A method and system for modeling ocean current velocity based on wind-wave-current coupling relationship

Abstract

The present invention provides a method and system for modeling ocean current velocity based on the wind-wave-current coupling relationship. A first fluctuating wind speed model is established based on characteristic parameters of the ocean breeze and the ocean wave under different ocean conditions, and a specific calculation method is used to calculate the power spectrum density of the fluctuating wind speed. In addition, a relationship between the power spectrum density and the amplitude of the fluctuating wind speed is constructed within the angular frequency range. A second fluctuating wind speed model is then obtained through the relationship and the first fluctuating wind speed model, and the absolute wind speed of the ocean breeze is calculated. The significant wave height of the ocean wave is calculated according to the absolute wind speed, and a specific calculation method is used to calculate the velocities of the wind-induced current and the wave-induced current, respectively, and thus an ocean current velocity model is constructed. By fully considering the mutual influence between the ocean breeze, ocean waves and ocean currents, a more accurate and comprehensive ocean current velocity model can be provided, which is of great significance for understanding and responding to complex ocean environments.

Description

Technical Field

[0001] The present invention relates to the technical field of ship engineering and ocean engineering, and in particular to a method and system for modeling ocean current velocity based on the wind-wave-current coupling relationship. Background Art

[0002] The 21st century is widely recognized as the "Ocean Century." The vast ocean, covering over 70% of the Earth's surface, boasts a wealth of biological and energy resources, providing a crucial safeguard against future food and energy crises. Since the beginning of the 21st century, significant breakthroughs in marine science and technology have fueled the vigorous development of the marine industry and facilitated the development and utilization of marine resources. With the continuous advancement of marine science and technology and the acceleration of globalization, the marine industry, primarily focused on offshore oil and gas, port shipping, marine tourism, and marine fisheries, has become a crucial pillar of economic development in various countries. To capitalize on the development trends of the "Ocean Century," my country has established the important strategic task of "building a strong maritime nation."

[0003] As a major maritime nation, my country boasts vast maritime territory and a long coastline, boasting over 6,500 islands and abundant marine resources, including approximately 40 billion tons of marine oil and gas. With its continuous development, my country's marine economy has become a vital component of its overall economy. In 2023, my country's marine GDP reached 9.9097 trillion yuan, accounting for 7.9% of GDP. Marine industries such as port shipping and shipbuilding play a key role in this. my country boasts a massive maritime transport volume, particularly container transport, ranking first in the world. In 2023, my country occupied seven of the top ten ports in terms of global throughput. my country's shipbuilding industry continues to lead the world in terms of volume. In 2023, my country's international market share in shipbuilding completions, backlog, and new orders all ranked first globally. The industry has successfully delivered numerous large vessels, including 24,000 TEU ultra-large container ships, ultra-large ethylene carriers, and large cruise ships.

[0004] Large ships are affected by the marine environment during ocean voyages. Sea breezes, waves, and currents are the most significant environmental factors affecting their motion. Sea breezes refer to the movement of air along the pressure gradient at sea. Waves refer to the fluctuations of ocean water, where "fluctuation" is the periodic or quasi-periodic movement of water particles out of their equilibrium positions under the influence of external forces. Currents refer to the relatively stable, large-scale flow of seawater, where "relatively stable flow" means flow with roughly similar direction, velocity, and path over large spatial scales and long periods of time. Sea breezes refer to the movement of air along the pressure gradient at sea. As a significant energy source for the global ocean, sea breezes influence the formation of waves and currents. Furthermore, due to my country's vast maritime territory and large shipping volumes, navigation operations in complex marine environments may sometimes be required. To ensure safe and stable navigation and smooth operations at sea, it is necessary to understand the mechanisms by which the marine environment influences the motion of large ships. The marine environment primarily impacts ships through the action of sea breezes, waves, and currents. The characteristics of sea breezes, waves, and currents vary in different sea conditions, resulting in varying disturbances on ships.

