Sea area hydrodynamic force and conservative substance migration prediction method
Through the hierarchical method and data decomposition technology under the σ coordinate system, the problems of vertical migration differences and insufficient analysis of dynamic mechanisms in the existing technology are solved, the refined prediction of marine hydrodynamics and conservative material migration is achieved, and the prediction accuracy is improved.
Patent Information
- Application Number
- CN202510802760.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-16
- Publication Date
- 2025-09-26
AI Technical Summary
Existing technologies cannot effectively reveal the migration differences among vertical layers, the prediction accuracy is insufficient, and there is a lack of quantitative analysis of the Euler residual current, Stokes residual current and tidal pump effect within the tidal cycle, making it difficult to adapt to the refined prediction needs of complex sea areas.
A hierarchical method in the σ coordinate system is adopted to collect data through the multi-parameter observation module and the simulation prediction module. The single-width net water flux and single-width net salt flux are calculated and decomposed into Euler terms, Stokes terms and tidal pump terms. Combined with the prediction analysis module, the differences in the migration mechanisms of each vertical layer of the water body are reflected.
It has achieved refined predictions of water and salt migration, improved prediction accuracy, clarified the contributions of different dynamic mechanisms, and adapted to the refined prediction needs of complex sea areas.
Smart Images
Figure CN120706303A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of marine engineering technology, and in particular to the prediction of marine hydrodynamics and conservative material migration. Background Art
[0002] The hydrodynamic characteristics of the sea area and the migration mechanism of conservative substances (such as salt and hazardous chemicals) are crucial to marine engineering safety and environmental protection. In existing technologies, migration prediction is usually based on a simplified model of vertical average, ignoring vertical layer changes. By solving the shallow water equations of vertical average flow velocity and water level evolution, as well as the advection-diffusion equation of vertical average substance concentration, the hydrodynamic characteristics of the sea area and the migration evolution of conservative substances are predicted, and the three-dimensional migration problem is projected onto a horizontal two-dimensional plane for efficient calculation.
[0003] However, existing prediction methods cannot reveal the migration differences between vertical layers, the prediction accuracy is low, and the migration mechanism of net water flux and salt flux is not clearly analyzed, resulting in insufficient prediction accuracy. At the same time, existing technologies usually rely on single observational data or simulation data for prediction, lacking quantitative analysis of Euler residual current, Stokes residual current and tidal pump effect within the tidal cycle, and are difficult to adapt to the refined prediction needs of complex sea areas.
[0004] Therefore, how to effectively improve prediction accuracy, analyze the flux mechanism, and achieve refined prediction of marine hydrodynamics and conservative material migration has become an urgent problem to be solved in this field. Summary of the Invention
[0005] In view of the defects of the prior art, the purpose of the present invention is to provide a method for predicting sea hydrodynamics and conservative material migration with high prediction accuracy.
[0006] In order to achieve the above-mentioned objectives, the present invention provides a method for predicting marine hydrodynamics and conservative material transport, comprising:
[0007] The vertical distribution data of total water depth, water velocity and salinity are collected through simulation prediction modules or multi-parameter observation modules distributed in the sea area.
[0008] The transport calculation module is based on the vertical stratification of water bodies in the σ coordinate system. It calculates the net water flux per unit width and the net salt flux per unit width according to the vertical distribution data of water flow velocity and salinity, and decomposes the flux mechanism of the net water flux per unit width and the net salt flux per unit width to obtain the Euler term, Stokes term and tidal pump term corresponding to water and salt transport.
[0009] The prediction and analysis module analyzes the differences in the migration mechanisms of vertical water layers based on the Euler term, Stokes term and tidal pump term of water and salt transport to obtain water and salt transport prediction results.
[0010] Furthermore, the simulation prediction module or the multi-parameter observation module divides the water body into σ layers based on the σ coordinate system, and the migration calculation module determines the upper and lower boundary positions of each layer and calculates the ratio of each layer to the total water depth to calculate the thickness of each layer.
[0011] Furthermore, the transport calculation module calculates the integral of the thickness of each layer and the velocity vector of each layer's single-width section during the tidal cycle, and obtains the single-width net water flux through tidal cycle time averaging.
[0012] Furthermore, the transport calculation module performs flux mechanism decomposition on the thickness of each layer and the velocity vector of each single-width section, decomposing the thickness of each layer into the tidal cycle average term of the thickness and the tidal cycle pulsation term of the thickness, and decomposing the velocity vector of each single-width section into the tidal cycle average term of the velocity vector and the tidal cycle pulsation term of the velocity vector.
