Three-dimensional wave field reconstruction method for typical sea area

Abstract

The invention discloses a three-dimensional wave field reconstruction method for a typical sea area, and the method comprises the steps: carrying out the landform scanning measurement of a target sea area through a single-beam or multi-beam depth finder, or collecting the high-resolution landform data of the target sea area, dividing the target sea area at equal intervals, deploying wave measurement equipment, and carrying out the reconstruction of a three-dimensional wave field of the typical sea area. The wave three-dimensional reconstruction method comprises the following steps of: selecting an appropriate wave numerical model after actual measurement data is analyzed, simulating a wave evolution numerical value, and sorting and analyzing a numerical result to complete the wave three-dimensional reconstruction. According to the method, the three-dimensional wave characteristics of the target sea area grid are effectively obtained, a reconstructed three-dimensional wave field is formed, and effective input is provided for analysis and assessment of motion characteristics of ships, offshore engineering, ocean engineering and near-island engineering in waves; and carrying out wave grid model construction and wave evolution model construction on the basis of multi-point buoy actual measurement deployment and in combination with topographic data, so as to realize three-dimensional wave field reconstruction of typical sea areas.

Description

Technical Field

[0001] The invention belongs to the technical field of ship and ocean engineering, and in particular relates to a three-dimensional wave field reconstruction method of a typical sea area. Background Art

[0002] Waves, as important environmental loads, directly affect the navigation, structural performance and operational capabilities of ships at sea, and are the main input parameters for assessing the safety of ship motion, nearshore engineering and marine structures.

[0003] At present, when assessing the wave resistance performance of various types of ships, offshore projects and marine structures, relevant tests are mainly carried out under specific sea conditions. Among them, waves are mainly measured and obtained through single-point buoys, and the marine environment is usually regarded as a two-dimensional long-peak wave. However, waves in actual sea conditions often have three-dimensional characteristics, so it is impossible to truly obtain the characteristics of the marine environment in the test area. The test results caused by this have a large deviation from the numerical and model test results, which affects the assessment of the actual wave resistance performance of ships, offshore projects and marine structures, and also affects the relevant analysis of models and real objects.

[0004] Existing wave analysis generally uses wave observation data from surrounding ocean observation stations for numerical simulation, or directly uses the results of single-point wave buoy measurements as a reference. However, there is often a certain regional distance between ocean stations or single-point wave buoys and the working sea areas of ships, near-shore projects and marine structures, and the water depth conditions are also quite different. Therefore, this method cannot accurately give the wave characteristics in the actual area. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a three-dimensional wave field reconstruction method of a typical sea area with reasonable design and capable of accurately giving the wave characteristics in the actual area in view of the deficiencies in the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A three-dimensional wave field reconstruction method for a typical sea area is characterized in that the method comprises the following steps:

[0008] (1) Acquisition of target sea area terrain data

[0009] Use single-beam or multi-beam echo sounders to conduct terrain scanning of the target sea area, or collect high-resolution terrain data of the target sea area;

[0010] (2) Wave grid model construction

[0011] The target sea area is divided into equal intervals, with the maximum grid spacing not exceeding 10m×10m, to form a grid suitable for the Boussinesq model and the gentle slope equation model, and the terrain data is interpolated to the grid nodes to obtain the water depth h j , where j is an integer from 1 to M, and M is the number of nodes;

[0012] (3) Deployment of wave measurement equipment

[0013] Deploy N wave measurement devices around the target sea area, among which at least one device can give the main wave direction D of the wave. m , all wave measurement equipment can give the wave energy spectrum S i (f), where f is the frequency and i is an integer from 1 to N corresponding to the corresponding wave measurement equipment;

[0014] (4) Measured wave element reception

[0015] All wave measurement devices are turned on and start measuring at the same time, and send the measurement results to nearby receiving devices at the same time;

[0016] (5) Measured data analysis

[0017] According to the main wave direction D m Select the wave measurement data at the corresponding position as the boundary condition of the wave numerical model. For example, when the main wave is D m When the direction is east, the measurement data of the wave measurement equipment on the east side of the target sea area is selected as the boundary condition. Let the number of the equipment be t, and the corresponding wave energy spectrum be S t (f) According to S t (f) Calculate the average zero-crossing period

[0018]

[0019] Youyi Bogao

[0020]

[0021] (6) Selection of wave numerical model

[0022] According to T z and h j Calculate the wave number k for each node zj

[0023]

[0024] Where g is the acceleration due to gravity, calculate k zj h j , when more than 30% of all nodes have k zj h jWhen <1, the wave numerical model uses the Boussinesq model, otherwise the gentle slope equation model is used;

[0025] (7) Numerical simulation of wave evolution

[0026] S t (f) Applying it to the incident wave boundary corresponding to the wave numerical model to carry out numerical simulation;

[0027] (8) Analysis of numerical results

[0028] According to the simulation results, the energy spectrum S at each node is obtained using the spectrum analysis method. j (f) Calculate the corresponding average zero-crossing period and significant wave height; use the upper zero-crossing algorithm to obtain the maximum wave height and the period corresponding to the maximum wave height of each node, and complete the three-dimensional reconstruction of the wave;

[0029] (9) Obtain the measured wave parameters at the next moment and repeat steps (5) to (7) until the task is completed.