[0005] In summary, the ocean's winds, waves, and currents interact with each other, creating a complex coupling relationship. This makes it difficult to simulate wind, wave, and currents based on their generation mechanisms. Current research often simulates winds, waves, and currents separately based on mathematical models fitted from measured data. However, this approach fails to fully account for the interplay between wind, wave, and current models, and cannot realistically simulate the wind, wave, and current environment under varying sea conditions. Summary of the Invention

[0006] The present invention addresses the problems that exist in the current ocean current velocity modeling process, such as the failure to consider the mutual influence between sea breeze, waves, and ocean current models, and the inability to truly simulate the wind, wave, and current environment under different sea conditions. A method for ocean current velocity modeling based on the wind-wave-current coupling relationship is provided. Based on the characteristic parameters of sea breeze and waves under different sea conditions, a specific calculation method is used to construct a fluctuating wind speed model to calculate the fluctuating wind speed and the significant wave height of the waves, and then to construct an ocean current velocity model. By fully considering the mutual influence between sea breeze, waves, and ocean currents, a more accurate and comprehensive ocean current velocity model can be provided, which is of great significance for understanding and responding to complex marine environments. The present invention also relates to an ocean current velocity modeling system based on the wind-wave-current coupling relationship.

[0007] The technical solutions of the present invention are as follows:

[0008] A method for modeling ocean current velocity based on wind-wave-current coupling, characterized by comprising the following steps:

[0009] Parameter acquisition step: acquiring sea breeze characteristic parameters and wave characteristic parameters under different sea conditions, wherein the sea breeze characteristic parameters include the circular frequency of the fluctuating wind speed, the average wind speed at sea level, the correlation length of the wind speed fluctuation, and the amplitude, angular frequency and initial phase of each simple harmonic wave of the fluctuating wind speed; and the wave characteristic parameters include the circular frequency, amplitude and wave number of the waves;

[0010] Power spectrum density calculation steps: Calculate the average value of the circular frequency of the fluctuating wind speed based on the circular frequency of the fluctuating wind speed, the average wind speed at sea level, and the correlation length of the wind speed fluctuations, and calculate the power spectrum density of the fluctuating wind speed based on the average value of the circular frequency of the fluctuating wind speed, the average wind speed at sea level, and the correlation length of the wind speed fluctuations;

[0011] The first fluctuating wind speed model and relationship establishment step includes: establishing the first fluctuating wind speed model based on the amplitude, angular frequency, and initial phase of each simple harmonic wave of the fluctuating wind speed; establishing an angular frequency interval based on the angular frequency and a frequency bandwidth set based on the angular frequency; and constructing a relationship between the power spectral density and the amplitude of the fluctuating wind speed when the angular frequency is within the angular frequency interval;

[0012] Absolute wind speed calculation steps: Based on the relationship between the power spectrum density and amplitude of the fluctuating wind speed and the first fluctuating wind speed model, a second fluctuating wind speed model is obtained to further calculate the fluctuating wind speed; the absolute wind speed of the sea breeze is calculated based on the fluctuating wind speed and the average wind speed at sea level;

[0013] The steps for constructing the ocean current velocity model are as follows: the significant wave height of the waves is calculated based on the absolute wind speed of the sea breeze, and the water friction velocity is calculated based on the average wind speed, air density and seawater density at sea level. Then, the velocity of the wind-induced current is calculated based on the water friction velocity; the velocity of the wave-induced current is calculated based on the significant wave height, circular frequency, amplitude and wave number of the waves, and the ocean current velocity model is constructed based on the velocity of the wind-induced current and the velocity of the wave-induced current.

[0014] Preferably, in the step of establishing the first pulsating wind speed model and the relationship, establishing the angular frequency interval according to the angular frequency and the bandwidth set based on the angular frequency includes: using the frequency equal division method to divide the wave spectrum frequency range under multiple different sea conditions into multiple parts, and setting the length of each part as the bandwidth, and establishing the angular frequency interval of each wave spectrum frequency according to the angular frequency and the bandwidth.

[0015] Preferably, in the parameter acquisition and coordinate system establishment steps, the wave characteristic parameters also include wavelength, and the wave number is calculated based on the wavelength.

[0016] Preferably, in the parameter acquisition step, when obtaining the correlation length of wind speed fluctuations, the correlation length of wind speed fluctuations is obtained by performing statistical analysis on wind speed data at multiple different time points to improve the adaptability of the model to wind speed changes on different time scales.

