Pile foundation scouring simulation method and device based on coupling model and electronic equipment

Abstract

The invention discloses a pile foundation scouring simulation method and device based on a coupling model and electronic equipment, and the method comprises the steps: constructing a hydrodynamic model covering an offshore wind plant area, and obtaining a computational fluid mechanics model; according to the computational fluid mechanics model and the hydrodynamic model, a coupling model of a single pile foundation area is constructed; obtaining an inlet boundary condition and an outlet boundary condition of the computational fluid mechanics model; and according to the coupling model, the inlet boundary condition and the outlet boundary condition, pile foundation group scouring is simulated, and a target simulation result is obtained. The method can improve the effectiveness and accuracy of pile foundation scouring simulation, and can be widely applied to the technical field of ocean engineering.

Description

Technical Field

[0001] The invention relates to the technical field of marine engineering, and in particular to a method, a device and an electronic device for simulating pile foundation scour based on a coupling model. Background Art

[0002] At present, most offshore wind farms are built in nearshore areas, where the hydrodynamic conditions are complex and pile foundations are prone to scouring. The operation and maintenance of offshore wind turbines play an important role in the development of offshore wind farms. The maintenance cost of offshore wind farms is very high, about 30% to 35% of the life cost. Among the high maintenance costs of offshore wind farms, the scouring maintenance of foundation piles accounts for a considerable part. Among them, soil scouring is the main cause of foundation failure. Scouring protection has three main failure modes: disintegration, edge scouring, and sinking. It can be seen that scouring failure has become an important issue for offshore wind power generation.

[0003] In view of the fact that offshore wind turbine foundation piles are prone to scouring and damage, a large number of studies have focused on flume experiments and numerical simulations based on computational fluid dynamics models (CFD). Although flume experiments can provide direct physical observations, they are costly and time-consuming, and due to factors such as scale effects and model proportions, there may be errors between the experimental results and the actual situation. On the other hand, CFD numerical simulations are low in cost, but the calculation time is long, and they can usually only be applied to small-scale regional calculations, and it is difficult to fully consider the fluid conditions in the entire offshore wind farm area. In addition, the presence of ocean currents has a significant impact on local fluid dynamics, and accurate simulation of the impact of ocean currents usually requires large-scale (about 10 kilometers) and long-term (about 3 hours) calculations. Although the size of wind turbine pile foundations is about 10 meters, they are directly affected by large-scale tidal currents in the deep sea. Therefore, it is difficult to accurately simulate the impact of actual ocean currents on the scouring of wind turbine pile foundations by relying solely on CFD models or flume experiments. Summary of the invention

[0004] In view of this, the main purpose of the embodiments of the present invention is to provide a pile foundation scour simulation method, device and electronic equipment based on a coupling model, in order to solve at least one of the problems of the prior art and improve the effectiveness and accuracy of pile foundation scour simulation.

[0005] To achieve the above object, an embodiment of the present invention provides a method for simulating pile foundation scour based on a coupling model, the method comprising the following steps:

[0006] Construct a hydrodynamic model covering the offshore wind farm area and obtain a computational fluid dynamics model;

[0007] Constructing a coupling model of a single pile foundation area according to the computational fluid dynamics model and the hydrodynamic model;

[0008] Obtaining an inlet boundary condition and an outlet boundary condition of the computational fluid dynamics model;

[0009] The scouring of the pile foundation group is simulated according to the coupling model, the inlet boundary condition and the outlet boundary condition to obtain a target simulation result.

[0010] In some embodiments, constructing a coupling model of a single pile foundation area according to the computational fluid dynamics model and the hydrodynamic model comprises the following steps:

[0011] The unstructured triangular mesh of the hydrodynamic model and the structured mesh of the computational fluid dynamics model are nested by a common boundary nesting method to obtain a nested mesh and a common boundary of the nested mesh;

[0012] Based on polynomial interpolation, construct a vertical water depth function according to the common boundary;

[0013] According to the nested grids and the vertical water depth function, the hydrodynamic model and the computational fluid dynamics model are coupled to obtain a coupled model.

[0014] In some embodiments, constructing a vertical water depth function based on the common boundary based on polynomial interpolation comprises the following steps:

[0015] Extracting vertical layer data of the hydrodynamic model at the common boundary to obtain first vertical layer data;

[0016] interpolating the sparse first vertical layer data in the hydrodynamic model into a preset grid by a linear interpolation method to generate second vertical layer data;

[0017] The second vertical layer data is fitted by a polynomial fitting method to obtain the vertical water depth function.

[0018] In some embodiments, the vertical water depth function is expressed as:

[0019] u(z)=a n z n +a n-1 z n-1 +…+a1z+a0

[0020] Where u(z) represents the vertical water depth function; a n ,a n-1 ,…,a1,a0 represent polynomial coefficients; z n ,z n-1 ,…,z represents the water depth; n represents the polynomial order.

[0021] In some embodiments, coupling the hydrodynamic model with the computational fluid dynamics model according to the nested grid and the vertical water depth function to obtain a coupled model comprises the following steps:

[0022] According to the nested grid, the vertical water depth function is input into the computational fluid dynamics model to form the coupled model.

[0023] In some embodiments, obtaining the inlet boundary condition and the outlet boundary condition of the computational fluid dynamics model comprises the following steps:

[0024] Acquire a flow direction vector of a target fluid entering a structured grid of the computational fluid dynamics model;

[0025] Obtaining a boundary normal vector of an unstructured triangular mesh of the hydrodynamic model;

[0026] Obtaining the dot product of the flow direction vector and the boundary normal vector;

[0027] The inlet boundary condition and the outlet boundary condition are obtained according to the dot product.

