Ocean current flow velocity modeling method and system based on wind wave flow coupling relation

Abstract

The invention provides an ocean current flow velocity modeling method and system based on a wind wave flow coupling relation, and the method comprises the steps: building a first fluctuating wind speed model based on sea wind characteristic parameters and sea wave characteristic parameters under different sea conditions, calculating the power spectrum density of fluctuating wind speed through employing a specific calculation method, and carrying out the calculation of the power spectrum density of the fluctuating wind speed in an angular frequency interval range; constructing a relational expression between the power spectrum density and the amplitude of the fluctuating wind speed; a second fluctuating wind speed model is obtained through the relational expression and the first fluctuating wind speed model, and then the absolute wind speed of the sea wind is calculated; according to the method, the sexual wave height of sea waves is calculated according to the absolute wind speed, the flow velocity of wind-induced flow and the flow velocity of wave-induced flow are respectively calculated by adopting a specific calculation method, then an ocean current flow velocity model is constructed, and the more accurate and comprehensive ocean current flow velocity model can be provided by fully considering the mutual influence among sea wind, sea waves and ocean currents. The method is of great significance in understanding and coping with a complex marine environment.

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 recognized as the "Ocean Century". The vast ocean, which covers more than 70% of the earth's surface, has rich biological and energy resources, and is an important guarantee for facing food and energy crises in the future. Since the 21st century, marine science and technology have made major breakthroughs, promoting the vigorous development of the marine industry and promoting the development and utilization of marine resources. With the continuous advancement of marine science and technology and the acceleration of the globalization process, the marine industry, mainly marine oil and gas, port shipping, marine tourism and marine fisheries, has become an important pillar of economic development in various countries. In order to grasp the development trend of the "Ocean Century", my country has put forward the important strategic task of "building a strong maritime nation".

[0003] As a maritime power, my country has vast seas and long coastlines, more than 6,500 islands, about 40 billion tons of marine oil and gas and other rich marine resources. With continuous development, my country's marine economy has become an important part of my country's overall economy. In 2023, my country's marine GDP was 9909.7 billion yuan, accounting for 7.9% of GDP, among which my country's port shipping, shipbuilding and other marine industries played a key role. my country's marine transportation volume is huge, especially container transportation volume, which is the world's first. In 2023, my country occupied 7 seats in the top ten ports in the world in terms of throughput; my country's shipbuilding industry continued to lead the world in terms of total volume. In 2023, my country's shipbuilding industry completed volume, backlog of orders, and international market share of new orders were all the first in the world, and successfully delivered many large ships such as 24,000TEU ultra-large container ships, ultra-large ethylene carriers, and large cruise ships.

[0004] Large ships will be affected by the marine environment during their ocean voyages, among which sea breeze, waves and currents are the most important environmental factors affecting the movement of large ships. Sea breeze refers to the flow of air at sea along the pressure gradient. Sea waves refer to the fluctuation of seawater in the ocean, where "fluctuation" refers to the periodic or quasi-periodic movement of water particles away from the equilibrium position under the action of external forces. Ocean current refers to the large-scale relatively stable flow of seawater, where "large-scale relatively stable flow" means the flow with roughly similar direction, speed and flow path in a large-scale space and over a long period of time. Sea breeze refers to the flow of air at sea along the pressure gradient. As an important source of energy for the global ocean, sea breeze affects the formation of waves and currents. In addition, due to the vast sea territory and large transportation volume of my country, in some cases there will be task requirements for navigation operations in complex marine environments. In order to ensure the safety and stability of ship navigation and the smooth progress of marine operations, it is necessary to clarify the mechanism of the influence of the marine environment on the movement of large ships. The impact of the marine environment on ships is mainly through the effects of sea breeze, waves and currents. In different sea conditions, the characteristics of sea breeze, waves and currents are different, so the disturbance effect on ships is also different.

[0005] In summary, the sea breeze, waves, and currents in the marine environment influence each other and have a complex coupling relationship. Therefore, it is difficult to simulate the wind, wave, and current based on the generation mechanism. At present, most studies simulate the sea breeze, waves, and currents separately based on the mathematical models fitted by measured data. However, this method does not fully consider the mutual influence between the sea breeze, waves, and current models, and cannot realistically simulate the wind, wave, and current environment under different sea conditions. Summary of the invention

[0006] The present invention aims at the problems that the mutual influence between sea breeze, waves and current models is not considered in the current modeling process, and the wind, wave and current environment under different sea conditions cannot be truly simulated. The present invention provides a current velocity modeling method based on the wind, wave and current coupling relationship. The present invention is based on the sea breeze characteristic parameters and wave characteristic parameters under different sea conditions, and adopts 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 constructs the current velocity model. By fully considering the mutual influence between sea breeze, waves and currents, a more accurate and comprehensive current velocity model can be provided, which is of great significance for understanding and coping with complex marine environments. The present invention also relates to a current velocity modeling system based on the wind, wave and current coupling relationship.