[0017] A current velocity modeling system based on the wind-wave-current coupling relationship is characterized by comprising a parameter acquisition module, a power spectrum density calculation module, a first fluctuating wind speed model and relationship establishment module, an absolute wind speed calculation module, and a current velocity model construction module connected in sequence.

[0018] The parameter acquisition module acquires sea breeze characteristic parameters and ocean wave characteristic parameters under different sea conditions, wherein the sea breeze characteristic parameters include the circular frequency of the fluctuating wind speed, the average wind speed at sea level, the correlation length of the wind speed fluctuation, and the amplitude, angular frequency and initial phase of each simple harmonic wave of the fluctuating wind speed; and the ocean wave characteristic parameters include the circular frequency, amplitude and wave number of the waves;

[0019] The power spectrum density calculation module calculates the average value of the circular frequency of the fluctuating wind speed according to the circular frequency of the fluctuating wind speed, the average wind speed at sea level, and the correlation length of the wind speed fluctuation, and calculates the power spectrum density of the fluctuating wind speed according to the average value of the circular frequency of the fluctuating wind speed, the average wind speed at sea level, and the correlation length of the wind speed fluctuation;

[0020] The first fluctuating wind speed model and relationship establishment module establishes the first fluctuating wind speed model based on the amplitude, angular frequency, and initial phase of each simple harmonic wave of the fluctuating wind speed; establishes an angular frequency interval based on the angular frequency and a bandwidth set based on the angular frequency, and constructs a relationship between the power spectrum density and the amplitude of the fluctuating wind speed when the angular frequency is within the angular frequency interval;

[0021] The absolute wind speed calculation module obtains a second fluctuating wind speed model based on the relationship between the power spectrum density and amplitude of the fluctuating wind speed and the first fluctuating wind speed model, and then calculates the fluctuating wind speed; and calculates the absolute wind speed of the sea breeze based on the fluctuating wind speed and the average wind speed at sea level;

[0022] The ocean current velocity model construction module calculates the significant wave height of the waves based on the absolute wind speed of the sea breeze, and calculates the water friction velocity based on the average wind speed, air density and seawater density at sea level, and then calculates the flow velocity of the wind-induced flow based on the water friction velocity; then calculates the flow velocity of the wave-induced flow based on the significant wave height, circular frequency, amplitude and wave number of the waves, and constructs an ocean current velocity model based on the flow velocity of the wind-induced flow and the flow velocity of the wave-induced flow.

[0023] Preferably, in the first pulsating wind speed model and relationship establishment module, establishing the angular frequency interval according to the angular frequency and the bandwidth set based on the angular frequency includes: using the frequency equal division method to divide the wave spectrum frequency range under multiple different sea conditions into multiple parts, and setting the length of each part as the bandwidth, and establishing the angular frequency interval of each wave spectrum frequency according to the angular frequency and the bandwidth.

[0024] Preferably, the ocean wave characteristic parameters also include wavelength, and the wave number is calculated based on the wavelength.

[0025] Preferably, in the parameter acquisition module, when obtaining the correlation length of wind speed fluctuation, the correlation length of wind speed fluctuation is obtained by statistically analyzing the wind speed data at multiple different time points, so as to improve the adaptability of the model to wind speed changes on different time scales.

[0026] The beneficial effects of the present invention are:

[0027] The present invention provides a method for modeling ocean current velocity based on the wind-wave-current coupling relationship. The method is based on the characteristic parameters of sea breeze and ocean waves under different sea conditions, and adopts a specific calculation method to calculate the power spectrum density of the pulsating wind speed, which can effectively reveal the energy distribution of wind speed fluctuations; then, a first pulsating wind speed model is established based on the amplitude, angular frequency and initial phase of each simple harmonic wave of the pulsating wind speed, which can more finely describe the random variation characteristics of the wind speed, capture the details in the wind speed variation, and improve the authenticity and reliability of the model; and an angular frequency interval is established according to the angular frequency and the bandwidth set based on the angular frequency. When the angular frequency is within the angular frequency interval, a relationship between the power spectrum density and the amplitude of the pulsating wind speed is constructed, which can better identify the degree to which different frequency components contribute to the total wind speed, help identify the main disturbance source, and thus optimize the prediction model. It can intuitively display the energy distribution of different frequency components; finally, the significant wave height of the waves is calculated according to the absolute wind speed of the sea breeze, fully considering the influence of wind speed on the waves, which is helpful to comprehensively evaluate the effect of wind on the wave shape of the sea surface; and the water friction speed is calculated according to the average wind speed, air density and seawater density at sea level, and then the flow rate of the wind-induced current is calculated according to the water friction speed, which can more comprehensively describe the influence of wind on the movement of sea water; and the flow rate of the wave-induced current is calculated according to the significant wave height, circular frequency, amplitude and wave number of the waves, which can more comprehensively describe the influence of waves on ocean currents; an ocean current velocity model is constructed based on the flow rate of wind-induced current and the flow rate of wave-induced current. The present invention can provide a more accurate and comprehensive ocean current velocity model by comprehensively considering the interaction between wind, waves and currents, which is of great significance for understanding and responding to complex marine environments.

[0028] The present invention also relates to a current velocity modeling system based on the wind-wave-current coupling relationship. The system corresponds to the above-mentioned current velocity modeling method based on the wind-wave-current coupling relationship, and can be understood as a system that implements the above-mentioned current velocity modeling method based on the wind-wave-current coupling relationship, including a parameter acquisition module, a power spectrum density calculation module, a first pulsating wind speed model and relationship establishment module, an absolute wind speed calculation module and a current velocity model construction module connected in sequence. The modules cooperate with each other, based on the sea breeze characteristic parameters and wave characteristic parameters under different sea conditions, and adopt a specific calculation method to construct a pulsating wind speed model to calculate the pulsating wind speed and the significant wave height of the waves, and then construct an ocean current velocity model. By fully considering the mutual influence between sea breeze, waves and currents, a more accurate and comprehensive ocean current velocity model can be provided, which is of great significance for understanding and responding to the complex marine environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flow chart of the ocean current velocity modeling method based on the wind-wave-current coupling relationship of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be described below with reference to the accompanying drawings.

[0031] The present invention relates to a method for modeling ocean current velocity based on the wind-wave-current coupling relationship. The flow chart of the method is as follows: Figure 1 As shown, the following steps are included in sequence:

[0032] Parameter acquisition step: Acquire sea breeze characteristic parameters and wave characteristic parameters under different sea conditions. The sea breeze characteristic parameters include the circular frequency of the fluctuating wind speed, the average wind speed at sea level, the correlation length of the wind speed fluctuation, and the amplitude, angular frequency, and initial phase of each simple harmonic wave of the fluctuating wind speed. The wave characteristic parameters include the circular frequency, amplitude, and wave number of the waves. Preferably, the wave characteristic parameters also include the wavelength, and the wave number is calculated based on the wavelength. That is, the wave number k and the wavelength λ have the following relationship: k = 2π / λ.

[0033] The power spectrum density calculation steps are as follows: the average value of the circular frequency of the fluctuating wind speed is calculated based on the circular frequency of the fluctuating wind speed, the average wind speed at sea level, and the correlation length of the wind speed fluctuations; and the power spectrum density of the fluctuating wind speed is calculated based on the average value of the circular frequency of the fluctuating wind speed, the average wind speed at sea level, and the correlation length of the wind speed fluctuations.

[0034] Specifically, for the fluctuating wind speed of the sea breeze, there is a fluctuating wind speed spectral density function. First, the average value of the fluctuating wind speed circular frequency is calculated based on the circular frequency ω of the fluctuating wind speed, the average wind speed V at sea level, and the correlation length L of the wind speed fluctuation. The power spectrum density of the fluctuating wind speed is calculated based on the average value of the circular frequency of the fluctuating wind speed, the average wind speed at sea level, and the correlation length of the wind speed fluctuation. Here, the Harris wind spectrum is used. The power spectrum density function S of the fluctuating wind speed is u (ω) is expressed as:

[0035]

[0036] Where ω is the circular frequency of the fluctuating wind speed; is the average wind speed at 10 m above sea level; κ is the surface drag coefficient (κ = 0.0025); L is the correlation length unit of wind speed fluctuation (L = 1200 m), which is used to describe the spatial correlation of wind speed fluctuations, that is, the distance over which wind speed fluctuations are correlated.

