Density Stratification Flow Velocity Correction Method and System Based on Linear Multilayer Non-Hydrostatic Theory

Abstract

The present invention discloses a density stratification flow velocity correction method and system based on the linear multi-layer non-hydrostatic theory, including: obtaining the seawater density distribution and water level change distribution of a target sea area, and calculating the dimensionless density profile of seawater based on the seawater density distribution; stratifying the target sea area longitudinally to obtain a number of seawater layers, and calculating the dimensionless density and dimensionless thickness corresponding to each seawater layer based on the dimensionless density profile of seawater; calculating the flow velocity attenuation coefficient based on the total number of seawater layers, dimensionless density and dimensionless thickness; performing a spatial Fourier transform on the water level change distribution to obtain the wave number domain distribution of the water level change; calculating the wave velocities at different wave numbers based on the wave number domain distribution according to the linear wave theory; correcting the wave velocities based on the flow velocity attenuation coefficient, and outputting the corrected wave velocities.

Description

Technical Field

[0001] The present invention belongs to the field of ocean wave velocity evaluation and correction, and particularly relates to a density-stratified flow velocity correction method and system based on the linear multi-layer non-hydrostatic theory. Background Art

[0002] Ocean waves are of great significance for ocean engineering, weather forecasting, ocean ecological protection, etc.: In ocean engineering, such as in the fields of offshore wind power, port construction, and ocean resource development, accurate prediction of ocean waves is a prerequisite for designing safe and reliable engineering structures; when conducting ocean weather forecasting, it often relies on ocean waves to evaluate the dynamic changes of the ocean, enhance the timeliness and accuracy of forecasting, and provide more reliable meteorological services for society; ocean waves not only affect the transfer of heat and momentum, but also have a direct impact on the habitat environment of marine organisms. Ocean waves are manifested as wave velocities, which is a complex phenomenon involving multiple levels and multiple factors interacting with each other, and involves multiple fields such as fluid dynamics, thermodynamics, and environmental science.

[0003] With the intensification of climate change, ocean pollution, and the impact of human activities on the ocean ecosystem, it has become increasingly important to accurately predict and understand the behavior of ocean waves. In this context, researchers have been continuously exploring more accurate wave models to improve the prediction ability of ocean waves. However, traditional wave models often assume hydrostatic pressure or homogeneous media, making it difficult to reflect the complex situations in the ocean, such as density stratification caused by temperature and salinity changes, flow non-uniformity, etc., resulting in poor prediction accuracy of wave velocities.

[0004] Therefore, how to provide a density-stratified flow velocity correction method based on linear multi-layer non-hydrostatic pressure to improve the prediction accuracy of wave velocities has become an urgent technical problem to be solved. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a density-stratified flow velocity correction method and system based on the linear multi-layer non-hydrostatic theory.

[0006] In the first aspect, an embodiment of the present invention provides a density-stratified flow velocity correction method based on the linear multi-layer non-hydrostatic theory, and the method includes the following steps:

[0007] Obtain the seawater density distribution and water level change distribution of the target sea area, and calculate the dimensionless density profile of seawater based on the seawater density distribution;

[0008] Stratify the target sea area longitudinally to obtain several seawater layers, and calculate the dimensionless density and dimensionless thickness corresponding to each seawater layer based on the dimensionless density profile of seawater;

[0009] Calculate the flow velocity attenuation coefficient based on the total number of seawater layers, dimensionless density, and dimensionless thickness;

[0010] Perform a spatial Fourier transform on the water level change distribution to obtain the wave number domain distribution of the water level change; based on the linear wave theory, calculate the wave velocities at different wave numbers according to the wave number domain distribution;

[0011] Correct the wave velocity based on the flow velocity attenuation coefficient and output the corrected wave velocity.