[0028] In some embodiments, obtaining the inlet boundary condition and the outlet boundary condition according to the dot product comprises the following steps:

[0029] The unstructured triangular mesh of the hydrodynamic model and the structured mesh of the computational fluid dynamics model are nested by a common boundary nesting method to obtain a nested mesh and a common boundary of the nested mesh;

[0030] When the dot product is less than zero, using the common boundary of the nested grids as the inlet boundary condition;

[0031] When the dot product is greater than or equal to zero, the common boundary of the nested grids is used as an exit boundary condition.

[0032] To achieve the above object, another aspect of an embodiment of the present invention provides a pile foundation scour simulation device based on a coupling model, the device comprising:

[0033] The first module is used to build a hydrodynamic model covering the offshore wind farm area and obtain a computational fluid dynamics model;

[0034] The second module is used to construct a coupling model of a single pile foundation area according to the computational fluid dynamics model and the hydrodynamic model;

[0035] The third module is used to obtain the inlet boundary conditions and the outlet boundary conditions of the computational fluid dynamics model;

[0036] The fourth module is used to simulate the scouring of the pile foundation group according to the coupling model, the inlet boundary condition and the outlet boundary condition to obtain the target simulation result.

[0037] To achieve the above purpose, another aspect of an embodiment of the present invention provides an electronic device, which includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements the aforementioned method for simulating pile foundation scour based on a coupling model.

[0038] To achieve the above purpose, another aspect of an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the aforementioned method for simulating pile foundation scour based on a coupling model is implemented.

[0039] To achieve the above object, another aspect of an embodiment of the present invention provides a computer program product or a computer program, the computer program product or the computer program includes computer instructions, and the computer instructions are stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the aforementioned method for simulating pile foundation scour based on a coupling model.

[0040] The embodiments of the present invention include at least the following beneficial effects: The present invention provides a method, device and electronic equipment for simulating pile foundation scour based on a coupling model. The scheme constructs a hydrodynamic model covering the offshore wind farm area and obtains a computational fluid dynamics model; constructs a coupling model of a single pile foundation area based on the computational fluid dynamics model and the hydrodynamic model; obtains the inlet boundary conditions and the outlet boundary conditions of the computational fluid dynamics model; simulates the scour of the pile foundation group based on the coupling model, the inlet boundary conditions and the outlet boundary conditions to obtain the target simulation results, which can improve the effectiveness and accuracy of the pile foundation scour simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 is a flow chart of a pile foundation scour simulation method based on a coupling model provided by an embodiment of the present invention;

[0043] Figure 2is a schematic diagram of a coupling model technology framework provided by an embodiment of the present invention;

[0044] Figure 3 is a schematic diagram of co-boundary nesting of an unstructured triangular FVCOM grid and a structured OpenFOAM grid provided by an embodiment of the present invention;

[0045] Figure 4 is a schematic diagram of a data transmission method provided by an embodiment of the present invention;

[0046] Figure 5 It is a schematic diagram comparing the vertical flow velocity distribution of the FVCOM and FVCOM-OpenFOAM nested interfaces at different time steps provided by an embodiment of the present invention;

[0047] Figure 6 It is a schematic diagram of the unstructured grid, the location of tide gauge stations and the observation points used for verification of the FVCOM model of the Pearl River Estuary and adjacent areas provided by an embodiment of the present invention;

[0048] Figure 7 It is a schematic diagram of comparison between the observed tide levels of three tide measuring stations and the model data of the simulated tide levels provided by an embodiment of the present invention;

[0049] Figure 8 is a schematic diagram of model data comparison between observation results and simulation results provided by an embodiment of the present invention;

[0050] Fig. 9 It is a velocity streamline diagram of the FVCOM-OpenFOAM coupling result at different time steps provided by an embodiment of the present invention;

[0051] Fig.10 It is a schematic diagram of the results of the ratio of scour depth to single pile diameter (S / D) at different time steps provided by an embodiment of the present invention;

[0052] Fig.11 It is a schematic diagram of the hardware structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present invention, and they are only examples of devices and methods consistent with some aspects of the embodiments of the present invention as detailed in the attached claims.

[0054] It should be noted that, although the functional modules are divided in the system schematic diagram and the logical order is shown in the flow chart, in some cases, the steps shown or described may be performed in a different order than the module division in the system or the flow chart. The terms "first / S100" and "second / S200" in the specification and claims and the above-mentioned drawings may be used to describe various concepts in this article, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiment of the present invention, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determination".

[0055] The terms "at least one", "multiple", "each", "any", etc. used in the present invention, at least one includes one, two or more, multiple includes two or more, each refers to each of the corresponding multiple, and any refers to any one of the multiple.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein are only for the purpose of describing the embodiments of the present invention and are not intended to limit the present invention.

[0057] Before describing the embodiments of the present invention in detail, some nouns and terms involved in the embodiments of the present invention are first described. The nouns and terms involved in the embodiments of the present invention are subject to the following explanations.

[0058] Computational Fluid Dynamics (CFD): is a scientific method that uses numerical analysis and algorithms to simulate and analyze fluid flow. CFD models predict the behavior of fluids under different conditions by solving basic equations of fluid dynamics (such as the Navier-Stokes equations).

[0059] Geophysical Fluid Dynamics (GFD) is a scientific model specifically used to simulate and study fluid dynamics processes in geophysical environments. The GFD model mainly studies the movement of fluids in the atmosphere, oceans, and the interior of the Earth.