[0037] The first fluctuating wind speed model and relationship establishment steps are as follows: the first fluctuating wind speed model is established based on the amplitude, angular frequency and initial phase of each simple harmonic wave of the fluctuating wind speed; and an angular frequency interval is established according to the angular frequency and the bandwidth set based on the angular frequency. When the angular frequency is within the angular frequency interval, a relationship between the power spectral density and the amplitude of the fluctuating wind speed is constructed.

[0038] Specifically, first, a first fluctuating wind speed model is established based on the amplitude, angular frequency, and initial phase of each simple harmonic wave of the fluctuating wind speed. The first fluctuating wind speed model is expressed as follows:

[0039]

[0040] In the above formula, represents the amplitude of the nth simple harmonic wave of the pulsating wind speed, represents the angular frequency of the nth simple harmonic wave of the fluctuating wind speed at time t, ε n Indicates the initial phase of the nth simple harmonic wave of the fluctuating wind speed.

[0041] Then, the angular frequency interval is established according to the angular frequency ω and the bandwidth Δω set based on the angular frequency.

[0042] It should be noted that, in theory, the angular frequency interval (also called the wave spectrum frequency range) is [0, +∞], but in actual simulations, different wave spectrum frequency ranges are selected for different sea conditions, as shown in Table 1.

[0043] Table 1

[0044]

[0045] Preferably, the frequency division method is used to divide the frequency range of the wave spectrum under multiple different sea conditions into multiple parts, and the length of each part is set as the bandwidth, and the angular frequency interval of each wave spectrum frequency is established according to the angular frequency and the bandwidth. That is, the frequency division method is used to divide the frequency range of the wave spectrum into N parts, and the length of each part is Δω. Then the frequency range of each part is when When the angular frequency is within the angular frequency interval, the relationship between the power spectrum density and amplitude of the fluctuating wind speed is constructed, that is, the amplitude (amplitude) of the fluctuating wind speed and the power spectrum density S u The following relationship exists:

[0046]

[0047] Here, ρ is the density of seawater.

[0048] Absolute wind speed calculation steps: Based on the relationship between the power spectrum density and amplitude of the fluctuating wind speed and the first fluctuating wind speed model, a second fluctuating wind speed model is obtained to further calculate the fluctuating wind speed; the absolute wind speed of the sea breeze is calculated based on the fluctuating wind speed and the average wind speed at sea level.

[0049] Specifically, firstly based on the relationship between the power spectrum density and amplitude of the fluctuating wind speed and the first fluctuating wind speed model, that is, according to

[0050] Equation 3 and Equation 2 give the second fluctuating wind speed model, as shown below:

[0051]

[0052] According to the second fluctuating wind speed model, the fluctuating wind speed v can be calculated wind , according to the pulsating wind speed v wind and the average wind speed at sea level Calculate the absolute wind speed V of the sea breeze wind , calculated according to the following formula:

[0053]

[0054] The steps for constructing the ocean current velocity model are as follows: the significant wave height of the waves is calculated based on the absolute wind speed of the sea breeze, and the water friction velocity is calculated based on the average wind speed, air density and seawater density at sea level. Then, the velocity of the wind-induced current is calculated based on the water friction velocity; the velocity of the wave-induced current is calculated based on the significant wave height, circular frequency, amplitude and wave number of the waves, and the ocean current velocity model is constructed based on the velocity of the wind-induced current and the velocity of the wave-induced current.

[0055] Specifically, first, according to the absolute wind speed V of the sea breeze wind Calculate the significant wave height H of the ocean wave 1 / 3 , calculated according to the following formula:

[0056]

[0057] Then the water friction velocity u is calculated based on the average wind speed, air density and seawater density at sea level. *w , calculated according to the following formula:

[0058]

[0059] Among them, C z is the wind stress coefficient, C v is the wave resistance coefficient, is the average wind speed at height z above sea level, ρ a is the air density, ρ w is the density of seawater.