[0012] In a second aspect, an embodiment of the present invention provides a density-stratified flow velocity correction system based on the linear multi-layer non-hydrostatic theory to implement the above-mentioned density-stratified flow velocity correction method based on the linear multi-layer non-hydrostatic theory. The system includes:

[0013] A seawater data acquisition module, configured to acquire the seawater density distribution and water level change distribution of the target sea area, and calculate the dimensionless density profile of seawater based on the seawater density distribution;

[0014] A seawater stratification module, configured to stratify the target sea area longitudinally to obtain a number of seawater layers, and calculate the corresponding dimensionless density and dimensionless thickness of each seawater layer based on the dimensionless density profile of seawater;

[0015] A flow velocity attenuation coefficient calculation module, configured to calculate the flow velocity attenuation coefficient based on the total number of seawater layers, dimensionless density, and dimensionless thickness;

[0016] A wave velocity calculation module, configured to perform a spatial Fourier transform on the water level change distribution to obtain the wave number domain distribution of the water level change; based on the linear wave theory, calculate the wave velocities at different wave numbers according to the wave number domain distribution;

[0017] A wave velocity correction module, configured to correct the wave velocity based on the flow velocity attenuation coefficient and output the corrected wave velocity.

[0018] In a third aspect, an embodiment of the present invention provides an electronic device, including a memory and a processor, the memory is coupled to the processor; wherein, the memory is used to store program data, and the processor is used to execute the program data to implement the above-mentioned density-stratified flow velocity correction method based on the linear multi-layer non-hydrostatic theory.

[0019] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the above-mentioned density-stratified flow velocity correction method based on the linear multi-layer non-hydrostatic theory.

[0020] Fifth aspect, an embodiment of the present invention provides a computer program product, including a computer program / instructions, which when executed by a processor implement the above-mentioned density-stratified flow velocity correction method based on the linear multi-layer non-hydrostatic theory.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The present invention provides a density-stratified flow velocity correction method based on the linear multi-layer non-hydrostatic theory, including: obtaining the sea water density distribution and water level change distribution of the target sea area, and calculating the dimensionless density profile of the sea water based on the sea water density distribution; stratifying the target sea area longitudinally to obtain several sea water layers, and calculating the dimensionless density and dimensionless thickness corresponding to each sea water layer based on the dimensionless density profile of the sea water; calculating the flow velocity attenuation coefficient based on the total number of sea water layers, dimensionless density and dimensionless thickness; performing a spatial Fourier transform on the water level change distribution to obtain the wave number domain distribution of the water level change; calculating the wave flow velocity at different wave numbers based on the linear wave theory according to the wave number domain distribution; correcting the wave flow velocity based on the flow velocity attenuation coefficient, and outputting the corrected wave flow velocity. The present invention respectively considers the motion characteristics and their interactions of each sea water layer to comprehensively capture the propagation characteristics and energy distribution of ocean waves, reveal the dynamic relationship between different sea water layers, correct the deficiencies of traditional wave models, calculate the wave flow velocity at different wave numbers based on the water level change distribution, and correct the wave flow velocity through the flow velocity attenuation coefficient, and can achieve arbitrary accuracy by continuously adding the number of sea water layers, improving the prediction accuracy of the wave flow velocity. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 is a flowchart of a density-stratified flow velocity correction method based on linear multi-layer non-hydrostatic pressure provided by an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of the dimensionless density profile of sea water provided by an embodiment of the present invention;

[0026] Figure 3 is a parameter schematic diagram of the dimensionless density profile of eight-layer sea water provided by an embodiment of the present invention;

[0027] Figure 4 is a schematic diagram of wave flow velocity correction provided by an embodiment of the present invention;

[0028] Figure 5 It is a schematic structural diagram of a density-stratified flow velocity correction system based on linear multi-layer non-hydrostatic pressure provided by an embodiment of the present invention;

[0029] Figure 6 It is a schematic diagram of an electronic device provided by an embodiment of the present invention. Specific embodiments

[0030] The present invention will be further described below in conjunction with embodiments. The description of the following embodiments is only for helping to understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0031] In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions appears to be contradictory or unable to be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by this application.

