A fluid dynamics simulation test system and method for protecting a reciprocating flow under a human-shaped submerged dike offshore wind power pile foundation from scour

Abstract

The application discloses a kind of reciprocating flow under human-shaped submerged dike offshore wind power pile foundation scour protection fluid dynamics simulation test system and method, comprising: the present application is by collecting environment and reciprocating flow data, using fluid dynamics to establish the numerical model of the influence of reciprocating flow on pile foundation, numerical simulation is carried out by numerical model and human-shaped submerged dike and offshore wind power pile foundation model, and experiment verification is carried out, and numerical model is optimized, the angle of optimal human-shaped submerged dike, length, width and the spacing of human-shaped submerged dike and pile foundation are adopted to effectively reduce the scour of pile foundation, improve the durability and protection effect of human-shaped submerged dike;By establishing the numerical model of the influence of reciprocating flow on pile foundation based on S1 in S2 and using fluid dynamics principle, while establishing the physical model of offshore wind power pile foundation and human-shaped submerged dike in S3;Provide numerical model and physical model under the condition of reciprocating flow.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fluid dynamics testing, in particular to a fluid dynamics simulation test system and method for offshore wind power pile foundation scour protection under reciprocating flow of human-shaped submerged dike. BACKGROUND

[0002] Reciprocating flow refers to the opposite or basically opposite tidal flow due to the influence of topography. In the field of marine science and technology, it is regarded as the periodic flow of the straightening of the tidal flow ellipse;

[0003] Fluid dynamics is a discipline that studies the laws of fluid motion and its interaction with the boundary. In the design and application of human-shaped submerged dike, the principle of fluid dynamics plays a crucial role. By applying the principle of fluid dynamics, the stress condition, deformation characteristics and stability of human-shaped submerged dike under the action of reciprocating flow can be analyzed;

[0004] In the marine environment, the existence of pile foundation will change the original flow pattern around it, resulting in local scouring phenomenon around the pile foundation. This scouring phenomenon will affect the bearing capacity of the pile foundation and the safety of offshore wind turbines. Therefore, effective scour protection measures need to be taken to protect offshore wind power pile foundation, and human-shaped submerged dike can change the dynamic characteristics of the surrounding water flow through its special shape and structure, thereby reducing the scouring effect on the pile foundation;

[0005] In practical application, the fluid dynamics model needs to accurately reflect the complex marine environmental conditions, and the human-shaped submerged dike needs to be set near the pile foundation to protect the pile foundation, and the protection effect of the human-shaped submerged dike on the pile foundation needs to be tested many times;

[0006] Therefore, it is necessary to improve the existing technology of fluid dynamics numerical simulation of seabed energy dissipation net offshore wind power pile foundation scour protection test method under reciprocating flow to solve the above problems. SUMMARY

[0007] The present application overcomes the shortcomings of the prior art and provides a fluid dynamics simulation test system and method for offshore wind power pile foundation scour protection of human-shaped submerged dike under reciprocating flow.

[0008] To achieve the above purpose, the technical scheme adopted by the present application is as follows: a fluid dynamics simulation test system and method for offshore wind power pile foundation scour protection of human-shaped submerged dike under reciprocating flow, comprising:

[0009] S1, collecting the environmental data of the pile foundation and the reciprocating flow data of the area where it is located; wherein the environmental data includes: seabed slope, seabed topographic features and sediment characteristics data in the sea area; the reciprocating flow data includes flow velocity and flow direction data;

[0010] S2, based on the data of S1, a numerical model of the influence of reciprocating flow on the pile foundation is established by using the principle of fluid dynamics;

[0011] S3, a physical scale model of the offshore wind power pile foundation and the human-shaped submerged dike is constructed; in step S3, the angle of the human-shaped submerged dike is 10°-20°, the length of the human-shaped submerged dike is 1-3 times of the diameter of the pile foundation, the distance between the human-shaped submerged dike and the pile foundation is 1-4 times of the diameter of the pile foundation, and the width of the human-shaped submerged dike is 1-2 times of the diameter of the pile foundation;

[0012] S4, the experimental conditions are set according to the data of S1, and the physical scale model of S3 is used to perform a flume experiment to obtain experimental data;

[0013] S5, the numerical model established in S2 is used to perform numerical simulation on a numerical geometric model containing the pile foundation and the human-shaped submerged dike, to simulate the scouring process of the offshore wind power pile foundation and the human-shaped submerged dike under the action of reciprocating flow, and to obtain simulation data;

[0014] S6, the experimental data obtained in S4 is compared with the simulation data obtained in S5, and the numerical model in S2 is optimized.