[0060] FVCOM: The full name is "Finite-Volume Community Ocean Model". It uses unstructured grids and is an ocean numerical model based on the finite volume method. It is mainly used to simulate and predict physical processes in the ocean and coastal areas, including tides, waves, ocean currents, temperature, salinity distribution, etc. FVCOM can be considered as a specific model and tool for ocean dynamic simulation in the field of GFD. In short, GFD provides a theoretical framework and scientific basis, and FVCOM is a specific model developed under this framework for actual ocean simulation.

[0061] OpenFOAM: The full name is "Open Source Field Operation and Manipulation", which is an open source computational fluid dynamics (CFD) software package that is widely used to simulate and analyze complex physical phenomena such as fluid flow, heat transfer, mass transfer, turbulence, multiphase flow and chemical reactions. It is written in C++ and provides a flexible and extensible platform that allows users to customize solvers, physical models and post-processing tools.

[0062] Pile foundation scour: refers to the phenomenon that the soil or sediment around the water body is eroded, transported and washed away from the vicinity of the pile foundation due to the impact and disturbance of the water flow in a water flow environment. It usually occurs around the foundation of underwater structures (such as bridges, docks or offshore wind power pile foundations). Changes in water flow velocity lead to increased local pressure and shear stress, which in turn causes the loss of base materials. This scour phenomenon may weaken the stability of the pile foundation, thereby affecting the safety and durability of the structure. Therefore, the prediction and prevention of pile foundation scour is an important issue in the design and maintenance of hydraulic structures.

[0063] like Figure 1 As shown, the embodiment of the present invention further provides a pile foundation scour simulation method based on a coupling model, which may include but is not limited to steps S100 to S400:

[0064] Step S100, constructing a hydrodynamic model covering the offshore wind farm area and obtaining a computational fluid dynamics model;

[0065] Step S200, constructing a coupling model of a single pile foundation area according to the computational fluid dynamics model and the hydrodynamic model;

[0066] Step S300, obtaining an inlet boundary condition and an outlet boundary condition of the computational fluid dynamics model;

[0067] Step S400, simulating the scouring of the pile foundation group according to the coupling model, the inlet boundary condition and the outlet boundary condition to obtain a target simulation result.

[0068] In some embodiments, geophysical fluid dynamics (GFD) is successful and effective in simulating large-scale (1km to 10,000km) ocean currents and waves. Computational fluid dynamics (CFD) can accurately depict the flow characteristics around structures when simulating small-scale (1m to 1km) fluid motion. Figure 2 As shown, by combining the advantages of the GFD model in large-scale ocean current simulation and the accuracy of the CFD model in small-scale water flow structure analysis, a GFD+CFD coupling model is constructed, which can achieve comprehensive simulation of cross-scale and multi-physical processes. Based on geophysical fluid mechanics and computational fluid dynamics, the embodiment of the present invention constructs an FVCOM-OpenFOAM coupling model through a hydrodynamic model (FVCOM) and a computational fluid dynamics model (OpenFOAM), which can be used to simulate the scouring phenomenon of offshore structures.

[0069] In some embodiments, Figure 2 As shown, a FVCOM-OpenFOAM coupling model of a single wind turbine pile foundation area is constructed. Since there are significant differences in scale between the GFD model and the CFD model, the consistency of cross-scale mass and energy transfer must be carefully considered when coupling the two models. Therefore, the embodiment of the present invention adopts a common boundary nesting method to achieve accurate transfer of mass and energy. First, the flow field of the entire offshore wind farm area is simulated in FVCOM, and then one of the pile foundations is selected. Combined with the data transmission method, the background flow field simulated by FVCOM is input into OpenFOAM for coupling to perform scour simulation of a single structure. The scour simulation of a group of structures can be performed using the FVCOM-OpenFOAM coupling model.

[0070] In step S100 of some embodiments, a FVCOM hydrodynamic model covering the offshore wind farm area is constructed. FVCOM uses an unstructured grid so that the hydrodynamic model can carefully depict the shape of the wind turbine pile foundation. By comparing and verifying the simulation results of the wind field, tide level, salinity, flow velocity, etc. of the FVCOM hydrodynamic model with the measured data, a solid foundation can be provided for the reliability of the model. The open source computational fluid dynamics (CFD) software package OpenFOAM is obtained as a computational fluid dynamics model.

[0071] In some embodiments, step S200 may include but is not limited to steps S210 to S230:

[0072] Step S210, nesting the unstructured triangular mesh of the hydrodynamic model and the structured mesh of the computational fluid dynamics model using a common boundary nesting method to obtain a nested mesh and a common boundary of the nested mesh;

[0073] Step S220, constructing a vertical water depth function based on the common boundary based on polynomial interpolation;

[0074] Step S230: performing a coupling operation on the hydrodynamic model and the computational fluid dynamics model according to the nested grid and the vertical water depth function to obtain a coupled model.

[0075] In step S210 of some embodiments, the unstructured triangular mesh of FVCOM and the structured mesh of OpenFOAM are nested by a common boundary nesting method, so that the unstructured triangular mesh of FVCOM and the structured mesh of OpenFOAM completely overlap at the specified boundary. Figure 3 , Figure 3 Part (b) in the figure is the structured grid of OpenFOAM. The structured grid is designed radially with the pile as the center point. R0 represents the radius of the single pile. The nested triangular grid also includes a circular inner boundary (such as Figure 3 The bold red triangle mesh in part (a) covers one to three rows of the structure mesh, depending on the resolution. Figure 3 All the red mesh areas in part (a) are the unstructured triangular meshes of FVCOM around the pile foundation. The bold red triangular meshes represent the common boundary of the common boundary nesting area. The ring determined by the distance between the two black points P0 and P1 is the location of the common boundary nesting interface and the internal domain. Through the common boundary nesting method, the result variables can be directly received from the FVCOM domain to the OpenFOAM domain.