[0013] Furthermore, the transport calculation module decomposes the single-width net water flux based on the thickness of each layer after flux mechanism decomposition and the flow velocity vector of each single-width section to obtain the Euler term and Stokes term of the water body.
[0014] Furthermore, the transport calculation module calculates the thickness of each layer within the tidal cycle, the velocity vector of each layer's single-width section, and the integral of the salinity of each layer, and obtains the net salt flux per width after averaging over the tidal cycle time.
[0015] Furthermore, the transport calculation module decomposes the flux mechanism of the salinity of each layer into the tidal cycle average term of salinity and the tidal cycle pulsation term of salinity.
[0016] Furthermore, the transport calculation module decomposes the single-width net salt flux based on the thickness of each layer after flux mechanism decomposition, the velocity vector of each single-width section and the salinity of each layer to obtain the Euler term and Stokes term of salt and the tidal pump term of water and salt.
[0017] Furthermore, the prediction and analysis module outputs the Euler term, Stokes term, and tidal pump term of water and salt transport as a migration mechanism difference map for each vertical layer of the water body.
[0018] The method for predicting marine hydrodynamics and conservative material transport provided by the present invention adopts a stratification method under the σ coordinate system, is compatible with observation data and simulation data, calculates the migration of water and salt, realizes the refinement of vertical stratification of water bodies, effectively reflects the migration differences of each layer of water bodies, and decomposes the single-width net water flux and single-width net salt flux into Euler terms, Stokes terms and tidal pump terms to clarify the contributions of different dynamic mechanisms and improve the accuracy of hydrodynamics and conservative material transport predictions. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention is further described below with reference to the accompanying drawings and specific embodiments.
[0020] Figure 1 A system block diagram of the marine hydrodynamic and conservative material transport prediction method;
[0021] Figure 2 Schematic diagram of a measuring station in an embodiment of the present invention.
[0022] Figure 3 Schematic diagram of the change of flow velocity and salinity over time at a measuring station during spring tide and neap tide in an embodiment of the present invention;
[0023] Figure 4 Schematic diagram of the decomposition value of the net salt flux per width during spring tide in an embodiment of the present invention;
[0024] Figure 5 Schematic diagram of the decomposition value of the net salt flux per width during low tide in an embodiment of the present invention. DETAILED DESCRIPTION
[0025] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below with reference to specific illustrations.
[0026] See also Figure 1 , which shows an example of the method for predicting sea hydrodynamics and conservative material transport provided by the present invention.
[0027] As can be seen from the figure, the migration prediction method of this example mainly uses the prediction module or multi-parameter observation module to collect vertical distribution data of total water depth, water flow velocity and salinity. The single-width net water flux and single-width net salt flux are calculated through the migration calculation module and decomposed into corresponding Euler terms, Stokes terms and tidal pump terms. The prediction and analysis module can analyze the differences in the migration mechanisms of each vertical layer of the water body to obtain water and salt migration prediction results. It is compatible with observation data and simulation data, effectively improving the prediction accuracy.
[0028] Specifically, the multi-parameter observation module is composed of existing monitoring equipment, such as ADCP current meters and CTD temperature, salinity and depth sensors, and is deployed in the sea area to collect vertical distribution data of total water depth D, water flow velocity and salinity, and reflect the vertical stratification of water bodies in the σ coordinate system to obtain observation data.
[0029] Furthermore, the simulation and prediction module is composed of existing hydrodynamic simulation models, such as a three-dimensional ocean numerical model, which simulates the hydrodynamics of the sea area and can simulate the vertical distribution data of the total water depth D, water flow velocity and salinity, while reflecting the vertical stratification of the water body under the σ coordinate system to obtain simulation data.
[0030] The vertical distribution data of water velocity include velocity vector of each layer single width section The vertical distribution data of salinity include the salinity S of each layer. The water body is vertically divided into σ layers in the σ coordinate system. For example, in the observed data, the water body is vertically divided into 6 layers in the σ coordinate system, while in the simulated data, the water body is vertically divided into 10 layers in the σ coordinate system.
[0031] Here, the vertical stratification of water bodies in the σ coordinate system is a conventional technical means in this field and will not be described in detail here.
[0032] In this way, the migration calculation module collects and processes observation data and simulation data respectively through a unified data interface, and can use observation data or simulation data to predict the migration of water and salt to achieve compatibility of observation data or simulation data.
