Method and system for assessing the impact of an offshore wind farm on ocean waves

Abstract

The application discloses a kind of offshore wind farm to the evaluation method and system of marine wave influence, based on physical principle derivation inertia force caused first wave energy dissipation term, it is added in wave model, obtain improved wave model, obtain the parameter of the fan pile of offshore wind farm, it is input in improved wave model, wave field simulation is carried out to the sea area containing offshore wind farm, output first wave field simulation result, based on first wave field simulation result evaluation offshore wind farm to the influence of marine wave of sea area, by derivation inertia force caused first wave energy dissipation term, it is added in wave model, make wave model consider resistance and inertia force simultaneously, more truly and accurately reflect the interaction of fan large-diameter pile and wave, avoid the need for each fan pile to set extremely high resolution grid, improve the calculation efficiency, so as to more efficiently and accurately evaluate the influence of offshore wind farm to marine wave.

Description

Technical Field

[0001] This invention relates to the field of wind farm impact assessment technology, and in particular to a method and system for assessing the impact of offshore wind farms on ocean waves. Background Technology

[0002] With the large-scale development of offshore wind power, accurately assessing the impact of wind farms on the marine hydrodynamic environment has become crucial for engineering design and environmental assessment. Offshore wind farms affect the ocean in two ways: firstly, through their foundation structures or wind farm piles; and secondly, by reducing near-surface wind speeds in the wind farm area and wake region. Few studies investigate the impact of wind farm structures (piles) on waves through drag dissipation effects. For example, some wave models represent each individual pile foundation as a dry grid point (land), while others apply transmission coefficients. In general, previous studies simulating wind turbines as dry grid points in their models have two limitations: 1) the model resolution is too high to be applicable to large-scale offshore wind farm scenarios; 2) it can only represent diffraction effects, while wave forces, including drag and inertial forces, have not been accurately characterized. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method and system for assessing the impact of offshore wind farms on ocean waves, which can more efficiently and accurately assess the impact of offshore wind farms on ocean waves.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for assessing the impact of offshore wind farms on ocean waves, comprising: The energy dissipation term of the first wave caused by inertial force is derived based on physical principles; By adding the first wave energy dissipation term to the wave model, an improved wave model is obtained. Obtain the parameters of the wind turbine piles in an offshore wind farm; Input the parameters into the improved wave model, perform wave field simulation on the sea area containing the offshore wind farm, and output the first wave field simulation result; The impact of the offshore wind farm on ocean waves in the sea area is evaluated based on the simulation results of the first wave field, and the evaluation results are obtained.

[0005] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is as follows: An assessment system for the impact of offshore wind farms on ocean waves includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the various steps of the aforementioned assessment method for the impact of offshore wind farms on ocean waves.

[0006] The beneficial effects of this invention are as follows: Based on physical principles, the energy dissipation term of the first wave caused by inertial force is derived. This term is then added to the wave model to obtain an improved wave model. Parameters of the wind turbine piles of the offshore wind farm are obtained and input into the improved wave model. Wave field simulation is performed on the sea area containing the offshore wind farm, and the simulation results of the first wave field are output. Based on these simulation results, the impact of the offshore wind farm on ocean waves in the sea area is evaluated, yielding the evaluation results. This overcomes the limitations of the traditional "dry grid point" method or methods that only consider diffraction effects, by deriving the energy dissipation term of the first wave caused by inertial force. By incorporating the energy dissipation term into the wave model, the model can simultaneously consider drag and inertial forces, more realistically and accurately reflecting the interaction between the large-diameter wind turbine piles and waves. This improved wave model can then be directly used to simulate wave fields in sea areas containing offshore wind farms, thereby assessing the impact of offshore wind farms on ocean waves. This avoids the need for setting extremely high-resolution grids for each wind turbine pile, making wave simulation computationally possible for large-scale offshore wind farm areas, improving computational efficiency, and enabling a more efficient and accurate assessment of the impact of offshore wind farms on ocean waves. Attached Figure Description