[0076] In FVCOM, the water column is discretized into multiple vertical layers, that is, the entire water body from the sea surface to the seabed is discretized into multiple vertical layers in the vertical direction, which can be evenly or unevenly distributed. For two-phase flow simulation, OpenFOAM provides a higher vertical resolution. In order to ensure the stability and reliability of model coupling, a finer vertical resolution is required near the interface between the water column and the seabed. However, due to the difference in vertical discretization between FVCOM and OpenFOAM, directly matching the vertical resolution of the two models may lead to scale mismatch problems, especially when dealing with the transition from large scale to small scale, and lead to a decrease in computational efficiency, especially when dealing with large amounts of data and complex flow conditions. It may also lead to the loss or over-simplification of certain physical phenomena, thereby affecting the accuracy and efficiency of subsequent simulations.

[0077] In view of this, in step S220 of some embodiments, a data transmission method including a linear interpolation method and a polynomial fitting method is adopted. Step S220 may include but is not limited to steps S221 to S223:

[0078] Step S221, extracting vertical layer data of the hydrodynamic model at the common boundary to obtain first vertical layer data;

[0079] Step S222, interpolating the sparse first vertical layer data in the hydrodynamic model into a preset grid by a linear interpolation method to generate second vertical layer data;

[0080] Step S223: fitting the second vertical layer data by a polynomial fitting method to obtain the vertical water depth function.

[0081] In some embodiments, the variables (including flow velocity, salinity, etc.) and depth information of each vertical layer of the grid at the common boundary are extracted from the simulation results of the FVCOM model (i.e., the simulation results obtained by simulating the hydrodynamic process of the pile foundation group through the FVCOM model, wherein the simulation results may include but are not limited to wind field, tidal salinity, and flow velocity). Since the vertical resolutions of FVCOM and OpenFOAM do not match, the vertical distribution of the variables extracted from the simulation results of the above-mentioned FVCOM model is expressed as a display function of the vertical water depth (vertical water depth function f=u(z)) using a polynomial fitting method, and the vertical water depth function is input into OpenFOAM, which can flexibly and effectively ensure the consistency and stability of data transmission between models. Given that FVCOM usually uses sigma coordinates to divide the vertical into 10 to 20 layers (such as vertical depth function f=u(z)) in the vertical direction. Figure 4 The vertical sigma distribution shown in Figure 1 is different from the vertical sigma distribution shown in Figure 2. However, when simulating pile foundation scour in OpenFOAM, the model grid in the vertical direction needs to be encrypted at the seabed surface, resulting in a larger number of vertical layers than that of FVCOM. In order to ensure sufficient data points during polynomial fitting, before polynomial fitting, the embodiment of the present invention uses linear interpolation to interpolate the relatively sparse vertical layer data (i.e., the vertical distribution of variables) in FVCOM onto a high-density, vertically uniform preset grid (e.g., Figure 4 The high-density uniform vertical distribution shown in Figure 2 is shown in Figure 2). Through the linear interpolation method, more data points can be generated, thereby improving the accuracy of polynomial fitting. Among them, the data point refers to the data of the variable at each vertical layer, such as Figure 4 As shown, if there are 10 sigma layers, there are 10 data points. By generating more vertical layers and using linear interpolation, the data points of the original FVCOM can be increased. Then, the polynomial fitting toolkit in Python (such as numpy.polyfit function) is used to fit the vertical velocity distribution data of FVCOM (i.e., the distribution of velocity in the vertical direction) as a function of water depth. The expression of the vertical water depth function is as follows:

[0082] u(z)=a n zn +a n-1 z n-1 +…+a1z+a0

[0083] Where u(z) represents the vertical water depth function; a n ,a n-1 ,…,a1,a0 represent polynomial coefficients; z n ,z n-1 ,…,z represents the water depth; n represents the polynomial order.

[0084] By fitting the vertical water depth function with a high-order polynomial, we can get Figure 4 The non-uniform vertical distribution shown in FIG. 1 may be optionally verified by experiments to use a fifth-order or higher-order polynomial fit for complex vertical flow profiles. The polynomial fitting method can be used to convert the vertical velocity distribution data of FVCOM into a vertical water depth function that can be directly input into OpenFOAM, which can maintain data consistency and adapt to different vertical grid resolutions (effects such as Figure 5 The problem of inconsistent vertical resolution between FVCOM and OpenFOAM can be solved by linear interpolation and polynomial fitting, thus ensuring the accuracy and stability of the two in the coupling process.

[0085] In some embodiments, step S230 may include but is not limited to step S231:

[0086] Step S231: input the vertical water depth function into the computational fluid dynamics model according to the nested grid to form the coupling model.

[0087] In some embodiments, the vertical water depth function is input into the computational fluid dynamics model according to the nested grid, ensuring the accuracy and stability of both the hydrodynamic model and the computational fluid dynamics model during the coupling process, thereby forming a FVCOM-OpenFOAM coupling model that couples the hydrodynamic model with the computational fluid dynamics model.