[0032] As Figure 1 shown, an embodiment of the present invention provides a density-stratified flow velocity correction method based on the linear multi-layer non-hydrostatic pressure theory. The method includes the following steps:

[0033] Step S1, obtain the sea water density distribution and water level change distribution of the target sea area, and calculate the dimensionless density profile of the sea water based on the sea water density distribution.

[0034] Among them, the process of calculating the dimensionless density profile of the sea water based on the sea water density distribution includes:

[0035] Dividing the sea water density distribution by a characteristic density value to obtain the dimensionless density profile of the sea water; wherein, the characteristic density value is the maximum value in the sea water density distribution or the bottom density value.

[0036] Step S2, stratify the target sea area longitudinally to obtain several sea water layers, and calculate the dimensionless density and dimensionless thickness corresponding to each sea water layer based on the dimensionless density profile of the sea water.

[0037] Further, the process of stratifying the target sea area longitudinally to obtain several sea water layers includes:

[0038] Set the number of sampling points, and stratify the target sea area longitudinally according to the number of sampling points, so that the total number of sea water layers is greater than twice the number of sampling points;

[0039] Or,

[0040] Set the total number of sea water layers according to the empirical formula, and the expression is as follows:

[0041]

[0042] Wherein, N represents the total number of seawater layers, represents the error magnitude, represents the dimensionless density value of the seabed, represents the dimensionless density value of the sea surface.

[0043] Step S3: Calculate the velocity decay coefficient based on the total number of seawater layers, dimensionless density, and dimensionless thickness.

[0044] Furthermore, the expression of the velocity decay coefficient is as follows:

[0045]

[0046] Wherein, represents the velocity decay coefficient, is the acceleration due to gravity, is the water depth, is the wave number, represents the dimensionless density value corresponding to the th layer of seawater layer, represents the dimensionless thickness value corresponding to the th layer of seawater layer,

[0047] Step S4: Perform a spatial Fourier transform on the water level change distribution to obtain the wave number domain distribution of the water level change; Based on the linear wave theory, calculate the wave velocity at different wave numbers according to the wave number domain distribution.

[0048] Specifically, assume that at the initial time t = 0, the sea surface change is η(x,0), perform a Fourier transform on this distribution in the spatial domain to obtain the wave number domain distribution of the water level change, and the expression is as follows:

[0049]

[0050] Wherein, represents the Fourier transform of η(x,0) in the wave number domain, i is the imaginary unit, k is the wave number;

[0051] Based on the linear wave theory, at t = 0, the fluctuation of the sea surface is as follows:

[0052]

[0053] In the formula, is the wave speed. In the linear wave theory, the expression of the wave speed is as follows:

[0054]

[0055] In the formula, is the acceleration due to gravity, is the water depth.

[0056] Step S5: Correct the wave velocity based on the flow velocity decay coefficient and output the corrected wave velocity.

[0057] Furthermore, the influence of density stratification is not considered in the linear wave theory, so the calculated wave speed is on the fast side. In this patent, by considering the stratification effect of seawater density, the wave speed c is corrected, so that the model can obtain more accurate results. The expression of the corrected wave velocity is as follows:

[0058]

[0059] In the formula, is the wave speed, represents the velocity decay coefficient, is the acceleration due to gravity, is the water depth, is the wave number.

[0060] Next, this example elaborates on the process of theoretical derivation of a density stratification flow velocity correction algorithm based on the linear multi-layer non-hydrostatic theory.