[0007] Figure 1 This is a flowchart illustrating an embodiment of the present invention for assessing the impact of offshore wind farms on ocean waves; Figure 2 This is a schematic diagram of an assessment system for the impact of offshore wind farms on ocean waves, according to an embodiment of the present invention. Figure 3 This is a schematic diagram of wave field simulation in an assessment method for the impact of offshore wind farms on ocean waves according to an embodiment of the present invention. Figure 4 This is a schematic diagram comparing the wave inertial force and resistance experienced by cylinders of different diameters (simulating wind turbine piles and vegetation) in an assessment method for the impact of offshore wind farms on ocean waves, as described in an embodiment of the present invention. Detailed Implementation

[0008] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0009] Before detailing the embodiments of this application, some related concepts will first be explained: Wave energy dissipation term: A term describing the reduction of wave energy due to various physical mechanisms during wave propagation; Wave model: A mathematical model used to describe the motion of ocean waves; Wave field simulation: The process of numerically reproducing and analyzing the entire process of wave generation, propagation, deformation and interaction with topography (such as islands, reefs, coasts, bridges, etc.) in the ocean or water body using mathematical models and computer technology.

[0010] In existing technologies, wave models are directly used to assess the impact of offshore wind farms on ocean waves. The vegetation module in the wave model is designed to calculate the dissipation of wave energy by vegetation in shallow water, employing a cylindrical method. In this method, wave energy loss is calculated based on the actual work done by the vegetation cylinder on the fluid, expressed using the Morison equation. In the vegetation module, wave forces are derived from drag in the Morison equation, while inertial forces are neglected. This is because vegetation is assumed to be a small-diameter cylinder, and drag is considered the primary force, representing wave forces on a small-scale structure. However, for wind turbines, the diameter of the piles is typically large and cannot be ignored compared to the wavelength, representing wave forces on a large-scale structure; therefore, the influence of inertial forces must also be considered. Furthermore, the wave model represents each individual pile foundation as a dry grid point, leading to low computational efficiency.

[0011] To at least solve the above problems, please refer to Figure 1 This invention provides a method for assessing the impact of offshore wind farms on ocean waves, including: The energy dissipation term of the first wave caused by inertial force is derived based on physical principles; By adding the first wave energy dissipation term to the wave model, an improved wave model is obtained. Obtain the parameters of the wind turbine piles in an offshore wind farm; Input the parameters into the improved wave model, perform wave field simulation on the sea area containing the offshore wind farm, and output the first wave field simulation result; The impact of the offshore wind farm on ocean waves in the sea area is evaluated based on the simulation results of the first wave field, and the evaluation results are obtained.

[0012] As can be seen from the above description, the beneficial effects of the present invention are as follows: It overcomes the limitations of the traditional "dry grid point" method or only considering diffraction effects. By deriving the first wave energy dissipation term caused by inertial force and incorporating it into the wave model, the wave model can simultaneously consider drag and inertial force, more realistically and accurately reflecting the interaction between the large-diameter wind turbine piles and waves. After obtaining the improved wave model, the wave field simulation of the sea area containing offshore wind farms can be directly used to evaluate the impact of offshore wind farms on ocean waves. This avoids the need to set an extremely high resolution grid for each wind turbine pile, making wave simulation of large-scale offshore wind farm areas computationally possible, improving computational efficiency, and thus enabling a more efficient and accurate evaluation of the impact of offshore wind farms on ocean waves.

[0013] Furthermore, based on physical principles, the energy dissipation term of the first wave caused by inertial force is derived as follows: Based on the physical principle of energy consumption due to work done by inertial force and the interaction characteristics between wind turbine piles and fluid, an energy dissipation equation caused by inertial force is established based on the inertial force coefficient, fluid density, wind turbine pile volume, fluid horizontal velocity, wind turbine pile diameter, vertical distance from the seabed to the bottom of the wind turbine pile, and draft of the wind turbine pile. A dynamic pressure expression is established based on the continuity equation, momentum equation, seabed boundary conditions, and complex wave number of fluid mechanics. The dynamic pressure expression is simplified to obtain the simplified dynamic pressure expression; Based on the energy dissipation equation and the dynamic pressure expression, a statistical averaging process is performed to obtain the average energy dissipation expression under the random wave field. The expression for the average energy dissipation under the random wave field is simplified to obtain the first wave energy dissipation term caused by inertial force.