[0060] Among them, the wind stress coefficient C z The calculation formula is:

[0061]

[0062] In the above formula, a is the Charnock coefficient, which is 0.185; F r The calculation formula for the Froude number is:

[0063]

[0064] The recommended calculation formula for height z is:

[0065] z=7.35R 2 / 3 ×10 -7 (10)

[0066] In the above formula, R is the wind Reynolds number, and the calculation formula is:

[0067]

[0068] In the above formula, ν a is the dynamic viscosity of air; L wind The wind range usually refers to the distance of open waters that the wind blows through. The value here refers to the minimum wind zone length under full development conditions of different sea conditions.

[0069] According to the water friction speed u *w Calculate the velocity of wind-induced flow (also known as Ekman transport) according to the following formula:

[0070] V n =22u *w (12)

[0071] Then, the velocity of the wave-induced flow (also known as Stokes transport) is calculated based on the significant wave height, circular frequency, amplitude, and wave number. The velocity of the wave-induced flow V is v The calculation formula is:

[0072]

[0073] Where ω is the circular frequency of the wave, ζ a is the amplitude (wave amplitude), H 1 / 3 is the significant wave height, and k is the wave number.

[0074] Finally, the ocean current velocity model is constructed based on the velocity of wind-induced current and wave-induced current. The ocean current velocity (i.e. the velocity of ocean surface current) V c It can be expressed as:

[0075] V c =V n +V v (14)

[0076] The present invention also relates to a current velocity modeling system based on the wind-wave-current coupling relationship. The system corresponds to the above-mentioned current velocity modeling method based on the wind-wave-current coupling relationship and can be understood as a system for implementing the above-mentioned method. The system includes a parameter acquisition module, a power spectrum density calculation module, a first pulsating wind speed model and relationship establishment module, an absolute wind speed calculation module, and a current velocity model construction module connected in sequence. Specifically,

[0077] The parameter acquisition module acquires sea breeze characteristic parameters and ocean wave characteristic parameters under different sea conditions, wherein the sea breeze characteristic parameters include the circular frequency of the fluctuating wind speed, the average wind speed at sea level, the correlation length of the wind speed fluctuation, and the amplitude, angular frequency and initial phase of each simple harmonic wave of the fluctuating wind speed; and the ocean wave characteristic parameters include the circular frequency, amplitude and wave number of the waves;

[0078] The power spectrum density calculation module calculates the average value of the circular frequency of the fluctuating wind speed according to the circular frequency of the fluctuating wind speed, the average wind speed at sea level, and the correlation length of the wind speed fluctuation, and calculates the power spectrum density of the fluctuating wind speed according to the average value of the circular frequency of the fluctuating wind speed, the average wind speed at sea level, and the correlation length of the wind speed fluctuation;

[0079] The first fluctuating wind speed model and relationship establishment module establishes the first fluctuating wind speed model based on the amplitude, angular frequency, and initial phase of each simple harmonic wave of the fluctuating wind speed; establishes an angular frequency interval based on the angular frequency and a bandwidth set based on the angular frequency, and constructs a relationship between the power spectrum density and the amplitude of the fluctuating wind speed when the angular frequency is within the angular frequency interval;

[0080] The absolute wind speed calculation module obtains a second fluctuating wind speed model based on the relationship between the power spectrum density and amplitude of the fluctuating wind speed and the first fluctuating wind speed model, and then calculates the fluctuating wind speed; and calculates the absolute wind speed of the sea breeze based on the fluctuating wind speed and the average wind speed at sea level;

[0081] The ocean current velocity model construction module calculates the significant wave height of the waves based on the absolute wind speed of the sea breeze, and calculates the water friction velocity based on the average wind speed, air density and seawater density at sea level, and then calculates the flow velocity of the wind-induced flow based on the water friction velocity; then calculates the flow velocity of the wave-induced flow based on the significant wave height, circular frequency, amplitude and wave number of the waves, and constructs an ocean current velocity model based on the flow velocity of the wind-induced flow and the flow velocity of the wave-induced flow.