[0061] To facilitate the display of the detailed calculation process, this example assumes that the model is calculated in a two-dimensional space coordinate system. As Figure 2 shown, is the sea surface height, is the seabed depth, and it is defined that is the total water depth. In this example, the water flow is divided into water layers along the horizontal direction from the seabed to the sea surface, and the thickness of each water layer is defined as:

[0062]

[0063] Among them, the coefficient is the water layer thickness coefficient, and its value range is 0 - 1. represents the interface layer position between the th water layer and the th water layer, where the sea surface and the seabed can be regarded as special interface layers, that is:

[0064]

[0065] Therefore, the position of each interface layer can be calculated:

[0066]

[0067] It should be noted that when the lower bound of the summation symbol in formula (4) is greater than the upper bound, the summation term is regarded as 0. denotes the density of the th water layer, assumed to be a constant, denotes the density at the interface layer . The densities of the seabed and the sea surface are approximately , ; the densities at the remaining interface layers are approximately:

[0068]

[0069] Based on the non-hydrostatic free surface flow model, the continuity equation and the momentum equation are:

[0070]

[0071]

[0072]

[0073] The boundary conditions are:

[0074]

[0075]

[0076] where denotes the density, denote the velocities along the horizontal direction and the vertical direction respectively, denotes the time, is the sea surface change, is the gravitational acceleration, and are the vertical velocities of the sea surface and the seabed respectively, and are the horizontal velocities of the sea surface and the seabed respectively, is the pressure term, and its expression is:

[0077]

[0078] where is the characteristic density, taking a constant; is the non-hydrostatic pressure term. The pressure term takes the value of 0 at the sea surface and is .

[0079] Integrate equations (6)-(8) along each layer to . Substitute the density approximation formula (5), the boundary conditions (9)-(10), and the pressure decomposition formula (11), and after linear approximation and eliminating the non-linear terms, the following equations can be obtained:

[0080]

[0081]

[0082]

[0083] where ranges from 1 to , represents the horizontal and vertical velocities of the -th layer. represents the vertical velocity of the -th boundary layer, represents the horizontal and vertical velocities of the -th boundary layer. represents the non-hydrostatic pressure of the -th boundary layer and the -th boundary layer.

[0084] and represent the dimensionless density values of the -th and -th water layers, and their expressions are:

[0085]

[0086] represents the action coefficient of the hydrostatic pressure term of the -th water layer, and its expression is:

[0087]

[0088] At this time, the linearized boundary conditions are written as:

[0089]

[0090]

[0091] Equations (12)-(14) represent the motion in the -th water layer. Therefore, there are a total of equations. Next, in this example, the variable is transformed as follows:

[0092]

[0093] where represents the new variable after transformation. At this time, equation (13) can be rewritten as:

[0094]

[0095] Sum up equation (12) from the seabed to the th water layer, and substitute it into the new variable (15), then the expression for the vertical velocity of the interface layer can be obtained:

[0096]

[0097] where and are the expressions for and respectively:

[0098]

[0099]

[0100] In addition, when , according to (21) and the boundary condition (17), we can get:

[0101]

[0102] According to the gradient formula, the vertical velocity in the water layer is approximately estimated as the mean of the vertical velocities of its adjacent interface layers, that is:

[0103]

[0104] Sum up equation (14) from the th water layer to the sea surface, and substitute it into formula (25), then the expression for the non-hydrostatic pressure term of the interface layer can be obtained:

[0105]

[0106] According to formula (26), the following expression can be calculated:

[0107]

[0108] where is a coefficient, and its expression is:

[0109]

[0110] Substituting (27) into (20), the following expression can be obtained:

[0111]

[0112] where the coefficient The expression is:

[0113]

[0114] The coefficient are all combinations of the layer thickness coefficient and the layer density coefficient Once these two sets of parameters are determined, the coefficients can be directly given. There are a total of unknowns in equations (24) and (29). Next, calculate the wave speed. Based on the small-amplitude system, let:

[0115]

[0116]

[0117] where and represent and the amplitudes of respectively, represents the wave number, is the imaginary unit. Substituting (31) and (32) into (24) and (29), a linear system of equations about and can be obtained:

[0118]

[0119]

[0120] The coefficient matrix form of the linear system of equations composed of (33) and (34) is:

[0121]

[0122] If the system of equations is to have a non-zero solution, it is necessary to ensure that the determinant of matrix (35) takes the value of 0. Calculate the determinant of (35). Substitute First, factor out from the first column, and factor out from the remaining columns; then multiply the first row by and divide the first column by to obtain:

[0123]

[0124] If the value of formula (36) is 0, it can be deduced that:

[0125]

[0126] wherein, represents the cofactor of the element in the first row and first column of the matrix , and its form is:

[0127]

[0128] contains all the coefficients of the horizontal velocity terms in the momentum equation (29) , and it represents the pressure change suffered by the water body under the action of the sea surface wave. represents the cofactor of the element in the first row and the th column, and its form can be written as:

[0129]

[0130] In the formula, characterizes the interaction between the spatial gradient of the sea surface and the horizontal velocity , and it describes the volume transport generated by the action of gravity during the propagation of the wave.

[0131] wherein, represents the cofactor of the element in the th row and the th column. Therefore, the wave speed can be solved as:

[0132]

[0133] where the attenuation coefficient can be expressed as:

[0134]

[0135] Formula (41) gives the flow velocity attenuation coefficient under the condition of determining the number of layers N, which can be applied to the correction calculation of the flow velocity. However, how to determine the value of N still needs to be discussed. The following will give a method of approximate estimation.

[0136] When , the wave speed (40) can be written as:

[0137]

[0138] If it is assumed that each water layer is evenly divided, at this time

[0139]

[0140] At this time, calculate The case when it approaches infinity:

[0141]

[0142] If the water depth is mapped to between [0, 1], then (44) can be rewritten as:

[0143]

[0144] Formula (45) can calculate any continuous density change. Assuming the density changes linearly from the seabed to the sea surface, the flow velocity is:

[0145]

[0146] The flow velocity of discrete stratification is:

[0147]

[0148] If we want to ensure that the results of (46) and (47) are close, we can calculate through the relative error, and thus we can obtain:

[0149]

[0150] Among them, represents the error magnitude, usually taking 10 -3 . Formula (48) gives a simple estimation method that can quickly estimate the number of layers for different density profiles.

[0151] To demonstrate the calculation process, apply the above conclusion to the generation and propagation process of tsunami waves. In two-dimensional space Assume that the initial seabed topography is flat and the seabed deformation is:

[0152]

[0153] Among them, is the Heaviside function, is the rupture velocity, then the calculation formula for the sea surface is:

[0154]

[0155] Among them, is the attenuation coefficient (i.e., the correction coefficient) calculated by formula (41). is the Laplace transform operator, is the angular frequency.

[0156] To demonstrate the calculation process, the above conclusion can be applied to the generation and propagation process of simulated tsunami waves. In a two-dimensional space assuming the seabed deformation is:

[0157]

[0158] where represents the horizontal width of the seabed deformation, represents the Heavside function, and its formula is as follows:

[0159]

[0160] Then the sea surface at the initial moment is:

[0161]

[0162] Therefore, at the sea surface fluctuation is

[0163]

[0164] At this time, correct the in formula (47), set the sea surface density to 1020 kg / m 3 , and the seabed density to 1050 kg / m 3 . The density changes linearly from the seabed to the sea surface. In this example, take = 10 -3 . According to formula (48), when the number of seawater layers is greater than or equal to eight, it is sufficient to ensure that the error is less than the given requirement. Therefore, this example uses an eight-layer seawater layer model for demonstration. The density distribution is as Figure 3 shown. Set the horizontal width of the seabed deformation to be Figure 4 km, then the calculation results are as

[0165] shown. The dashed line is the result without density, and the solid line is the result with density. It can be found that the water level of the result with density is slightly higher and the propagation speed is slightly slower. Therefore, this method provides a fast flow velocity correction algorithm. Figure 5 On the other hand, as

[0166] shown, the present invention provides a density-stratified flow velocity correction system based on the linear multi-layer non-hydrostatic theory to implement the above density-stratified flow velocity correction method based on the linear multi-layer non-hydrostatic theory. The system includes:

[0167] A seawater data acquisition module for acquiring the seawater density distribution and water level change distribution in the target sea area, and calculating the dimensionless density profile of seawater based on the seawater density distribution;A seawater stratification module, which is used to stratify a target sea area longitudinally to obtain several seawater layers, and calculate the dimensionless density and dimensionless thickness corresponding to each seawater layer based on the dimensionless density profile of seawater;

[0168] A flow velocity attenuation coefficient calculation module, which is used to calculate the flow velocity attenuation coefficient based on the total number of seawater layers, dimensionless density, and dimensionless thickness of the seawater layer;

[0169] A wave flow velocity calculation module, which is used to perform a spatial Fourier transform on the water level change distribution to obtain the wave number domain distribution of the water level change; based on the linear wave theory, calculate the wave flow velocity at different wave numbers according to the wave number domain distribution;

[0170] A wave flow velocity correction module, which is used to correct the wave flow velocity based on the flow velocity attenuation coefficient and output the corrected wave flow velocity.

[0171] Regarding the system in the above embodiments, the specific ways in which each module performs operations have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0172] For the system embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to the descriptions in the method embodiments. The system embodiments described above are only illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this application. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0173] Correspondingly, the present application also provides an electronic device, including: one or more processors; a memory for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors implement the density stratification flow velocity correction method based on the linear multi-layer non-hydrostatic theory as described above. As Figure 6 shown, it is a hardware structure diagram of any device with data processing capabilities where the density stratification flow velocity correction method based on the linear multi-layer non-hydrostatic theory provided by the embodiment of the present invention is located. Except for Figure 6 the processors, memory, and network interfaces shown, any device with data processing capabilities where the device in the embodiment is located usually also includes other hardware according to the actual functions of the device with data processing capabilities, which will not be elaborated here.

[0174] Correspondingly, the present application further provides a computer-readable storage medium, on which computer instructions are stored. When the instructions are executed by a processor, the density stratification flow velocity correction method based on the linear multi-layer non-hydrostatic theory as described above is implemented. The computer-readable storage medium may be an internal storage unit of any device with data processing capabilities described in any of the foregoing embodiments, such as a hard disk or a memory. The computer-readable storage medium may also be an external storage device, such as a plug-in hard disk, a Smart Media Card (SMC), an SD card, a Flash Card, etc. equipped on the device. Further, the computer-readable storage medium may also include both an internal storage unit of any device with data processing capabilities and an external storage device. The computer-readable storage medium is used to store the computer program and other programs and data required by any device with data processing capabilities, and may also be used to temporarily store data that has been output or is to be output.

[0175] After considering the specification and practicing the content disclosed herein, those skilled in the art will readily conceive of other embodiments of the present application. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include known common knowledge or conventional technical means in the technical field not disclosed in the present application. The specification and embodiments are only regarded as exemplary.

[0176] It should be understood that the present application is not limited to the exact structure described above and shown in the drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A density stratified flow velocity correction method based on linear multilayer non-static pressure theory, characterized in that: The method comprises the following steps: Obtain the seawater density distribution and water level change distribution in the target sea area, and calculate the dimensionless density profile of seawater based on the seawater density distribution; The target sea area is layered longitudinally to obtain several seawater layers, and the dimensionless density and dimensionless thickness corresponding to each seawater layer are calculated based on the dimensionless density profile of seawater; The velocity attenuation coefficient is calculated based on the total number of seawater layers, dimensionless density, and dimensionless thickness; Perform spatial Fourier transform on the water level change distribution to obtain the wave number domain distribution of the water level change; based on the linear wave theory, calculate the wave velocity under different wave numbers according to the wave number domain distribution; The wave velocity is corrected based on the velocity attenuation coefficient and the corrected wave velocity is output.

2. The density stratified flow velocity correction method based on linear multilayer non-static pressure theory according to claim 1 is characterized in that: The process of calculating the dimensionless density profile of seawater based on the seawater density distribution includes: The dimensionless density profile of seawater is obtained by dividing the seawater density distribution by a characteristic density value; wherein the characteristic density value is the maximum value in the seawater density distribution or the seabed density value.