[0014] As described above, starting from the physical essence of work done by inertial force and combining the interaction characteristics between the wind turbine pile and the fluid, a dynamic pressure expression is constructed through the continuity equation, momentum equation and boundary conditions. After statistical averaging and simplification, the inertial force energy dissipation term under the random wave field is derived. This process not only ensures the physical rationality and theoretical rigor of the energy dissipation mechanism, but also avoids fine mesh modeling of a single pile. It can accurately characterize the inertial dissipation effect of the wind turbine pile on wave energy while maintaining computational efficiency.

[0015] Furthermore, based on the physical principle of energy consumption due to inertial force and the interaction characteristics between the wind turbine pile and the fluid, an energy dissipation equation caused by inertial force is established based on the inertial force coefficient, fluid density, wind turbine pile volume, fluid horizontal velocity, wind turbine pile diameter, vertical distance from the seabed to the bottom of the wind turbine pile, and draft of the wind turbine pile. Specifically: ; In the formula, This indicates energy dissipation caused by inertial forces. This indicates the vertical distance from the seabed to the bottom of the wind turbine pile. Indicates the draft of the wind turbine pile. Indicates water depth. Represents inertial force. Indicates the horizontal velocity of the fluid. Indicates the inertial force coefficient. Indicates fluid density, This indicates the volume of the wind turbine pile. Indicates the diameter of the wind turbine pile. Represents the spatial coordinates of the seawater in the vertical direction.

[0016] As described above, inertial force is the resistance force exerted by the wind turbine piles on the fluid when the fluid's motion changes (such as acceleration or deceleration). This resistance force consumes the kinetic energy of the waves, converting it into heat energy or other forms of energy (i.e., energy dissipation). Due to inertial force... Since it is related to acceleration, an energy dissipation equation caused by inertial force is established based on the inertial force coefficient, fluid density, wind turbine pile volume, fluid horizontal velocity, wind turbine pile diameter, vertical distance from the seabed to the bottom of the wind turbine pile, and draft of the wind turbine pile.

[0017] Furthermore, a dynamic pressure expression is established based on the continuity equation, momentum equation, seabed boundary conditions, and complex wave number of fluid mechanics, specifically as follows: ; ; ; In the formula, Indicates pressure. Represents gravitational acceleration. represents the wave height, Represents the complex wave number. Indicates the angular frequency of the wave. Indicates wave number, This represents the complex coefficients directly related to the complex wavenumber. Represents the imaginary unit. Represents the exponential decay coefficient. Indicates the horizontal distance along the direction of wave propagation. Indicates time, Represents the dimensionless damping coefficient; The dynamic pressure expression is simplified to obtain the simplified dynamic pressure expression, as follows: ; ; ; ; ; In the formula, This represents the dimensionless wave energy attenuation coefficient. Indicates the first intermediate parameter. This indicates the second intermediate parameter. This represents the drag coefficient.

[0018] As described above, since the fluid velocity and acceleration in the energy dissipation equation caused by inertial force cannot be directly obtained, and the coupling effect of wave propagation and attenuation is not considered, it is necessary to further associate key physical quantities through fluid dynamics equations. Therefore, a dynamic pressure expression is established based on the continuity equation, momentum equation, seabed boundary conditions, and complex wave number of fluid dynamics. However, in the actual ocean, wave propagation and energy attenuation occur simultaneously, and real parameters are difficult to take into account both effects. The complex wave number is introduced to make the derivation more in line with the actual wave motion law, and realize the synchronous characterization of the wave "propagation + attenuation" coupling characteristics. Furthermore, the dynamic pressure expression is simplified, which can reduce the computational complexity.

[0019] Furthermore, based on the energy dissipation equation and the dynamic pressure expression, a statistical averaging process is performed to obtain the average energy dissipation expression under the random wave field, specifically: ; In the formula, This represents the average energy dissipation under a random wave field. This represents the wavenumber corresponding to the period of the spectral peak. This represents the wave angular frequency corresponding to the period of the spectral peak. This represents the third intermediate parameter. This represents the fourth intermediate parameter. Indicates wave height The Rayleigh probability density function; The expression for the average energy dissipation under the random wave field is simplified to obtain the first wave energy dissipation term caused by inertial force, specifically: ; In the formula, This represents the total energy of the wave.