[0088] In real ocean scenarios, the direction and speed of fluid motion change rapidly, such as rotating tidal currents. Therefore, it is critical to determine the direction of flow entering the OpenFOAM domain. At each time step, a direction check is performed to ensure that the FVCOM variables at the outer edge of the boundary triangle (i.e., the variables of the mesh at each vertical layer at the common boundary extracted from the simulation results of the FVCOM model) enter the OpenFOAM domain.

[0089] In view of this, in step S300 of some embodiments, various boundary conditions are set and relevant parameters are initialized. Step S300 may include but is not limited to steps S310 to S340:

[0090] Step S310, obtaining a flow direction vector of the target fluid entering the structured grid of the computational fluid dynamics model;

[0091] Step S320, obtaining the boundary normal vector of the unstructured triangular mesh of the hydrodynamic model;

[0092] Step S330, obtaining the dot product of the flow direction vector and the boundary normal vector;

[0093] Step S340: Obtain the inlet boundary condition and the outlet boundary condition according to the dot product.

[0094] In some embodiments, in step S310 to step S330, the flow direction vector of the target fluid entering the structured grid of the computational fluid dynamics model is obtained. and the boundary normal vectors of the unstructured triangular mesh of the hydrodynamic model Calculate the flow vector and the boundary normal vector The dot product between

[0095] In some embodiments, step S340 may include but is not limited to steps S341 to S343:

[0096] Step S341, nesting the unstructured triangular mesh of the hydrodynamic model and the structured mesh of the computational fluid dynamics model by a common boundary nesting method to obtain a nested mesh and a common boundary of the nested mesh;

[0097] Step S342, when the dot product is less than zero, taking the common boundary of the nested grids as the entry boundary condition;

[0098] Step S343: when the dot product is greater than or equal to zero, the common boundary of the nested grids is used as an exit boundary condition.

[0099] In steps S342 to S343 of some embodiments, if the dot product is less than zero, indicating that FVCOM is transferring mass or energy to the inner domain, and the common boundary of the nested meshes is treated as the inlet boundary condition of the OpenFOAM model. If it is greater than or equal to zero, the common boundary of the nested grids is set to the outlet boundary condition and the velocity boundary condition is set to zero gradient.

[0100] In some embodiments, since the pressure is a motion pressure and the model does not include a thermodynamic simulation, the absolute value of the pressure is irrelevant to the model, and for convenience, the pressure value of the internal field is initialized to a uniform 0. In order to keep the pressure gradient between the internal field and the boundary unchanged, the boundary pressure is also initialized to a uniform 0.

[0101] In some embodiments, in OpenFOAM, a fixed velocity and zero gradient pressure are specified at the inlet, and a zero gradient velocity and a fixed value pressure are specified at the outlet. This boundary can effectively prevent fluid backflow, thereby ensuring the stability of the model. Both FVCOM and OpenFOAM models are initialized with zero velocity, and the coupled model gradually transitions to real-world conditions within the model transition time specified in FVCOM.

[0102] In step S400 of some embodiments, the scour of the pile foundation group is simulated according to the coupling model, the inlet boundary condition and the outlet boundary condition to obtain a target simulation result.

[0103] In some embodiments, Figure 2 As shown in the figure, based on geophysical fluid mechanics and computational fluid dynamics, a FVCOM-OpenFOAM coupling model is constructed. Through this coupling model, combined with the inlet boundary conditions and the outlet boundary conditions, the scour simulation of the pile foundation group can be performed to obtain the simulation results. For example, the simulation results may include but are not limited to the scour pit shape and depth changes, flow field changes, scour depth time-varying curves, etc.

[0104] In some embodiments, the coupling method used for a single wind turbine pile foundation can be extended to the entire offshore wind farm area. In the offshore wind farm area, for wind turbine pile foundations of the same type, the shape and resolution of the common boundary nested grids can be the same. However, they should be placed in different geographical locations with different water depths and boundary fluxes to take into account the individual characteristics of each wind turbine pile foundation. This method can use multiple nested grids to simulate the entire wind farm sea area. If the geometry of the wind turbine pile foundation has not changed, there is no need to regenerate the nested grids.

[0105] An offshore wind farm in Yangjiang, Guangdong Province, was used as an example to simulate pile foundation scour. The main hydrodynamic process in the Yangjiang wind farm area is the irregular semi-diurnal tide affected by the low-salinity diluted water of the Pearl River. This indicates that the wind farm is affected by both periodic tides and unidirectional longshore currents, especially in winter. In addition, the region frequently encounters tropical cyclones during the summer monsoon season, resulting in strong waves and currents. These dynamic characteristics make Yangjiang an ideal research area for conducting GFD-CFD coupling experiments.

[0106] Firstly, a FVCOM hydrodynamic model covering the entire offshore wind farm area was constructed. Figure 6As shown in the figure, the unstructured grid feature of FVCOM enables the location of each wind turbine pile to be accurately depicted in the model. As of 2021, the wind farm has a total of 256 wind turbines with a total installed capacity of 300 MW. The main foundation type of the OWT in the wind farm is a single pile with a diameter of 10 meters. The wind turbine pile foundation is mainly arranged in a strip shape and in the northwest direction in the wind farm. The average depth of the wind farm is about 30 meters.

[0107] like Figure 6 As shown, Figure 6 Part (a) shows the unstructured grid of the FVCOM model in the Pearl River Estuary and adjacent areas, the locations of tide gauges, and the observation points used for verification. Figure 6 Part (b) shows an enlarged view of the Yangjiang offshore wind farm area. Figure 6 Part (c) shows the overlap of a single wind turbine and the OpenFOAM structure grid. Figure 6 In part (a), the black dots indicate the locations of the measuring points and stations, and the black text indicates the names of the corresponding stations. Figure 6 In part (c), all red grids represent FVCOM grids, blue lines represent OpenFOAM grids, and bold red grids represent nested common boundaries.