[0033] Specifically, the migration calculation module first calculates the thickness of each layer based on the total water depth D and the vertical stratification of the water body in the σ coordinate system.
[0034] As an example, the water body is divided into σ layers vertically in the σ coordinate system. The upper and lower boundaries of each layer are defined as σ1 and σ2, respectively. The ratio Δσ of each layer relative to the total water depth D can be obtained based on the upper and lower boundary positions, Δσ = σ1 - σ2. Therefore, the thickness H of each layer is H = ΔσD.
[0035] Furthermore, the transport calculation module calculates the thickness H of each layer and the velocity vector of each layer's single width section within the tidal cycle T. The net water flux per unit width is obtained by integrating the tidal cycle time average
[0036] Specifically:
[0037] Then, the transport calculation module splits the single-width net water flux into the tidal cycle average term and the tidal cycle pulsation term based on the turbulence analysis method of fluid mechanics, and calculates the flow velocity vector of each layer thickness H and each layer single width section. The flux mechanism is decomposed into:
[0038] in, is the tidal cycle average term of thickness, and H' is the tidal cycle pulsation term of thickness; is the tidal cycle average term of the velocity vector, is the tidal period fluctuation term of the velocity vector.
[0039] Furthermore, the transport calculation module decomposes the single-width net water flux into Euler terms and Stokes terms based on the tidal residual flow theory, the mass conservation equation and the momentum equation. The Euler term represents the horizontal transport caused by the tidal mean flow, and the Stokes term is the second-order residual flow generated by the water level-velocity phase difference within the tidal cycle.
[0040] Therefore, based on the thickness H of each layer after flux mechanism decomposition and the velocity vector of each layer single width section Single width water purification flux Decompose and obtain the Euler term and Stokes term of the water body, specifically:
[0041]
[0042] From this we can get:
[0043] Where, is the Euler term of the water body, which represents the transport of the water body by the Euler residual flow; is the Stokes term of the water body, which represents the transport of the water body by the Stokes residual current. The Euler term and Stokes term of the water body are obtained from this, thereby quantifying the contribution of different dynamic mechanisms to the single-width net water flux and revealing the differences in vertical stratified transport.
[0044] Similarly, the transport calculation module calculates the thickness H of each layer and the velocity vector of each layer's single width section within the tidal period T. The integral of the salinity S of each layer is averaged over the tidal cycle to obtain the net salt flux per width.
[0045] Specifically:
[0046] Next, the transport calculation module, based on the turbulence analysis method of fluid mechanics, splits the single-width net salt flux into the tidal cycle average term and the tidal cycle pulsation term, and decomposes the flux mechanism of the salinity S of each layer into: in, is the tidal cycle average term of salinity, and S` is the tidal cycle pulsation term of salinity, which are used to analyze the vertical stratification mechanism of salinity, such as saltwater intrusion.
[0047] Furthermore, the transport calculation module decomposes the single-width net salt flux into Euler term, Stokes term and tidal pump term based on the tidal residual flow theory, the mass conservation equation and the momentum equation. The Euler term represents the horizontal transport caused by the tidal mean flow, the Stokes term is the second-order residual flow caused by the velocity-salinity phase difference within the tidal cycle, and the tidal pump term is the nonlinear coupling of velocity-salinity pulsation within the tidal cycle.
[0048] Therefore, based on the thickness H of each layer after flux mechanism decomposition, the velocity vector of each layer single width section The net salt flux per unit width is affected by the salinity S of each layer Decomposition is performed to obtain the Euler term for salinity, the Stokes term, and the tidal pumping term for the water column and salinity.
[0049] Specifically:
[0050] Where, is the Euler term of salt, which represents the transport of salt by the Euler residual current; is the Stokes term of salt, which represents the transport of salt by the Stokes residual current; are the tidal pump terms of water and salinity, respectively representing the transport of salt by the tidal fluctuation term of water and salinity, and the transport of salinity by the tidal fluctuation term of water, thereby quantifying the contribution of different dynamic mechanisms to the single-width net salt flux and revealing the differences in vertical stratified transport.
[0051] Therefore, the transport calculation module can calculate the Euler term, Stokes term and tidal pump term corresponding to the vertical layers of water bodies in the σ coordinate system based on observation data or simulation data.