[0020] As described above, waves in the actual ocean are randomly distributed (with varying wave heights and periods), rather than ideal waves with a single fixed wave height. Based on the industry-consensus assumption that "wave height follows a Rayleigh distribution," the instantaneous energy dissipation is statistically averaged, and the intermediate coefficients and Rayleigh probability density function are integrated to obtain the average energy dissipation expression under a random wave field. After statistical averaging, the derived results are more consistent with engineering practice, avoiding simulation errors caused by a single wave height assumption and improving practicality. In addition, the total wave energy is a core basic parameter that is easily obtained in wave models. After converting the dissipation term into a function of the total wave energy, there is no need to input complex observation data. It can be directly embedded into the wave action balance equation of the model for collaborative calculation, balancing computational efficiency and engineering applicability, and achieving accurate simulation of wave fields under the influence of large-scale wind farms.

[0021] Furthermore, by incorporating the first wave energy dissipation term into the wave model, the improved wave model is obtained, which includes: The first wave energy dissipation term is added to the vegetation module of the wave model to obtain an improved wave model. The vegetation module includes a second wave energy dissipation term caused by resistance.

[0022] As described above, adding the first wave energy dissipation term to the vegetation module of the wave model, which includes the second wave energy dissipation term caused by resistance, allows for the calculation of wave energy dissipation to consider not only the resistance term but also the inertial force term caused by the large-diameter piles of the wind turbine, thus more accurately characterizing the dissipation effect of the wind turbine piles on wave energy.

[0023] Furthermore, the parameters include pile diameter, draft, resistance coefficient, and inertial force coefficient; The parameters are input into the improved wave model, and wave field simulation is performed on the sea area containing the offshore wind farm. The first wave field simulation result is output, including: The pile diameter, draft, drag coefficient, and inertial force coefficient are input into the improved wave model to simulate the wave field in the sea area containing the offshore wind farm, and the first wave field simulation result is output.

[0024] As described above, by inputting the pile diameter, draft, drag coefficient, and inertial force coefficient into the improved wave model, wave field simulation of the sea area containing offshore wind farms can be achieved quickly and accurately, realizing wave simulation of a large-scale offshore wind farm area.

[0025] Furthermore, it also includes: The wave model is used to simulate the wave field in the sea area, and the second wave field simulation result is output.

[0026] As described above, the original wave model is used to simulate the wave field of the sea area, and the second wave field simulation results are output, which facilitates subsequent comparison and evaluation of the impact of offshore wind farms on ocean waves.

[0027] Furthermore, based on the simulation results of the first wave field, the impact of the offshore wind farm on the ocean waves in the sea area is evaluated, and the evaluation results include: By comparing the simulation results of the first wave field and the simulation results of the second wave field, the influence of the offshore wind farm on the effective wave height, average wave direction and average wavelength of the ocean waves in the sea area is quantitatively evaluated, and the modulation degree and spatial distribution characteristics of the ocean waves by the offshore wind farm are obtained.

[0028] As can be seen from the above description, comparing the simulation results of the first wave field and the simulation results of the second wave field, the quantitative assessment of the impact of offshore wind farms on the effective wave height, average wave direction and average wavelength of ocean waves is more reliable and efficient, and has important practical significance for the planning, design and environmental impact assessment of offshore wind power.

[0029] Please refer to Figure 2 Another embodiment of the present invention provides an assessment system for the impact of offshore wind farms on ocean waves, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the various steps of the above-described assessment method for the impact of offshore wind farms on ocean waves.

[0030] The method and system for assessing the impact of offshore wind farms on ocean waves described above are applicable to scenarios involving the assessment of the impact of offshore wind farms on ocean waves. The following detailed implementation methods illustrate these methods: Please refer to Figure 1 One embodiment of the present invention is as follows: A method for assessing the impact of offshore wind farms on ocean waves, comprising: S1. Based on physical principles, derive the energy dissipation term of the first wave caused by inertial force, specifically including S11-S15: Inertial force is the resistance force exerted by the wind turbine piles on the fluid when the fluid's motion changes (such as acceleration or deceleration). This resistance force dissipates the kinetic energy of the waves, converting it into heat or other forms of energy (i.e., energy dissipation). Since it is related to acceleration, the resulting energy dissipation equation is as follows.