[0108] refer to Figure 6 In part (a), the Yangjiang offshore wind farm and its surrounding coast and the Pearl River Estuary area are spatially discretized using the FVCOM unstructured grid. Figure 6 In the red grid of part (c), the resolution near the wind turbine pile foundation (about 10 meters in diameter) is set to 2.5 meters. At the lateral open boundary, the resolution is gradually extended to 30 kilometers. In order to implement the common boundary nesting method throughout the wind farm, each single pile foundation shares the same grid structure within the common boundary area with a radius of 100 meters, which means that all triangular nodes and cells of all single piles have the same shape and triangle connectivity (such as Figure 6 (c) in the wind farm). Therefore, any wind pile foundation within the wind farm only requires a single type of triangle nested boundary and internal structure mesh in OpenFOAM. Geographic coordinates and water depth measurements can be specified separately according to the respective wind pile foundation conditions (such as water depth and flow velocity).

[0109] In the vertical direction of FVCOM, the water column is discretized into ten equally spaced sigma layers. The open boundary conditions include eight important astronomical tidal components, including four diurnal tides (K1, O1, P1, and Q1) and four semidiurnal tides (M2, S2, N2, and K2), which are obtained from the TPXO 8 dataset (Egbert and Erofeeva, 2002). At the upstream river boundary, the Dongjiang, Xijiang, Beijiang, Zengjiang, Tanjiang, and Liuxi Rivers ( Figure 6(a) Daily discharge of six major rivers. Atmospheric conditions including wind, precipitation and heat flux are from the ERA5 dataset provided by the European Centre for Medium-Range Weather Forecasts, which has a spatial resolution of 0.25° and a temporal resolution of 3 h. Temperature and salinity are initialized using the output of the Global Ocean Forecast System (GOFS) 3.1 dataset on the GLBy0.08 grid of the Global Hybrid Coordinate Ocean Model (HYCOM). The time steps of the outer and inner models of the FVCOM model are 0.5 and 2.5 s, respectively.

[0110] In order to verify the ability of FVCOM to accurately reflect the hydrodynamics of the Yangjiang offshore wind farm area and verify the reliability and accuracy of the FVCOM model, the measured data in December 2020 were compared with the simulation results of FVCOM. Figure 6 In part (a) of the paper, the simulated tides generated by FVCOM are verified using tide gauge data from the Pearl River Estuary. The results show that FVCOM accurately resolves the tides in the Pearl River Estuary and the surrounding areas (e.g. Figure 7 As shown, Figure 7 The black dots in parts (a), (b) and (c) are observed tide levels, and the red lines are simulated tide levels), and the root mean square error (RMSE) is 0.13 meters. Figure 6 In part (a) of Figure 1, surface and bottom fluid velocities, directions, and surface salinity collected from two measurement points around the wind farm are used to verify fluid motion. Figure 8 As shown in the figure, the simulation results of the model show that the root mean square error values ​​of the surface and bottom flow velocities are 0.09m / s and 0.07m / s respectively, the root mean square error values ​​of the surface and bottom flow directions are 28.90° and 50.64° respectively, and the root mean square error value of salinity is 0.75PSU. Figure 8 The black dots in the figure are observation results, and the red lines are simulation results. Figure 8 Parts (a), (b), (c), (d) and (e) describe the surface velocity, surface flow direction, surface salinity and bottom flow velocity, bottom flow direction at site 1, respectively. However, in the context of weak flow, the model overestimates the flow velocity, mainly in the dry season, which also leads to an increase in the error of the bottom flow direction. Both observational and model results show that astronomical tides and longshore currents have a weak impact on salinity changes. In terms of surface salinity verification, the model results are almost completely consistent with the observational data. These comparisons show that FVCOM captures the main hydrodynamic characteristics around the Yangjiang offshore wind farm.

[0111] The wind turbine pile foundation located in the center of the wind farm is affected by the wake of the surrounding pile foundations and is representative of the pile foundation scour simulation of the entire wind farm. Therefore, the wind turbine pile foundation located in the center is selected for coupled scour simulation. Fig. 9As shown in parts (a)-(b), the model initially flows westward, and by t = 1.0 hours, the flow velocity gradually increases to a quasi-steady state. The results show that the vertical profile is obvious under the drive of FVCOM, with surface velocity of 0.5 m / s and bottom velocity of 0.15-0.2 m / s. Under these realistic conditions, the coupled modeling approach effectively captures the formation of vortex streets and horseshoe vortices induced by the water flow around the annular monopile. Fig. 9 As shown in parts (b)-(f) of the figure, the water flow around the monopile exhibits rapid and dramatic fluctuations throughout the tidal cycle as the magnitude and direction of the tidal flow change. These modeling results provide insight into the dynamic nature of tidal flow patterns. It was observed that the tidal flow initially rotated in a counterclockwise direction during t=1h to t=7h, and then transitioned to a clockwise direction during t=7h to t=13h. The shift in flow direction was approximately 60 degrees, accompanied by a change in amplitude. This behavior can be attributed to the fact that the offshore wind farm is located on the west side of the Pearl River Estuary and experiences a continuous westward longshore current throughout the year. Therefore, the tidal rotation in this area is constrained by the prevailing longshore current.