[0015] In a preferred embodiment of the present application, the specific steps of collecting reciprocating flow data are as follows: an acoustic Doppler current profiler and a current meter are placed at the measurement point for measurement, and after processing the collected data, a flow velocity and flow direction diagram is made to intuitively display the situation of the reciprocating flow.

[0016] In step S2 of the present application, the specific steps are as follows:

[0017] S21, continuity equation and momentum equation are used as the core equations in this step to respectively describe the mass conservation and momentum conservation of the fluid;

[0018] Specifically, the continuity equation is:

[0019]

[0020] wherein, is the fluid density, and u is the fluid velocity vector;

[0021] The momentum equation is:

[0022]

[0023] wherein, p is the pressure, g is the gravity acceleration vector, μ is the dynamic viscosity, represents the vector Laplace operator, and F is the interaction force between the fluid and the pile foundation;

[0024] S22, a turbulent flow model equation is used:

[0025] A turbulent flow energy equation and a turbulent flow dissipation rate equation are used;

[0026] Turbulent kinetic energy equation: ;

[0027] Turbulent dissipation rate equation: ;

[0028] wherein, is turbulent kinetic energy, is turbulent dissipation rate, is turbulent viscosity, is turbulent kinetic energy generation term, and are empirical constants, and are Prandtl numbers, u is a fluid velocity vector;

[0029] S23, input the reciprocating flow data collected in S1 into the model as the boundary conditions of the model;

[0030] Use the seafloor slope and seafloor topographic feature data collected in S1 to construct the seafloor topography in the model; import the elevation data into the software and generate a three-dimensional topographic model; extract the seafloor slope and elevation data from S1 to construct the topographic slope formula: wherein, is the elevation difference of adjacent points, is the horizontal distance of adjacent points;

[0031] Input the sediment characteristics data collected in S1, including particle size distribution, density, and settling velocity, into the model to simulate the transport and deposition process of the sediment under the action of the reciprocating flow; the sediment characteristics input is: wherein, is the dynamic viscosity of water, is the density of water, and g is the gravity acceleration vector.

[0032] In a preferred embodiment of the present application, in step S3, the actual single-pile pile foundation diameter is 3-6m, and a scaled model pile foundation is arranged in the water tank, and the size and spacing of the scaled model pile foundation are scaled by 1:10-15 according to the actual situation, and the diameter of the scaled model pile foundation is 30-40cm.

[0033] In a preferred embodiment of the present application, in step S4, the water tank experiment is:

[0034] Build an experimental environment: the size of the water tank is 20m long, 4m wide and 2m high;

[0035] Prepare acoustic Doppler flowmeters, pressure sensors, displacement sensors and materials for simulating sediment inside; use the multi-beam sounding system data to construct the corresponding seafloor topographic model in the water tank, and ensure that the slope and topographic features meet the actual conditions;

[0036] The fine sand with a simulated particle size distribution of 0.01-0.1 mm is evenly laid at the bottom of the water tank, accounting for 40%-60% of the total sediment, and the high proportion of fine sand can simulate the suspension and transportation characteristics of sediment;

[0037] The medium sand with a particle size of 0.1-1 mm accounts for 25% to 35% of the total sediment, the particle size of the medium sand is larger, the settling velocity is faster, and the scouring effect on the submerged dike is more significant;

[0038] The coarse sand with a particle size greater than 1 mm accounts for 15% to 25% of the total sediment, the particle size of the coarse sand is the largest, the settling velocity is the fastest, and the local scouring effect on the submerged dike is the largest;

[0039] And the sediment density range is set to 2.55 g / cm³ to 2.65 g / cm³, which reflects the specific gravity of different types of sediment, and is crucial for simulating the movement and deposition behavior of sediment in water flow;

[0040] In the experiment, the measuring equipment is installed, and by installing water level meters, flowmeters, pressure sensors and displacement sensors in the water tank, it is ensured that the reciprocating flow can be monitored in real time;