[0030] The technical problem to be solved by the present invention can also be achieved by the following technical solution. In step (1), the scale of the target sea area terrain data must not be greater than 1:2000.

[0031] The technical problem to be solved by the present invention can also be achieved by the following technical solution: the wave measurement equipment described in step (3) includes a buoy and an acoustic Doppler current profiler ADCP.

[0032] The technical problem to be solved by the present invention can also be achieved by the following technical scheme. The deployment of the wave measuring equipment in step (3) is as follows: when there are no islands, reefs or coastlines around, the number N of wave measuring equipment is not less than 4 sets, and they are evenly deployed in the four directions of the target sea area; when there are islands, reefs or coastlines around, no wave measuring equipment is deployed near the islands, reefs or coastlines, and multiple sets of wave measuring equipment are deployed at the other end away from the islands, reefs or coastlines.

[0033] The technical problem to be solved by the present invention can also be achieved by the following technical solution. In step (7), the effective physical duration of the simulation is required to be no less than half an hour.

[0034] Compared with the prior art, the present invention adopts an effective method to obtain the three-dimensional wave characteristics of the target sea area grid, that is, the maximum grid spacing shall not be greater than 10m×10m, to form a reconstructed three-dimensional wave field, which provides effective input for analyzing and evaluating the motion characteristics of ships, near-shore projects, marine projects, and near-island reef projects in waves; and based on the actual deployment of multi-point buoys and combined with terrain data, a wave grid model and a wave evolution model are constructed to achieve the reconstruction of the three-dimensional wave field in a typical sea area. The present invention uses terrain data grid modeling, adopts a multi-point actual measurement deployment method, selects the corresponding actual measured wave point data as input in combination with the wave direction, uses a small and medium-scale sea area wave numerical model for reconstruction, and uses the actual wave data of the remaining points as verification, which effectively guarantees the accuracy of the reconstruction algorithm. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a flow chart of the method for reconstructing three-dimensional wave fields in a typical sea area according to the present invention;

[0036] Figure 2 This is a deployment diagram of several wave measurement devices recommended by the present invention, where the circles in the diagram represent deployment points. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0038] Reference Figure 1 and Figure 2 , a three-dimensional wave field reconstruction method for a typical sea area, the method comprises the following steps,

[0039] Step 1: Obtaining topographic data of the target sea area. Use professional equipment such as single-beam or multi-beam echo sounders to conduct topographic surveys of the target sea area, or collect high-resolution topographic data of the target sea area. The scale of the topographic data of the target sea area must not be greater than 1:2000.

[0040] Step 2: Wave grid model construction. Divide the target sea area into equally spaced grids, requiring the maximum grid spacing to be no greater than 10m×10m, to form a grid suitable for the Boussinesq model and the gentle slope equation model, and interpolate the terrain data to the grid nodes to obtain the water depth h j , where j is an integer from 1 to M and M is the number of nodes.

[0041] Step 3: Deployment of wave measurement equipment. Deploy N wave measurement equipment around the target sea area, such as buoys, ADCP, etc. When there are no islands, reefs, or coastlines around (open sea), the number of wave measurement equipment N is not less than 4 sets, and they are evenly deployed in the four directions of the target sea area; when there are islands, reefs, or coastlines around, no equipment may be deployed near the islands, reefs, or coastlines, and multiple sets of equipment may be deployed at the other end away from the islands, reefs, and coastlines (island and shore sea areas). At least one set of equipment can give the main wave direction D of the wave. m , all wave measurement equipment can give the wave energy spectrum S i (f), where f is the frequency and i is an integer from 1 to N corresponding to the corresponding measurement device.

[0042] Step 4: Measure wave element reception. All devices are set to start measurement at the same time and send the measurement results to nearby receiving devices at the same time.

[0043] Step 5: Measured data analysis. According to the main wave direction D m The wave measurement data at the corresponding position are selected as the boundary conditions of the wave numerical model. m When the direction is east, the measurement data of the measuring equipment on the east side of the target sea area is selected as the boundary condition. Let the number of the equipment be t, and the corresponding wave energy spectrum be S t (f). According to S t (f) Calculate the average zero-crossing period

[0044]

[0045] Youyi Bogao

[0046]

[0047] Step 6: Selection of wave numerical model. z and h j Calculate the wave number k for each node zj

[0048]

[0049] where g is the acceleration due to gravity. Calculate k zj h j , when more than 30% of all nodes have k zj h j When <1, the Boussinesq model is used as the wave numerical model, otherwise the gentle slope equation model is used.