[0112] Under the influence of realistic ocean currents driven by astronomical tides and coastal currents, the interaction between ocean currents and bottom mud around the monopile foundation presents a highly complex response (e.g. Fig.10 (a)-(f) shown). Due to the inhomogeneity of boundary currents and intra-domain currents, the scouring pattern also shows an uneven distribution. Nevertheless, the results still show that under the action of the westward tidal current, a clear horseshoe-shaped vortex is formed during the slope time, resulting in a scouring pit (e.g., about 8% of the single pile diameter (about 0.8 m)) after one hour of scouring. Fig.10 Over time, the scour depth increases to 8.5% of the pile diameter (about 0.85 m) (see Figure 2). Fig.10 As the tide rotates and the flow rate changes, the scouring pattern will also fluctuate rapidly, characterized by scouring occurring mainly on the northeast side of the pile and deposition occurring on the southwest side. At the end of a tidal cycle (T = 13h), sand ripples will form (e.g. Fig.10 As shown in part (f) of the figure, the length of these sand ripples ranges from 0.8 to 1 times the pile diameter.

[0113] The embodiment of the present invention further provides a pile foundation scour simulation device based on a coupling model, which can implement the above-mentioned pile foundation scour simulation method based on a coupling model. The device includes:

[0114] The first module is used to build a hydrodynamic model covering the offshore wind farm area and obtain a computational fluid dynamics model;

[0115] The second module is used to construct a coupling model of a single pile foundation area according to the computational fluid dynamics model and the hydrodynamic model;

[0116] The third module is used to obtain the inlet boundary conditions and the outlet boundary conditions of the computational fluid dynamics model;

[0117] The fourth module is used to simulate the scouring of the pile foundation group according to the coupling model, the inlet boundary condition and the outlet boundary condition to obtain the target simulation result.

[0118] It can be understood that the contents of the above method embodiments are all applicable to the present device embodiments, the functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0119] The embodiment of the present invention further provides an electronic device, which includes a processor and a memory, wherein the memory stores a computer program, and when the processor executes the computer program, the above-mentioned method for simulating pile foundation scour based on a coupling model is implemented. The electronic device can be any intelligent terminal including a tablet computer, a vehicle-mounted computer, etc.

[0120] It can be understood that the contents of the above method embodiments are all applicable to the present device embodiments, the functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0121] refer to Fig.11 , Fig.11 The hardware structure of an electronic device of another embodiment is illustrated, and the electronic device includes:

[0122] The processor 501 may be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present invention.

[0123] The memory 502 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 502 can store an operating system and other application programs. When the technical solution provided in the embodiment of this specification is implemented by software or firmware, the relevant program code is stored in the memory 502, and the processor 501 calls and executes a method for simulating pile foundation scour based on a coupling model in an embodiment of the present invention;

[0124] Input / output interface 503, used to implement information input and output;

[0125] Communication interface 504, used to realize communication interaction between the device and other devices, which can be realized through wired mode (such as USB, network cable, etc.) or wireless mode (such as mobile network, WI FI, Bluetooth, etc.);

[0126] A bus 505 that transmits information between the various components of the device (e.g., the processor 501, the memory 502, the input / output interface 503, and the communication interface 504);

[0127] The processor 501 , the memory 502 , the input / output interface 503 and the communication interface 504 are connected to each other in communication within the device via a bus 505 .

[0128] An embodiment of the present invention further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the method for simulating pile foundation scour based on a coupling model is implemented.

[0129] It can be understood that the contents of the above method embodiments are all applicable to the present storage medium embodiments, the functions specifically implemented by the present storage medium embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0130] The embodiment of the present invention also provides a computer program product or a computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the aforementioned method for simulating pile foundation scour based on a coupling model.

[0131] In summary, the method, device and electronic device for simulating pile foundation scour based on a coupling model according to an embodiment of the present invention have the following advantages:

[0132] 1. The FVCOM ocean model combines the advantages of existing ocean finite difference models and finite element models, and can effectively and accurately simulate the hydrodynamic processes in shallow seas; OpenFOAM contains a variety of solvers, which can select appropriate turbulence models according to specific circumstances, thereby dealing with complex turbulence and sediment transport problems.

[0133] 2. The embodiment of the present invention proposes a common boundary nesting method to ensure the consistency of cross-scale mass and energy transfer from FVCOM to OpenFOAM. By adopting boundary nesting, the FVCOM-OpenFOAM coupling model not only considers the large-scale ocean motion process caused by wind, tides and circulation, but also limits the use of the CFD model to the area around a single structure, thereby optimizing the computational efficiency.

[0134] 3. The embodiment of the present invention implements a data transmission method from FVCOM to OpenFOAM to ensure the effective transmission and consistency of data between models.

[0135] 4. The embodiment of the present invention constructs a FVCOM-OpenFOAM coupling model based on the geophysical fluid dynamics model (GFD) and the computational fluid dynamics model (CFD), which can be used to simulate the scouring phenomenon of offshore structures under actual tidal conditions. The offshore hydrodynamic process is accurately simulated by FVCOM, and the common boundary nesting method and data transmission method proposed in the present invention are used to pass the simulation results of FVCOM as input conditions to OpenFOAM, so as to perform scouring simulation of offshore structures under actual tidal conditions.

[0136] 5. In order to more accurately simulate the scouring conditions of pile foundations under actual engineering conditions, the embodiment of the present invention introduces the actual offshore tidal environment into the model, making the simulation results closer to reality and directly applicable to actual engineering. This coupling model provides important theoretical support and reference basis for the construction and maintenance of offshore structures in the future, and is of great significance in the evaluation before marine engineering construction and prevention after construction.