[0031] S11. Based on the physical principle of energy consumption due to work done by inertial force and the interaction characteristics between the wind turbine pile and the fluid, an energy dissipation equation caused by inertial force is established based on the inertial force coefficient, fluid density, wind turbine pile volume, fluid horizontal velocity, wind turbine pile diameter, vertical distance from the seabed to the bottom of the wind turbine pile, and draft of the wind turbine pile. Specifically: ; In the formula, This indicates energy dissipation caused by inertial forces. This indicates the vertical distance from the seabed to the bottom of the wind turbine pile. This indicates the water depth of the wind turbine piles. Indicates water depth. Represents inertial force. Indicates the horizontal velocity of the fluid. Indicates the inertial force coefficient. Indicates fluid density, This indicates the volume of the wind turbine pile. Indicates the diameter of the wind turbine pile. The coordinates represent the vertical spatial coordinates of the seawater (negative values ​​indicate below the sea surface). It is assumed here that the fluid convection acceleration and stress in this region are negligible.

[0032] Inertial force is the force generated by the wind turbine pile that hinders the acceleration or deceleration of fluid. The wave energy consumed by this force is equivalent to the negative work done on the fluid. Based on this, we introduce the horizontal cross-sectional area of ​​the pile (reflecting the range of interaction between the pile and the fluid), the horizontal velocity of the fluid (reflecting the basis of fluid kinetic energy), the horizontal acceleration of the fluid (reflecting the core source of the magnitude of the inertial force), and a vertical integral infinitesimal element (covering the full draft of the pile), and combine them to form an energy dissipation expression for the local infinitesimal element.

[0033] S12. Based on the continuity equation, momentum equation, seabed boundary conditions, and complex wave number of fluid mechanics, establish a dynamic pressure expression, specifically as follows: ; ; ; In the formula, Indicates pressure. Represents gravitational acceleration. represents the wave height, Represents the complex wave number. Indicates the angular frequency of the wave. Indicates wave number, These represent complex coefficients directly related to the complex wave number. Their core function is to jointly describe the wave propagation characteristics and energy attenuation effects in the vertical direction, serving entirely for the calculation of the vertical distribution of dynamic pressure. Represents the imaginary unit. Represents the exponential decay coefficient. Indicates the horizontal distance along the direction of wave propagation. Indicates time, This represents the dimensionless damping coefficient.

[0034] To obtain the fluid velocity and acceleration required for the previous equation, the expression for dynamic pressure is derived by combining the continuity equation, horizontal and vertical momentum equations of fluid mechanics, and introducing seabed boundary conditions. In actual oceans, wave propagation and energy attenuation occur simultaneously, and real parameters cannot account for both effects. Complex wave numbers are introduced to make the derivation more consistent with the actual wave motion, thus achieving a synchronous characterization of the wave "propagation + attenuation" coupling characteristics.

[0035] Wherein, the seabed boundary condition is (i.e., seabed) (That is, the vertical velocity is 0).

[0036] In the weak In this case, the previous equation is combined and The following can be used as an approximation, as follows.

[0037] S13. The dynamic pressure expression is simplified to obtain the simplified dynamic pressure expression, specifically: ; ; ; ; ; In the formula, This represents the dimensionless wave energy attenuation coefficient. Indicates the first intermediate parameter. This indicates the second intermediate parameter. This represents the drag coefficient.

[0038] The previous equation contains multiple complex trigonometric functions and complex variable combinations. Directly substituting them into the equation would be difficult and inefficient. Based on the actual scenario of offshore wind farms, the dissipation effect of the piles on waves is "weakly damped" (it will not cause the waves to disappear instantly). Based on this, a reasonable simplification is made: the complex wave number is simplified and approximated, and after substituting it into the previous equation, redundant and complex terms are eliminated to obtain a simplified dynamic pressure expression. The weak damping assumption not only ensures the consistency between the calculation accuracy and the actual scenario, but also greatly simplifies the expression structure, laying the foundation for the subsequent derivation of fluid velocity and acceleration.

[0039] For complex trigonometric function terms, define intermediate parameters. , This method simplifies the expression by associating pile dimensions (draft and diameter), wave number, and trigonometric functions. Simultaneously, it defines damping and attenuation coefficients, transforming physical parameters such as drag coefficient, pile diameter, and wave height into dimensionless or easily calculated coefficients, thus bridging the gap between physical parameters and mathematical expressions. However, the expression still contains scattered physical parameters and complex trigonometric functions, and directly merging these components could lead to redundancy. Defining intermediate parameters can "package" complex terms, reducing the mathematical complexity of subsequent derivations. This also clarifies the relationship between physical parameters (such as pile diameter and drag coefficient) and energy dissipation, facilitating subsequent parameter adjustments and engineering applications.

