checked to ensure that it will not suffer damage during use.

[0057] Material selection: High-elasticity polyurethane film (elastic modulus) is used. Poisson's ratio ), ensuring flexibility and durability; Key parameter: relative density ( =Structural density / seawater density), fullness ( =Actual filling volume / Maximum design volume), relative internal pressure ( =Internal pressure / Seawater static pressure), relative radius =0.4-0.6 (rᵣ=radius of submerged dike / water depth); 2.2 Reinforced Design of the First Dyke: The first dam adopts a double-layer membrane structure (inner layer of reinforcing fiber, outer layer of polyurethane), with high bending stiffness. It is 20%-30% better than other submerged breakwaters, and its wave load resistance is increased by more than 40%.

[0058] In the first example, the inner reinforcing fiber is made of aramid fiber cloth, which has high strength, high modulus and impact resistance, and can effectively resist wave impact and tensile deformation. The outer material is cast polyurethane elastomer with a thickness of 5~10 mm, which has the properties of seawater corrosion resistance, wear resistance and UV resistance, ensuring the sealing and flexibility of the overall structure.

[0059] In the second example, the inner reinforcing fiber is glass fiber fabric, which has good tensile strength and water resistance and low cost. The outer material is a sprayed polyurethane coating with a thickness of 3-6 mm, forming a polymer protective layer on the surface, which has both flexibility and aging resistance.

[0060] 3. Coordinated scheme for frequency band control and wave suppression 3.1 Broadband wave suppression strategy: through multi-structure mode coupling ( ), expanding the core damping frequency band to (unit: This enables gradual dissipation of medium and long wavelengths; 3.2 Long-wave energy conversion: Controlling the spacing between submerged dikes (L is the long wavelength), which induces the long wavelength energy to be converted into second and third order higher modes.

[0061] After the submersible breakwater is installed, it is monitored and evaluated. Monitoring equipment, such as wave meters and current meters, is installed around the breakwater to monitor its wave-damping effect and changes in hydrodynamic characteristics in real time. The monitoring data is analyzed periodically to assess the breakwater's operational status, and adjustments and maintenance are carried out promptly if problems are found. A computing device for the hydrodynamic characteristics of a flexible Bragg breakwater based on frequency band control includes: at least one processor, at least one memory, and computer program instructions stored in the memory, which implement the above-described method when the computer program instructions are executed by the processor.

[0062] A computer-readable storage medium having stored thereon computer program instructions that, when executed by a processor, implement the above-described method.

[0063] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

Claims

1. A calculation method for the hydrodynamic characteristics of a flexible Bragg submerged breakwater based on frequency band control, characterized in that, include: Establish a fully coupled mathematical model of flexible structure and water waves; Based on the above mathematical model, the characteristic function expansion method is used to represent the boundary conditions of wave incidence, reflection and transmission in the ingress / outgress domain, and the boundary element method and finite difference method are coupled in the intermediate domain to obtain the flow field velocity potential distribution, flexible membrane response and hydrodynamic characteristic parameters. Calculation of the natural frequency of the flexible Bragg breakwater structure based on hydrodynamic characteristic parameters With Bragg resonance frequency and define frequency band control indicators. ; based on Determine the core damping frequency band This forms the frequency band control conditions for a flexible Bragg submerged dike; Based on frequency band control conditions and the target sea state spectrum, a comprehensive evaluation factor is formed by weighting transmission coefficient, energy loss, and wave load. To characterize the overall wave dissipation performance and structural stress performance of the submerged breakwater; Optimize within the structural and layout parameter space to improve the comprehensive evaluation factors. The minimum possible layout scheme is obtained.

2. The method as described in claim 1, characterized in that, The governing equations and boundary conditions describing the fluid velocity potential function and the dynamic response of the flexible membrane structure are obtained through a fully coupled mathematical model of flexible structure and water wave.

3. The method as described in claim 1, characterized in that, in, The core damping frequency band is defined as follows: ； In the formula, The natural frequency of the Bragg dike structure. The Bragg resonance frequency of the Bragg submerged dike structure. For frequency band control indicators, The core damping frequency band, among which, The lower limit frequency of the core suppression band. This is the upper limit frequency of the core suppression frequency band.

4. The method as described in claim 1, characterized in that, Number of submerged dikes Spacing between adjacent submerged dikes In the formula, The distance between adjacent submerged dikes. Let be the order of the Bragg reflection. The wavelength corresponds to the spectral peak frequency.

5. The method as described in claim 1, characterized in that, The structural parameters of the flexible Bragg breakwater are: relative density , Structural density / seawater density, fullness , Actual filling volume / maximum design volume, relative internal pressure , =Internal pressure / seawater static pressure, relative radius , rᵣ is the radius of the submerged dike / water depth.

6. The method as described in claim 1, characterized in that, The flexible Bragg breakwater is made of polyurethane membrane with an elastic modulus of [missing value]. Poisson's ratio .

7. The method as described in claim 1, characterized in that, The first dike of the flexible Bragg submerged breakwater array adopts a double-layer membrane structure, with the inner layer made of reinforcing fibers and the outer layer made of polyurethane.

8. A computational device for the hydrodynamic characteristics of a flexible Bragg breakwater based on frequency band control, employing the method described in any one of claims 1 to 7, characterized in that, include: The model building module is used to receive user input of computational domain boundary conditions, wave conditions, and flexible Bragg breakwater structural parameters, and automatically generate a flexible Bragg breakwater hydrodynamic calculation model that uses the characteristic function expansion method to represent the ingress / exgress domain and the boundary element method and finite difference method to solve the intermediate domain. The calculation and analysis module, communicatively connected to the model building module, is used to solve the fully coupled equations of the flexible Bragg breakwater and waves in parallel based on the hydrodynamic calculation model of the flexible Bragg breakwater, thereby obtaining the hydrodynamic characteristic parameters of the breakwater, including the reflection coefficient. Transmission coefficient Energy loss coefficient Wave forces and structural natural frequencies Bragg resonance frequency and frequency band control indicators ; The optimization decision-making module communicates with the calculation and analysis module to optimize decisions based on comprehensive evaluation factors. The structural parameters of the submerged breakwater are optimized to generate recommended optimal design parameters and corresponding performance curves. The data management module communicates with the optimization decision module and is used to store the user input data, calculation results and optimization results. It is also used for querying, historical comparison and data export.

9. A computational device for the hydrodynamic characteristics of a flexible Bragg breakwater based on frequency band control, comprising: At least one processor, at least one memory, and computer program instructions stored in the memory, which, when executed by the processor, implement the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium having computer program instructions stored thereon, characterized in that, When the computer program instructions are executed by the processor, the method described in any one of claims 1 to 7 is implemented.

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