[0052] In conjunction with this, the prediction and analysis module is configured to analyze the differences in the migration mechanisms of each vertical layer of the water body based on the Euler term, Stokes term and tidal pump term of water and salt migration, and output it as a migration mechanism difference map of each vertical layer of the water body, so that the water and salt migration prediction results can be predicted based on the migration mechanism difference map of each vertical layer of the water body.
[0053] Here, the output of the prediction and analysis module is a diagram showing the difference in migration mechanisms of each vertical layer of the water body, which is a conventional technical means in this field and will not be elaborated here.
[0054] The following examples illustrate the working process of the present invention in a specific application. It should be noted that the content described here is only a specific application example of this solution and does not constitute a limitation to this solution.
[0055] Combine Figure 2 Taking the four monitoring stations A1, B1, C1, and D1 in the northern branch of the offshore area as an example, multi-parameter monitoring modules are deployed in the corresponding sea areas to collect the total water depth D, the velocity vector of each layer single width section, and the velocity of the water depth D, ... and the salinity S of each layer. At the same time, the water body is divided into 10 layers vertically in the σ coordinate system, and the profile data of each layer are drawn as follows Figure 3 shown.
[0056] Combine Figure 3 , which shows the velocity vectors of single-width sections at each layer at the 4 stations A1, B1, C1, and D1 during spring tide (left column) and neap tide (right column). The salinity S of each layer changes with time. For the velocity vector, the negative sign indicates a rising tide and the positive sign indicates a falling tide.
[0057] Furthermore, the migration calculation module uses observation data to calculate the velocity vector of each layer according to the single-width section. The net water flux per width and the net salt flux per width are calculated based on the salinity S of each layer, and the flux mechanism of the net water flux per width and the net salt flux per width is decomposed to obtain the Euler term, Stokes term and tidal pump term corresponding to the water body and salt transport. The prediction and analysis module outputs the migration mechanism difference map of each vertical layer of the water body based on the Euler term, Stokes term and tidal pump term of the water body and salt transport, as shown in Figure 2. Figure 4 and Figure 5 shown.
[0058] Combine Figure 4 , which shows the net salt flux per unit width of the surface layer (left column) and bottom layer (right column) at each station in the North Branch during spring tide, as well as the Euler term, Stokes term and tidal pump term of salt transport. Among them, Figure (4a) and Figure (4b) represent the net salt flux per unit width of the surface layer and bottom layer, respectively; Figure (4c) and Figure (4d) represent the Euler term of salt in the surface layer and bottom layer, respectively; Figure (4e) and Figure (4f) represent the Stokes term of salt in the surface layer and bottom layer, respectively; Figure (4g) and Figure (4h) represent the tidal pump term of salt in the surface layer and bottom layer, respectively.
[0059] Therefore, according to Figure 4 It can be seen that during spring tides, the net salt flux per unit width of the surface and bottom layers of the North Branch migrates from sea to land, with the intensity of this transport being weaker in the upper section than in the middle and lower sections, with greater intensity at the surface layer at the mouth and less at the bottom layer. Controlled by the downward flow of runoff, Eulerian transport of surface and bottom layers in the North Branch is from land to sea. However, due to the stronger tidal forces during spring tides, the direction of Stokes and tidal pump transport in the North Branch is clearly from sea to land, with Stokes transport being stronger and tidal pump transport being weaker. Under the combined influence of Stokes and tidal pump transport, the overall salt transport in the North Branch during spring tides is from sea to land, which promotes the reverse intrusion of salt water from the offshore waters of the North Branch during spring tides.
[0060] Therefore, the consistent landward orientation of Stokes transport during spring tides in the North Branch is a significant source of salt transport in the North Branch. Tidal pumping is also a significant source of salt transport in the North Branch. This suggests that tidal pumping and Stokes transport are the primary sources of salt transport in the North Branch during spring tides.
[0061] Further, combined with Figure 5 , which shows the net salt flux per unit width of the surface layer (left column) and bottom layer (right column) at each station in the northern branch during low tide, as well as the Euler term, Stokes term and tidal pump term of salt transport. Among them, Figure (5a) and Figure (5b) represent the net salt flux per unit width of the surface layer and bottom layer, respectively; Figure (5c) and Figure (5d) represent the Euler term of salt in the surface layer and bottom layer, respectively; Figure (5e) and Figure (5f) represent the Stokes term of salt in the surface layer and bottom layer, respectively; Figure (5g) and Figure (5h) represent the tidal pump term of salt in the surface layer and bottom layer, respectively.