[0040] Waves can be described by the combined distribution of wave height, period (or frequency), and wave direction. To simplify the analysis, it is usually assumed that all wave heights are related to the average spectral peak period and the average wave direction. Assuming that the wave height distribution is an uncorrected Rayleigh distribution, the average energy dissipation is as follows.

[0041] S14. Based on the energy dissipation equation and the dynamic pressure expression, a statistical averaging process is performed to obtain the average energy dissipation expression under the random wave field, specifically: ; In the formula, This represents the average energy dissipation under a random wave field. This represents the wavenumber corresponding to the period of the spectral peak. This represents the wave angular frequency corresponding to the period of the spectral peak. This represents the third intermediate parameter. , Indicates the fourth intermediate parameter , Indicates wave height The Rayleigh probability density function.

[0042] In reality, ocean waves are randomly distributed (with varying wave heights and periods), rather than ideal waves with a single, fixed wave height. Based on the industry-consensus assumption that "wave height follows a Rayleigh distribution," the instantaneous energy dissipation is statistically averaged, and intermediate parameters are integrated with the Rayleigh probability density function to obtain an expression for the average energy dissipation under a random wave field. The derived results are more consistent with engineering practice, avoiding simulation errors caused by the single wave height assumption and improving the practicality of the parameterization scheme.

[0043] because And root mean square wave height Total energy of the waves The relationship is Then the expression for average energy dissipation can be simplified as follows.

[0044] S15. The expression for the average energy dissipation under the random wave field is simplified to obtain the first wave energy dissipation term caused by inertial force, specifically: ; In the formula, This represents the total energy of the wave.

[0045] Utilizing the generally accepted "fixed relationship between root mean square wave height and total wave energy" in the field of marine engineering By replacing the wave height parameter in the previous equation with the total wave energy, we finally obtain the average energy dissipation expression characterized only by the total wave energy, pile parameters, and intermediate coefficients. The total wave energy is a core fundamental parameter in wave models that is easily obtained. After transforming the dissipation term into a function of the total wave energy, it can be directly embedded into the wave action balance equation of the model for collaborative calculation without the need for additional complex observation data. This balances computational efficiency and engineering applicability, achieving accurate simulation of wave fields under the influence of large-scale wind farms.

[0046] S2. Add the first wave energy dissipation term to the wave model to obtain the improved wave model; Specifically, the first wave energy dissipation term is added to the vegetation module of the wave model to obtain an improved wave model. The vegetation module includes a second wave energy dissipation term caused by resistance.

[0047] In one alternative implementation, the formula for the energy dissipation term of the first wave is written into the vegetation module of the wave model (such as the SWAN model) using a programming language (such as Fortran), resulting in an improved wave model. This extends the original vegetation module into a wind turbine module. Figure 3 As shown.

[0048] S3. Obtain the parameters of the wind turbine piles of the offshore wind farm, including the pile diameter, draft, drag coefficient, and inertial force coefficient.

[0049] S4. Input the parameters into the improved wave model, perform wave field simulation on the sea area containing the offshore wind farm, and output the first wave field simulation result.

[0050] Specifically, the pile diameter, draft, drag coefficient, and inertial force coefficient are input into the improved wave model to simulate the wave field in the sea area containing the offshore wind farm, and the first wave field simulation result is output, such as... Figure 3 As shown.

[0051] In the model calculation, the wave energy dissipation term caused by inertial force will be substituted into the wave action balance equation along with other physical process source terms, such as wind input (a parameter that quantifies the energy supply of wind to waves, calculated by the model based on the input "wind speed and direction at a height of 10 meters above the sea surface" and "wind and wave interaction theory"), bottom friction (a parameter that quantifies the energy consumption of the seabed to waves, calculated by the model based on parameters such as "seabed roughness, wave period, and water depth"), and white cap dissipation (a parameter that quantifies the energy consumption when waves break up and produce white caps, calculated by the model based on "wave height and wave energy density"), to achieve a physical characterization of the impact on wind turbine piles.

[0052] In one alternative implementation, it further includes: The wave model is used to simulate the wave field in the sea area, and the second wave field simulation result is output.