[0007] The technical solution of the present invention is as follows:

[0008] A method for modeling ocean current velocity based on wind-wave-current coupling relationship, characterized in that it comprises the following steps:

[0009] Parameter acquisition step: acquiring sea breeze characteristic parameters and sea 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 sea 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 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 calculate 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;

[0011] The first fluctuating wind speed model and relationship establishment step: 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; and establishing an angular frequency interval according to the angular frequency and the bandwidth set based on the angular frequency, and when the angular frequency is within the angular frequency interval, constructing a relationship between the power spectrum density and the amplitude of the fluctuating wind speed;

[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, and then the fluctuating wind speed is calculated; the absolute wind speed of the sea breeze is calculated according to 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 according to the absolute wind speed of the sea breeze, and the water friction speed is calculated according to the average wind speed, air density and seawater density at sea level, and then the velocity of the wind-induced current is calculated according to the water friction speed; the velocity of the wave-induced current is calculated according to 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 statistically analyzing 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 wind-wave-current coupling relationship, characterized in that it comprises 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 which are connected in sequence.

[0018] The parameter acquisition module acquires sea breeze characteristic parameters and sea 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; the sea 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; and establishes an angular frequency interval according to the angular frequency and the bandwidth set based on the angular frequency, and when the angular frequency is within the angular frequency interval, constructs a relationship between the power spectrum density and the amplitude of the fluctuating wind speed;

[0021] The absolute wind speed calculation module obtains a second pulsating wind speed model based on the relationship between the power spectrum density and amplitude of the pulsating wind speed and the first pulsating wind speed model, and then calculates the pulsating wind speed; and calculates the absolute wind speed of the sea breeze according to the pulsating 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 according to the absolute wind speed of the sea breeze, and calculates the water flow friction speed according to the average wind speed, air density and seawater density at the sea level, and then calculates the flow velocity of the wind-induced current according to the water flow friction speed; and then calculates the flow velocity of the wave-induced current according to the significant wave height, the circular frequency, amplitude and wave number of the waves, and constructs the ocean current velocity model based on the flow velocity of the wind-induced current and the flow velocity of the wave-induced current.

[0023] Preferably, in the first pulsating wind speed model and relationship establishing module, establishing an 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 acquiring 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.

[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 the sea breeze and the characteristic parameters of the ocean waves under different sea conditions, and uses a specific calculation method to calculate the power spectrum density of the pulsating wind speed, which can effectively reveal the energy distribution of the 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 of the wind speed variation, and improve the authenticity and reliability of the model. 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 of contribution of different frequency components to the total wind speed, help identify the main disturbance sources, 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, and the influence of wind speed on the waves is fully considered, which is helpful to comprehensively evaluate the effect of wind on the wave shape of the sea surface; and the water flow friction speed is calculated according to the average wind speed, air density and seawater density at sea level, and then the flow velocity of the wind-induced current is calculated according to the water flow friction speed, which can more comprehensively describe the influence of wind on the movement of sea water; and the flow velocity of the wave-induced current is calculated according to the significant wave height, the circular frequency, amplitude and wave number of the wave, which can more comprehensively describe the influence of waves on the ocean current; the ocean current velocity model is constructed based on the flow velocity of the wind-induced current and the flow velocity of the 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 coping with 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 using 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 a current velocity model. By fully considering the mutual influence between the sea breeze, waves and currents, a more accurate and comprehensive current velocity model can be provided, which is of great significance for understanding and coping with complex marine environments. 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 in conjunction with 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 sea wave characteristic parameters under different sea conditions, sea breeze characteristic parameters include circular frequency of fluctuating wind speed, average wind speed at sea level, correlation length of wind speed fluctuation, and amplitude, angular frequency and initial phase of each simple harmonic wave of fluctuating wind speed; sea wave characteristic parameters include circular frequency, amplitude and wave number of waves. Preferably, sea wave characteristic parameters also include wavelength, and wave number is calculated according to wavelength, that is, wave number k and wavelength λ have the following relationship: k=2π / λ.

[0033] The steps for calculating the power spectral density are as follows: the average value of the circular frequency of the pulsating wind speed is calculated according to the circular frequency of the pulsating wind speed, the average wind speed at sea level and the correlation length of the wind speed fluctuations, and the power spectral density of the pulsating wind speed is calculated according to the average value of the circular frequency of the pulsating 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 pulsating 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, over what distance the wind speed fluctuations are correlated.