[0062] according to Figure 5As can be seen, during neap tides, the net salt flux per unit width of the surface and bottom layers of the North Branch migrates in a direction significantly opposite to that of spring tides, moving from land to sea. The intensity of this migration is weaker in the upper section of the North Branch than in the middle and lower sections, and greater in the surface layer than in the bottom layer. Because tidal forces are significantly weaker during neap tides than during spring tides, runoff dominates, significantly reducing the intensity of Stokes and tidal pumping transport. Controlled by the downward flow of runoff, the overall salt migration in the North Branch is from land to sea, driven by Eulerian transport. Therefore, saltwater backflow in the North Branch occurs only during spring tides under normal winds and disappears during neap tides.
[0063] Thus, the water and salt transport prediction results are obtained.
[0064] The method for predicting marine hydrodynamics and conservative material transport provided by the present invention adopts a stratification method under the σ coordinate system, is compatible with observation data and simulation data, calculates the migration of water and salt, realizes the refinement of vertical stratification of water bodies, effectively reflects the migration differences of each layer of water bodies, and decomposes the single-width net water flux and single-width net salt flux into Euler terms, Stokes terms and tidal pump terms to clarify the contributions of different dynamic mechanisms and improve the accuracy of hydrodynamics and conservative material transport predictions.
[0065] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for predicting marine hydrodynamics and conservative material transport, characterized in that: include: The vertical distribution data of total water depth, water velocity and salinity are collected through simulation prediction modules or multi-parameter observation modules distributed in the sea area. The transport calculation module is based on the vertical stratification of water bodies in the σ coordinate system. It calculates the net water flux per unit width and the net salt flux per unit width according to the vertical distribution data of water flow velocity and salinity, and decomposes the flux mechanism of the net water flux per unit width and the net salt flux per unit width to obtain the Euler term, Stokes term and tidal pump term corresponding to water and salt transport. The prediction and analysis module analyzes the differences in the migration mechanisms of vertical water layers based on the Euler term, Stokes term and tidal pump term of water and salt transport to obtain water and salt transport prediction results.
2. The method for predicting sea area hydrodynamics and conservative material transport according to claim 1, characterized in that: The simulation prediction module or the multi-parameter observation module divides the water body into σ layers based on the σ coordinate system. The migration calculation module determines the upper and lower boundary positions of each layer and calculates the ratio of each layer to the total water depth to calculate the thickness of each layer.
3. The method for predicting sea area hydrodynamics and conservative material transport according to claim 2, characterized in that: The transport calculation module calculates the integral of the thickness of each layer and the velocity vector of each layer's single-width section during the tidal cycle, and obtains the single-width net water flux by averaging the tidal cycle time.
4. The method for predicting sea area hydrodynamics and conservative material transport according to claim 3, characterized in that: The transport calculation module performs flux mechanism decomposition on the thickness of each layer and the velocity vector of each single-width section, decomposing the thickness of each layer into the tidal cycle average term of the thickness and the tidal cycle pulsation term of the thickness, and decomposing the velocity vector of each single-width section into the tidal cycle average term of the velocity vector and the tidal cycle pulsation term of the velocity vector.
5. The method for predicting sea area hydrodynamics and conservative material transport according to claim 4, characterized in that: The transport calculation module decomposes the single-width net water flux based on the thickness of each layer after flux mechanism decomposition and the velocity vector of each single-width section to obtain the Euler term and Stokes term of the water body.
6. The method for predicting sea area hydrodynamics and conservative material transport according to claim 5, characterized in that: The transport calculation module calculates the thickness of each layer, the velocity vector of each layer's single-width section, and the integral of each layer's salinity during the tidal cycle, and obtains the net salt flux per width by averaging the tidal cycle time.
7. The method for predicting sea area hydrodynamics and conservative material transport according to claim 6, characterized in that: The transport calculation module decomposes the flux mechanism of the salinity of each layer into the tidal cycle average term of salinity and the tidal cycle pulse term of salinity.
8. The method for predicting sea area hydrodynamics and conservative material transport according to claim 7, characterized in that: The transport calculation module decomposes the single-width net salt flux based on the thickness of each layer after flux mechanism decomposition, the velocity vector of each single-width section and the salinity of each layer to obtain the Euler term, Stokes term of salt and the tidal pump term of water body and salt.
9. The method for predicting sea area hydrodynamics and conservative material transport according to claim 8, characterized in that: The prediction and analysis module outputs the Euler term, Stokes term and tidal pump term of water and salt transport as a migration mechanism difference map of each vertical layer of the water body.