[0050] Step 7: Numerical simulation of wave evolution. t(f) Apply to the incident wave boundary corresponding to the wave numerical model and carry out numerical simulation. The effective physical duration of the simulation is required to be no less than half an hour.

[0051] Step 8: Arrangement and analysis of numerical results. According to the simulation results, the energy spectrum S at each node is obtained by using the spectrum analysis method. j (f) and calculate the corresponding average zero-crossing period and significant wave height; use the upper zero-crossing algorithm to obtain the maximum wave height of each node, the period corresponding to the maximum wave height and other parameters to complete the three-dimensional reconstruction of the wave.

[0052] Step 9: Get the measured wave parameters at the next moment and repeat steps 5 to 7 until the task is completed.

[0053] The three-dimensional wave field reconstruction method of a typical sea area described in the present invention is based on multi-point measured data and combines high-resolution terrain data to construct a wave grid model and apply a wave evolution model, and performs a reasonable and feasible wave environment element analysis on the wave elements in the target area, thereby achieving accurate three-dimensional reconstruction of the wave field in the sea area around the structure to meet engineering needs.

[0054] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A three-dimensional wave field reconstruction method for a typical sea area, characterized in that: The method comprises the following steps, (1) Acquisition of target sea area terrain data Use single-beam or multi-beam echo sounders to conduct terrain scanning of the target sea area, or collect high-resolution terrain data of the target sea area; (2) Wave grid model construction The target sea area is divided into equal intervals, with the maximum grid spacing not exceeding 10m×10m, to form a grid suitable for the Boussinesq model and the gentle slope equation model, and the terrain data is interpolated to the grid nodes to obtain the water depth h j , where j is an integer from 1 to M, and M is the number of nodes; (3) Deployment of wave measurement equipment Deploy N wave measurement devices around the target sea area, among which at least one device can give the main wave direction D of the wave. m , all wave measurement equipment can give the wave energy spectrum S i (f), where f is the frequency and i is an integer from 1 to N corresponding to the corresponding wave measurement equipment; (4) Measured wave element reception All wave measurement devices are turned on and start measuring at the same time, and send the measurement results to nearby receiving devices at the same time; (5) Measured data analysis According to the main wave direction D m Select the wave measurement data at the corresponding position as the boundary condition of the wave numerical model. For example, when the main wave is D m When the direction is east, the measurement data of the wave measurement equipment on the east side of the target sea area is selected as the boundary condition. Let the number of the equipment be t, and the corresponding wave energy spectrum be S t (f) According to S t (f) Calculate the average zero-crossing period Youyi Bogao (6) Selection of wave numerical model According to T z and h j Calculate the wave number k for each node zj Where g is the acceleration due to gravity, calculate k zj h j , when more than 30% of all nodes have k zj h j When <1, the wave numerical model uses the Boussinesq model, otherwise the gentle slope equation model is used; (7) Numerical simulation of wave evolution S t (f) applying to the incident wave boundary corresponding to the wave numerical model in step (5) to carry out numerical simulation; (8) Analysis of numerical results According to the simulation results, the energy spectrum S at each node is obtained using the spectrum analysis method. j (f) Calculate the corresponding average zero-crossing period and significant wave height; use the upper zero-crossing algorithm to obtain the maximum wave height and the period corresponding to the maximum wave height of each node, and complete the three-dimensional reconstruction of the wave; (9) Obtain the measured wave parameters at the next moment and repeat steps (5) to (7) until the task is completed.

2. The method for reconstructing a three-dimensional wave field of a typical sea area according to claim 1, characterized in that: In step (1), the scale of the target sea area terrain data must not be greater than 1:2000.

3. The method for reconstructing a three-dimensional wave field of a typical sea area according to claim 2, characterized in that: The wave measurement equipment described in step (3) includes a buoy and an acoustic Doppler current profiler ADCP.

4. The method for reconstructing a three-dimensional wave field of a typical sea area according to claim 1, characterized in that: The deployment of the wave measuring equipment in step (3) is as follows: when there are no islands, reefs or coastlines around, the number N of wave measuring equipment is not less than 4 sets, and they are evenly deployed in the four directions of the target sea area; when there are islands, reefs or coastlines around, no wave measuring equipment is deployed near the islands, reefs or coastlines, and multiple sets of wave measuring equipment are deployed at the other end away from the islands, reefs or coastlines.

5. The method for reconstructing a three-dimensional wave field of a typical sea area according to claim 1, characterized in that: In step (7), the effective physical duration of the simulation is required to be no less than half an hour.

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