3. The density stratified flow velocity correction method based on linear multilayer non-static pressure theory according to claim 1 is characterized in that: The process of stratifying the target sea area longitudinally to obtain several seawater layers includes: Set the number of sampling points, and stratify the target sea area longitudinally according to the number of sampling points, so that the total number of seawater layers is greater than twice the number of sampling points; or, The total number of seawater layers is set according to the empirical formula, and the expression is as follows: ； Where N represents the total number of seawater layers. Indicates the size of the error, represents the dimensionless density of the seafloor, Represents the dimensionless density value of the sea surface.

4. The density stratified flow velocity correction method based on linear multilayer non-static pressure theory according to claim 1 is characterized in that: The process of calculating the velocity attenuation coefficient based on the total number of seawater layers, dimensionless density, and dimensionless thickness includes: ； In the formula, represents the velocity attenuation coefficient, For water depth, is the wave number, Indicates The dimensionless density value corresponding to the seawater layer, Indicates The dimensionless thickness value corresponding to the seawater layer, It represents the pressure change of water under the action of sea surface waves. Represents the volume transport caused by gravity during wave propagation.

5. The density stratified flow velocity correction method based on linear multilayer non-static pressure theory according to claim 1 is characterized in that: The water level change distribution is spatially Fourier transformed to obtain the wave number domain distribution of the water level change; based on the linear wave theory, the process of calculating the wave velocity under different wave numbers according to the wave number domain distribution includes: Assume that at the initial moment When , perform Fourier transform on the distribution in the spatial domain to obtain the wavenumber domain distribution of water level change, which is expressed as follows: ； In the formula, express The Fourier transform in the wavenumber domain is is an imaginary unit, is the wave number; Based on the linear wave theory, The sea surface fluctuations are as follows: ； In the formula, is the wave speed. In linear wave theory, the expression of wave speed is as follows: ； In the formula, is the acceleration due to gravity, For water depth.

6. A density stratified flow velocity correction method based on linear multilayer non-static pressure theory according to claim 1 or 4, characterized in that: The wave velocity is corrected based on the velocity attenuation coefficient to obtain the corrected wave velocity, which is expressed as follows: ； In the formula, is the wave speed, represents the velocity attenuation coefficient, is the acceleration due to gravity, For water depth, is the wave number.

7. A density stratified flow rate correction system based on linear multilayer non-static pressure theory, characterized in that: To implement the density stratified flow velocity correction method based on linear multilayer non-static pressure theory as described in any one of claims 1 to 6, the system comprises: The seawater data acquisition module is used to obtain the seawater density distribution and water level change distribution in the target sea area, and calculate the dimensionless density profile of seawater based on the seawater density distribution; The seawater stratification module is used to stratify the target sea area longitudinally to obtain several seawater layers, and calculate the dimensionless density and dimensionless thickness corresponding to each seawater layer based on the dimensionless density profile of seawater; A velocity attenuation coefficient calculation module, used to calculate the velocity attenuation coefficient based on the total number of seawater layers, dimensionless density and dimensionless thickness; The wave velocity calculation module is used to perform spatial Fourier transform on the water level change distribution to obtain the wave number domain distribution of the water level change; based on the linear wave theory, the wave velocity under different wave numbers is calculated according to the wave number domain distribution; The wave velocity correction module is used to correct the wave velocity based on the velocity attenuation coefficient and output the corrected wave velocity.

8. An electronic device, comprising a memory and a processor, characterized in that: The memory is coupled to the processor; wherein the memory is used to store program data, and the processor is used to execute the program data to implement the density stratified flow velocity correction method based on linear multilayer non-static pressure theory as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the density stratified flow velocity correction method based on the linear multilayer non-hydrostatic pressure theory as described in any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the density stratified flow velocity correction method based on the linear multilayer non-hydrostatic pressure theory described in any one of claims 1 to 6 is implemented.

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