[0082] Preferably, in the first pulsating wind speed model and relationship establishment module, establishing the angular frequency interval according to the angular frequency and the bandwidth set based on the angular frequency includes: using the frequency equal division method to divide the wave spectrum frequency range under multiple different sea conditions into multiple parts, and setting the length of each part as the bandwidth, and establishing the angular frequency interval of each wave spectrum frequency according to the angular frequency and the bandwidth.

[0083] Preferably, the ocean wave characteristic parameter also includes wavelength, and the wave number is calculated based on the wavelength.

[0084] Preferably, in the parameter acquisition module, when obtaining the correlation length of wind speed fluctuation, the correlation length of wind speed fluctuation is obtained by statistically analyzing the wind speed data at multiple different time points to improve the adaptability of the model to wind speed changes on different time scales.

[0085] The present invention provides an objective and scientific ocean current velocity modeling method and system based on the wind-wave-current coupling relationship. Based on the characteristic parameters of the sea breeze and the characteristic parameters of the waves under different sea conditions, a pulsating wind speed model is constructed using a specific calculation method to calculate the pulsating wind speed and the significant wave height of the waves, and then the ocean current velocity model is constructed. By fully considering the mutual influence between the sea breeze, waves and ocean currents, a more accurate and comprehensive ocean current velocity model can be provided, which is of great significance for understanding and responding to the complex marine environment.

[0086] It should be noted that the specific embodiments described above can enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. Therefore, although this specification has described the present invention in detail with reference to the drawings and embodiments, those skilled in the art should understand that the present invention can still be modified or replaced with equivalents. In short, all technical solutions and improvements that do not depart from the spirit and scope of the present invention should be included in the scope of protection of the patent for the present invention.

Claims

1. A method for modeling ocean current velocity based on the wind-wave-current coupling relationship, characterized in that: The following steps are involved: Parameter acquisition step: acquiring sea breeze characteristic parameters and wave characteristic parameters under different sea conditions, wherein the sea breeze characteristic parameters include the circular frequency of the fluctuating wind speed, the average wind speed at sea level, the correlation length of the wind speed fluctuation, and the amplitude, angular frequency and initial phase of each simple harmonic wave of the fluctuating wind speed; and the wave characteristic parameters include the circular frequency, amplitude and wave number of the waves; Power spectrum density calculation steps: Calculate the average value of the circular frequency of the fluctuating wind speed based on the circular frequency of the fluctuating wind speed, the average wind speed at sea level, and the correlation length of the wind speed fluctuations, and calculate the power spectrum density of the fluctuating wind speed based on the average value of the circular frequency of the fluctuating wind speed, the average wind speed at sea level, and the correlation length of the wind speed fluctuations; The first fluctuating wind speed model and relationship establishment step includes: establishing the first fluctuating wind speed model based on the amplitude, angular frequency, and initial phase of each simple harmonic wave of the fluctuating wind speed; establishing an angular frequency interval based on the angular frequency and a frequency bandwidth set based on the angular frequency; and constructing a relationship between the power spectral density and the amplitude of the fluctuating wind speed when the angular frequency is within the angular frequency interval; Absolute wind speed calculation steps: Based on the relationship between the power spectrum density and amplitude of the fluctuating wind speed and the first fluctuating wind speed model, a second fluctuating wind speed model is obtained to further calculate the fluctuating wind speed; the absolute wind speed of the sea breeze is calculated based on the fluctuating wind speed and the average wind speed at sea level; The steps of constructing the ocean current velocity model are as follows: the significant wave height is calculated based on the absolute wind speed of the sea breeze, and the water friction velocity is calculated based on the average wind speed, air density and seawater density at the sea level. The velocity of the wind-induced current is then calculated based on the water friction velocity. The velocity of the wave-induced current is then calculated based on the significant wave height, circular frequency, amplitude and wave number, and the ocean current velocity model is constructed based on the velocity of the wind-induced current and the velocity of the wave-induced current.

2. The ocean current velocity modeling method based on wind-wave-current coupling relationship according to claim 1 is characterized in that: In the step of establishing the first pulsating wind speed model and the relationship, establishing the angular frequency interval according to the angular frequency and the bandwidth set based on the angular frequency includes: using the frequency equal division method to divide the wave spectrum frequency range under multiple different sea conditions into multiple parts, and setting the length of each part as the bandwidth, and establishing the angular frequency interval of each wave spectrum frequency according to the angular frequency and the bandwidth.