[0053] S5. Evaluate the impact of the offshore wind farm on the ocean waves in the sea area based on the simulation results of the first wave field, and obtain the evaluation results.

[0054] Specifically, by comparing the simulation results of the first wave field and the simulation results of the second wave field, the influence of the offshore wind farm on the effective wave height (a direct manifestation of energy dissipation), average wave direction (wave propagation direction shift), and average wavelength (wave scale variation) of the ocean waves in the sea area is quantitatively evaluated, and the degree of modulation and spatial distribution characteristics of the offshore wind farm on the ocean waves are obtained.

[0055] To further illustrate the differences in inertial force and drag at different scales, the magnitudes of inertial force and drag were compared for cylinders with diameters of 10 m and 1 m, such as... Figure 4 As shown. When the incident wave height is 3 m, the drag coefficient is 1.2, the inertial force coefficient is 2, the water depth is 80 m, and the diameter is 10 m, the average wavelength of the incident wave is within 1700 m, and the inertial force is greater than the drag. However, when the cylinder diameter is 1 m, the inertial force is always less than the drag. As the wavelength increases (the relative size of the cylinder decreases), the drag increases relative to the inertial force, which is consistent with the assumption that the inertial force can be ignored in the vegetation module. However, for the wind turbine piles, especially when the pile diameter is large, the inertial force cannot be ignored. Figure 4 As shown, by comparing the forces of a large-diameter (wind turbine) and a small-diameter (vegetation), intuitive data is used to prove the core premise of the present invention—the wind turbine pile must consider both inertial force and resistance. The traditional vegetation module design, which only considers resistance, is not applicable, thus supporting the rationality of the technical solution of the present invention that modifies the vegetation module and adds an inertial force dissipation term.

[0056] According to another aspect of the invention, Figure 2This is a schematic diagram illustrating an assessment system for the impact of an offshore wind farm on ocean waves according to an embodiment of the present invention. The electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the various steps of the assessment method for the impact of an offshore wind farm on ocean waves as described above.

[0057] In summary, the method and system for assessing the impact of offshore wind farms on ocean waves described above overcome the limitations of traditional "dry grid point" methods or methods that only consider diffraction effects. By simultaneously considering drag and inertial forces, it more realistically reflects the interaction between large-diameter wind turbine piles and waves, resulting in a more complete physical mechanism. Furthermore, it avoids setting extremely high-resolution grids for each pile, making wave simulation of large-scale offshore wind farm areas computationally possible with high efficiency. This invention can be directly integrated into commonly used wave models, facilitating engineering practice and scientific research applications. It provides a more reliable technical tool for wind farm planning, marine environmental impact assessment, and coastal protection design, and has wide applicability.

[0058] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for assessing the impact of offshore wind farms on ocean waves, characterized in that, include: The energy dissipation term of the first wave caused by inertial force is derived based on physical principles; By adding the first wave energy dissipation term to the wave model, an improved wave model is obtained. Obtain the parameters of the wind turbine piles in an offshore wind farm; Input the parameters into the improved wave model, perform wave field simulation on the sea area containing the offshore wind farm, and output the first wave field simulation result; The impact of the offshore wind farm on ocean waves in the sea area is evaluated based on the simulation results of the first wave field, and the evaluation results are obtained.

2. The method for assessing the impact of offshore wind farms on ocean waves according to claim 1, characterized in that, Based on physical principles, the energy dissipation term of the first wave caused by inertial force is derived as follows: Based on the physical principle of energy consumption due to work done by inertial force and the interaction characteristics between wind turbine piles and fluid, an energy dissipation equation caused by inertial force is established based on the inertial force coefficient, fluid density, wind turbine pile volume, fluid horizontal velocity, wind turbine pile diameter, vertical distance from the seabed to the bottom of the wind turbine pile, and draft of the wind turbine pile. A dynamic pressure expression is established based on the continuity equation, momentum equation, seabed boundary conditions, and complex wave number of fluid mechanics. The dynamic pressure expression is simplified to obtain the simplified dynamic pressure expression; Based on the energy dissipation equation and the dynamic pressure expression, a statistical averaging process is performed to obtain the average energy dissipation expression under the random wave field. The expression for the average energy dissipation under the random wave field is simplified to obtain the first wave energy dissipation term caused by inertial force.