[0041] The bidirectional pump is started to simulate the reciprocating water flow, and the set water flow conditions are generated to ensure that the flow rate and flow direction of the water flow are stably converted according to a fixed cycle;

[0042] The test water level is set to 0.05m-0.2m, which takes into account the extreme tidal level and storm surge water level, covering from mild to severe sea conditions, to ensure that the submerged dike design can cope with different reciprocating flow conditions;

[0043] The cycle range of the water flow is set to 1.5s-3s, reflecting the periodic change of the reciprocating flow, which is crucial for simulating the impact effect of the reciprocating flow on the submerged dike;

[0044] The flow rate range is set to 0.16m / s-0.48m / s, which simulates different intensities of tidal flow, which is very important for evaluating the stability and scour protection effect of the submerged dike under different flow rates.

[0045] In a preferred embodiment of the present application, in step s4, the execution steps of the water tank experiment are:

[0046] S41, start the bidirectional pump, gradually increase the flow rate to the set value, and ensure that the water flow is stable;

[0047] S42, use ADV or other flowmeters to measure the flow rate profile at different positions in the water tank, including before and after the submerged dike and both sides; record the time sequence of the flow rate data to capture the dynamic changes of the reciprocating flow and the flow rate;

[0048] S43, the pressure sensors and displacement sensors installed on the submerged dike and pile foundation record the changes of water pressure and the displacement of the submerged dike and pile foundation to evaluate the stability thereof;

[0049] S44, the depth of scouring before and after the submerged dike is measured regularly using a depth finder, and the change of the scouring range is evaluated by measuring the size of the scouring pit.

[0050] In a preferred embodiment of the present application, in step S6,

[0051] S61, the data of the flume experiment and numerical simulation are sorted out to ensure the consistency of time sequence, spatial position and measurement parameters;

[0052] The experimental data and simulation data are aligned in time and space using interpolation or fitting methods

[0053] ,

[0054] wherein, (x, y) are the points of two known planes, (x0, y0) are the plane coordinates of the demand value point; , ), (x0, y0) are the plane coordinates of the demand value point; , ) are the plane coordinates of the demand value point; , ;

[0055] S62, the significance of the difference is evaluated using statistical methods;

[0056] t-test:

[0057] ,

[0058] wherein, , are the means of the two groups of samples, is the combined standard deviation, , is the sample size;

[0059] S63, numerical simulation model optimization;

[0060] ,

[0061] wherein, is the density, u is the velocity vector, p is the pressure, g is the acceleration of gravity, is the dynamic viscosity;

[0062] The corresponding optimization considering the turbulent flow effect is:

[0063] ,

[0064] , ​

[0065] where k is the turbulent kinetic energy, is the turbulent dissipation rate, is the turbulent viscosity, is the turbulent production term, is a model constant, u is the fluid velocity vector;

[0066] S64, using an error analysis method to evaluate the difference between the simulation results and the experimental data

[0067]

[0068] wherein, is the experimental data, is the simulation data, n is the number of data points.

[0069] The present application solves the defects in the background art, and has the following beneficial effects:

[0070] The present application collects environmental and reciprocating flow data, uses fluid dynamics to establish a numerical model of the influence of reciprocating flow on pile foundation, performs numerical simulation on the numerical model, human-shaped submerged dike and offshore wind power pile foundation model, and verifies the numerical model through experiments, optimizes the numerical model, optimizes the angle, length, width of the human-shaped submerged dike and the distance between the human-shaped submerged dike and the pile foundation, so as to effectively reduce the scouring of the pile foundation and improve the durability and protection effect of the human-shaped submerged dike.

[0071] The present application establishes a numerical model of the influence of reciprocating flow on pile foundation based on the data of S1 and fluid dynamics in S2, and establishes a physical model of offshore wind power pile foundation and human-shaped submerged dike in S3; provides a numerical model and a physical model under the condition of reciprocating flow; compared with the prior art, the degree of influence of the pile foundation under the condition of reciprocating flow is more obvious, and the structure of the human-shaped submerged dike can be adjusted synchronously after experimental verification, thereby reducing the scouring of the pile foundation.