3. The ocean current velocity modeling method based on wind-wave-current coupling relationship according to claim 1 is characterized in that: In the parameter acquisition and coordinate system establishment steps, the wave characteristic parameters also include wavelength, and the wave number is calculated based on the wavelength.

4. The ocean current velocity modeling method based on wind-wave-current coupling relationship according to claim 1 is characterized in that: In the parameter acquisition step, when obtaining the correlation length of wind speed fluctuation, the correlation length of wind speed fluctuation is obtained by statistically analyzing the wind speed data at multiple different time points to improve the adaptability of the model to wind speed changes on different time scales.

5. A current velocity modeling system based on wind-wave-current coupling relationship, characterized in that: It includes a parameter acquisition module, a power spectrum density calculation module, a first pulsating wind speed model and relationship establishment module, an absolute wind speed calculation module and an ocean current velocity model construction module, which are connected in sequence. The parameter acquisition module acquires sea breeze characteristic parameters and ocean wave characteristic parameters under different sea conditions, wherein the sea breeze characteristic parameters include the circular frequency of the fluctuating wind speed, the average wind speed at sea level, the correlation length of the wind speed fluctuation, and the amplitude, angular frequency and initial phase of each simple harmonic wave of the fluctuating wind speed; and the ocean wave characteristic parameters include the circular frequency, amplitude and wave number of the waves; The power spectrum density calculation module calculates the average value of the circular frequency of the fluctuating wind speed according to the circular frequency of the fluctuating wind speed, the average wind speed at sea level, and the correlation length of the wind speed fluctuation, and calculates the power spectrum density of the fluctuating wind speed according to the average value of the circular frequency of the fluctuating wind speed, the average wind speed at sea level, and the correlation length of the wind speed fluctuation; The first fluctuating wind speed model and relationship establishment module establishes the first fluctuating wind speed model based on the amplitude, angular frequency, and initial phase of each simple harmonic wave of the fluctuating wind speed; establishes an angular frequency interval based on the angular frequency and a bandwidth set based on the angular frequency, and constructs a relationship between the power spectrum density and the amplitude of the fluctuating wind speed when the angular frequency is within the angular frequency interval; The absolute wind speed calculation module obtains a second fluctuating wind speed model based on the relationship between the power spectrum density and amplitude of the fluctuating wind speed and the first fluctuating wind speed model, and then calculates the fluctuating wind speed; and calculates the absolute wind speed of the sea breeze based on the fluctuating wind speed and the average wind speed at sea level; The ocean current velocity model construction module calculates the significant wave height of the ocean waves based on the absolute wind speed of the sea breeze, and calculates the water friction velocity based on the average wind speed, air density and seawater density at the sea level, and then calculates the flow velocity of the wind-induced flow based on the water friction velocity; The velocity of the wave-induced current is then calculated based on the significant wave height, circular frequency, amplitude and wave number, and the ocean current velocity model is constructed based on the velocity of the wind-induced current and the velocity of the wave-induced current.

6. The ocean current velocity modeling system based on wind-wave-current coupling relationship according to claim 5 is characterized in that: In the first pulsating wind speed model and relationship establishment module, establishing an angular frequency interval according to the angular frequency and the bandwidth set based on the angular frequency includes: using a frequency equal division method to divide the wave spectrum frequency range under multiple different sea conditions into multiple parts, and setting the length of each part as the bandwidth, and establishing an angular frequency interval for each wave spectrum frequency according to the angular frequency and the bandwidth.

7. The ocean current velocity modeling system based on wind-wave-current coupling relationship according to claim 5 is characterized in that: The ocean wave characteristic parameters also include wavelength, and the wave number is calculated based on the wavelength.

8. The ocean current velocity modeling system based on wind-wave-current coupling relationship according to claim 5 is characterized in that: In the parameter acquisition module, when obtaining the correlation length of wind speed fluctuation, the correlation length of wind speed fluctuation is obtained by statistically analyzing the wind speed data at multiple different time points, so as to improve the adaptability of the model to wind speed changes on different time scales.

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