3. The method for assessing the impact of offshore wind farms on ocean waves according to claim 2, characterized in that, Based on the physical principle of energy dissipation due to inertial force and the interaction characteristics between the wind turbine pile and the fluid, an energy dissipation equation caused by inertial force is established based on the inertial force coefficient, fluid density, wind turbine pile volume, fluid horizontal velocity, wind turbine pile diameter, vertical distance from the seabed to the bottom of the wind turbine pile, and draft of the wind turbine pile. Specifically: ； In the formula, This indicates energy dissipation caused by inertial forces. This indicates the vertical distance from the seabed to the bottom of the wind turbine pile. This indicates the water depth of the wind turbine piles. Indicates water depth. Represents inertial force. Indicates the horizontal velocity of the fluid. Indicates the inertial force coefficient. Indicates fluid density, This indicates the volume of the wind turbine pile. Indicates the diameter of the wind turbine pile. Represents the spatial coordinates of the seawater in the vertical direction.

4. The method for assessing the impact of offshore wind farms on ocean waves according to claim 3, characterized in that, A dynamic pressure expression is established based on the continuity equation, momentum equation, seabed boundary conditions, and complex wave number of fluid mechanics, specifically as follows: ； ； ； In the formula, Indicates pressure. Represents gravitational acceleration. represents the wave height, Represents the complex wave number. Indicates the angular frequency of the wave. Indicates wave number, This represents the complex coefficients directly related to the complex wavenumber. Represents the imaginary unit. Represents the exponential decay coefficient. Indicates the horizontal distance along the direction of wave propagation. Indicates time, Represents the dimensionless damping coefficient; The dynamic pressure expression is simplified to obtain the simplified dynamic pressure expression, as follows: ； ； ； ； ； In the formula, This represents the dimensionless wave energy attenuation coefficient. Indicates the first intermediate parameter. This indicates the second intermediate parameter. This represents the drag coefficient.

5. The method for assessing the impact of offshore wind farms on ocean waves according to claim 4, characterized in that, Based on the energy dissipation equation and the dynamic pressure expression, a statistical averaging process is performed to obtain the average energy dissipation expression under the random wave field, specifically: ； In the formula, This represents the average energy dissipation under a random wave field. This represents the wavenumber corresponding to the period of the spectral peak. This represents the wave angular frequency corresponding to the period of the spectral peak. This represents the third intermediate parameter. This represents the fourth intermediate parameter. Indicates wave height The Rayleigh probability density function; The expression for the average energy dissipation under the random wave field is simplified to obtain the first wave energy dissipation term caused by inertial force, specifically: ； In the formula, This represents the total energy of the wave.

6. The method for assessing the impact of offshore wind farms on ocean waves according to claim 1, characterized in that, Adding the first wave energy dissipation term to the wave model yields the improved wave model, which includes: The first wave energy dissipation term is added to the vegetation module of the wave model to obtain an improved wave model. The vegetation module includes a second wave energy dissipation term caused by resistance.

7. The method for assessing the impact of offshore wind farms on ocean waves according to claim 1, characterized in that, The parameters include pile diameter, draft, resistance coefficient, and inertial force coefficient. The parameters are input into the improved wave model, and wave field simulation is performed on the sea area containing the offshore wind farm. The first wave field simulation result is output, including: The pile diameter, draft, drag coefficient, and inertial force coefficient are input into the improved wave model to simulate the wave field in the sea area containing the offshore wind farm, and the first wave field simulation result is output.

8. The method for assessing the impact of offshore wind farms on ocean waves according to claim 1, characterized in that, Also includes: The wave model is used to simulate the wave field in the sea area, and the second wave field simulation result is output.

9. A method for assessing the impact of offshore wind farms on ocean waves according to claim 8, characterized in that, The impact of the offshore wind farm on ocean waves in the sea area was evaluated based on the simulation results of the first wave field. The evaluation results include: By comparing the simulation results of the first wave field and the simulation results of the second wave field, the influence of the offshore wind farm on the effective wave height, average wave direction and average wavelength of the ocean waves in the sea area is quantitatively evaluated, and the modulation degree and spatial distribution characteristics of the ocean waves by the offshore wind farm are obtained.

10. A system for assessing the impact of offshore wind farms on ocean waves, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements each step of the method for assessing the impact of an offshore wind farm on ocean waves according to any one of claims 1 to 9.

Images