[0137] In some selectable embodiments, the function / operation mentioned in the block diagram may not occur in the order mentioned in the operation diagram. For example, depending on the function / operation involved, the two boxes shown in succession can actually be executed substantially simultaneously or the boxes can sometimes be executed in reverse order. In addition, the embodiment presented and described in the flow chart of the present invention is provided by way of example, for the purpose of providing a more comprehensive understanding of technology. The disclosed method is not limited to the operation and logic flow presented herein. Selectable embodiments are expected, wherein the order of various operations is changed and the sub-operation of a part for which is described as a larger operation is performed independently.

[0138] In addition, although the present invention is described in the context of functional modules, it should be understood that, unless otherwise specified, one or more of the functions and / or features described may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in separate physical devices or software modules. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the present invention. More specifically, in view of the properties, functions, and internal relationships of the various functional modules in the device disclosed herein, the actual implementation of the module will be understood within the conventional skills of the engineer. Therefore, those skilled in the art can implement the present invention set forth in the claims without excessive experimentation using ordinary techniques. It is also understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of the present invention, which is determined by the full scope of the appended claims and their equivalents.

[0139] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0140] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0141] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0142] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0143] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0144] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

[0145] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the described embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A pile foundation scour simulation method based on a coupling model, characterized in that: The following steps are involved: Construct a hydrodynamic model covering the offshore wind farm area and obtain a computational fluid dynamics model; Constructing a coupling model of a single pile foundation area according to the computational fluid dynamics model and the hydrodynamic model; Obtaining an inlet boundary condition and an outlet boundary condition of the computational fluid dynamics model; According to the coupling model, the inlet boundary condition and the outlet boundary condition, the scouring of the pile foundation group is simulated to obtain the target simulation result.

2. A pile foundation scour simulation method based on a coupling model according to claim 1, characterized in that: The step of constructing a coupling model of a single pile foundation area according to the computational fluid dynamics model and the hydrodynamic model comprises the following steps: The unstructured triangular mesh of the hydrodynamic model and the structured mesh of the computational fluid dynamics model are nested by a common boundary nesting method to obtain a nested mesh and a common boundary of the nested mesh; Based on polynomial interpolation, construct a vertical water depth function according to the common boundary; According to the nested grids and the vertical water depth function, the hydrodynamic model and the computational fluid dynamics model are coupled to obtain a coupled model.

3. A pile foundation scour simulation method based on a coupling model according to claim 2, characterized in that: The method of constructing a vertical water depth function based on the common boundary based on polynomial interpolation includes the following steps: Extracting vertical layer data of the hydrodynamic model at the common boundary to obtain first vertical layer data; interpolating the sparse first vertical layer data in the hydrodynamic model into a preset grid by a linear interpolation method to generate second vertical layer data; The second vertical layer data is fitted by a polynomial fitting method to obtain the vertical water depth function.

4. A method for simulating pile foundation scour based on a coupling model according to claim 3, characterized in that: The expression of the vertical water depth function is: u(z)=a n z n +a n-1 z n-1 +…+a1z+a0 Where u(z) represents the vertical water depth function; a n ,a n-1 ,…,a1,a0 represent polynomial coefficients; z n ,z n-1 ,…,z represents the water depth; n represents the polynomial order.

5. The method for simulating pile foundation scour based on a coupling model according to claim 2, characterized in that: The coupling operation is performed on the hydrodynamic model and the computational fluid dynamics model according to the nested grid and the vertical water depth function to obtain a coupled model, comprising the following steps: According to the nested grid, the vertical water depth function is input into the computational fluid dynamics model to form the coupled model.

6. A pile foundation scour simulation method based on a coupling model according to claim 1, characterized in that: The step of obtaining the inlet boundary condition and the outlet boundary condition of the computational fluid dynamics model comprises the following steps: Acquire a flow direction vector of a target fluid entering a structured grid of the computational fluid dynamics model; Obtaining a boundary normal vector of an unstructured triangular mesh of the hydrodynamic model; Obtaining the dot product of the flow direction vector and the boundary normal vector; The inlet boundary condition and the outlet boundary condition are obtained according to the dot product.

7. A method for simulating pile foundation scour based on a coupling model according to claim 6, characterized in that: The step of obtaining the inlet boundary condition and the outlet boundary condition according to the dot product comprises the following steps: The unstructured triangular mesh of the hydrodynamic model and the structured mesh of the computational fluid dynamics model are nested by a common boundary nesting method to obtain a nested mesh and a common boundary of the nested mesh; When the dot product is less than zero, using the common boundary of the nested grids as the inlet boundary condition; When the dot product is greater than or equal to zero, the common boundary of the nested grids is used as an exit boundary condition.

8. A pile foundation scour simulation device based on a coupling model, characterized in that: include: The first module is used to build a hydrodynamic model covering the offshore wind farm area and obtain a computational fluid dynamics model; The second module is used to construct a coupling model of a single pile foundation area according to the computational fluid dynamics model and the hydrodynamic model; The third module is used to obtain the inlet boundary conditions and the outlet boundary conditions of the computational fluid dynamics model; The fourth module is used to simulate the scouring of the pile foundation group according to the coupling model, the inlet boundary condition and the outlet boundary condition to obtain the target simulation result.

9. An electronic device, characterized in that: including a processor and a memory; The memory is used to store programs; The processor executes the program to implement the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The storage medium stores a program, and the program is executed by a processor to implement the method according to any one of claims 1 to 7.

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