[0037] The first pulsating wind speed model and relationship establishment steps are as follows: the 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; 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.

[0038] Specifically, firstly, 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 pulsating 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, +∞], while in actual simulation, 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, each part is Δω long, and the frequency range of each part is when When (that is, 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, the second fluctuating wind speed model is obtained, and then the fluctuating wind speed is calculated; the absolute wind speed of the sea breeze is calculated according to 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 pulsating wind speed model, the pulsating 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 according to the absolute wind speed of the sea breeze, and the water friction speed is calculated according to the average wind speed, air density and seawater density at sea level, and then the velocity of the wind-induced current is calculated according to the water friction speed; the velocity of the wave-induced current is calculated according to 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 flow friction speed 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 sea water.

[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 Froude number is:

[0063]

[0064] The recommended height z calculation formula 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 flow 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] 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 V of the wave-induced flow is v The calculation formula is:

[0072]

[0073] Among them, 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 sea 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; the sea 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; and establishes an angular frequency interval according to the angular frequency and the bandwidth set based on the angular frequency, and when the angular frequency is within the angular frequency interval, constructs a relationship between the power spectrum density and the amplitude of the fluctuating wind speed;

[0080] The absolute wind speed calculation module obtains a second pulsating wind speed model based on the relationship between the power spectrum density and amplitude of the pulsating wind speed and the first pulsating wind speed model, and then calculates the pulsating wind speed; and calculates the absolute wind speed of the sea breeze according to the pulsating 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 according to the absolute wind speed of the sea breeze, and calculates the water flow friction speed according to the average wind speed, air density and seawater density at the sea level, and then calculates the flow velocity of the wind-induced current according to the water flow friction speed; and then calculates the flow velocity of the wave-induced current according to the significant wave height, the circular frequency, amplitude and wave number of the waves, and constructs the ocean current velocity model based on the flow velocity of the wind-induced current and the flow velocity of the wave-induced current.

[0082] Preferably, 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 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 parameters also include 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 sea breeze and sea wave under different sea conditions, a pulsating wind speed model is constructed by a specific calculation method to calculate the pulsating wind speed and the significant wave height of the sea waves, and then an ocean current velocity model is constructed. By fully considering the mutual influence between sea breeze, sea waves and sea currents, a more accurate and comprehensive ocean current velocity model can be provided, which is of great significance for understanding and coping with complex marine environments.

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

Claims

1. A method for modeling ocean current velocity based on wind-wave-current coupling, characterized in that: The following steps are involved: Parameter acquisition step: acquiring sea breeze characteristic parameters and sea 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 sea 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 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 calculate 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 step: 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; and establishing an angular frequency interval according to the angular frequency and the bandwidth set based on the angular frequency, and when the angular frequency is within the angular frequency interval, constructing a relationship between the power spectrum density and the amplitude of the fluctuating wind speed; 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, and then the fluctuating wind speed is calculated; the absolute wind speed of the sea breeze is calculated according to 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 of the ocean waves is calculated according to the absolute wind speed of the ocean breeze, and the water friction velocity is calculated according to the average wind speed, air density and seawater density at the sea level, and then the velocity of the wind-induced current is calculated according to the water friction velocity; The velocity of the wave-induced current is calculated based on the significant wave height, circular frequency of the wave, 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 method for modeling ocean current velocity 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 method for modeling ocean current velocity 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 method for modeling ocean current velocity based on wind-wave-current coupling relationship according to claim 1, 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 sea 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; the sea 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; and establishes an angular frequency interval according to the angular frequency and the bandwidth set based on the angular frequency, and when the angular frequency is within the angular frequency interval, constructs a relationship between the power spectrum density and the amplitude of the fluctuating wind speed; The absolute wind speed calculation module obtains a second pulsating wind speed model based on the relationship between the power spectrum density and amplitude of the pulsating wind speed and the first pulsating wind speed model, and then calculates the pulsating wind speed; and calculates the absolute wind speed of the sea breeze according to the pulsating wind speed and the average wind speed at sea level; The ocean current velocity model building module calculates the significant wave height of the ocean waves according to the absolute wind speed of the ocean breeze, and calculates the water flow friction velocity according to the average wind speed, air density and seawater density at the sea level, and then calculates the flow velocity of the wind-induced flow according to the water flow friction velocity; The velocity of the wave-induced current is calculated based on the significant wave height, circular frequency of the wave, 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 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.

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 acquiring 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.

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