[0072] The present application further optimizes the angle, length, width of the human-shaped submerged dike, the distance between the human-shaped submerged dike and the pile foundation and the material of the human-shaped submerged dike through the numerical model of the human-shaped submerged dike in S3 and verification through a water tank experiment, so as to achieve the best protection effect on the pile foundation.

[0073] The present application combines the numerical model of S2 and the experimental verification of S4, has numerical basis and actual experimental support, which not only verifies the accuracy of the numerical model, but also optimizes the structure of the human-shaped submerged dike, so as to achieve the best protection effect on the pile foundation. BRIEF DESCRIPTION OF DRAWINGS

[0074] ​​​In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings described below only illustrate some of the embodiments of the present application, and other drawings can be obtained by those of ordinary skill in the art without any creative effort.

[0075] Figure 1 is a flowchart of a preferred embodiment of the present application.

[0076] Figure 2 is a schematic diagram of a pile foundation and a humanoid submerged dike of the present application. DETAILED DESCRIPTION

[0077] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort fall within the scope of protection of the present application.

[0078] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in other manners different from those described herein. Therefore, the scope of the present application is not limited by the specific embodiments disclosed below.

[0079] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more.

[0080] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0081] As shown in Figure 1 A kind of reciprocating flow under human-shaped submerged dike offshore wind power pile foundation scour protection fluid dynamics simulation test system and method, comprising:

[0082] S1, the environmental data of pile foundation and the reciprocating flow data of the region where it is located are collected;

[0083] S2, based on the data of S1, a numerical model of the influence of reciprocating flow on pile foundation is established using fluid dynamics principles;

[0084] S3, a physical scale model of offshore wind power pile foundation and human-shaped submerged dike is constructed;

[0085] S4, according to the data of S1, set the experimental conditions, and use the physical scale model of S3 to carry out flume experiment, obtain experimental data;

[0086] S5, using the numerical model established in S2, a numerical simulation is carried out on the numerical geometric model containing pile foundation and human-shaped submerged dike, the scouring process of offshore wind power pile foundation and human-shaped submerged dike under the action of reciprocating flow is simulated, and simulation data is obtained;

[0087] S6, comparing the experimental data obtained in S4 with the simulation data obtained in S5, optimizing the numerical model in S2;

[0088] Further, in step S1, the environmental data includes: seabed slope, seabed geomorphic feature and sediment characteristic data in sea area;

[0089] Specifically, the specific operation of collecting seabed slope and seabed geomorphic feature data is: using multi-beam sounding system to scan seabed of sampling point, obtaining elevation data of seabed topography, and then calculating seabed slope. At the same time, through post-processing of multi-beam data, seabed geomorphic features can be extracted.

[0090] Sampling point selection: latitude 32°28'23"N, longitude 121°54'32"E, water depth of 20m area;

[0091] Sediment characteristic data include particle size distribution, density, and settling velocity data. The specific collection steps are as follows: use a grab sampler to collect sediment samples and send them to the laboratory for detailed physicochemical analysis (analysis of particle size distribution, density, and settling velocity).

[0092] In the particle size distribution of sediment, particles between 0.01 and 0.1 mm account for 50%, particles between 0.1 and 1 mm account for 30%, and particles larger than 1 mm account for 20%.

[0093] The density of the sediment is between 2.60 and 2.70 g / cm³.

[0094] The sediment settling velocity is between 0.015 and 0.087.5 cm / s;

[0095] In step S1, the reciprocating flow data includes data such as flow velocity and flow direction. The specific steps for collecting the reciprocating flow data are: using an acoustic Doppler current meter (ADCP) and a current meter placed at the measurement point for measurement, processing the collected data, and creating a flow velocity and flow direction diagram to visually display the reciprocating flow situation.

[0096] Furthermore, in step S2, the specific steps are as follows:

[0097] The continuity equation and momentum equation are selected as the core equations in this step, which describe the conservation of mass and momentum of the fluid, respectively.

[0098] Specifically, the continuity equation:

[0099] in, Where is the fluid density, and u is the fluid velocity vector;

[0100] Momentum equation:

[0101] Where p is pressure, g is the gravitational acceleration vector, and μ is dynamic viscosity. Let F represent the vector Laplace operator, where F is the interaction force between the fluid and the pile foundation.

[0102] Turbulence model equations:

[0103] The turbulent kinetic energy equation and the turbulent dissipation rate equation are selected.

[0104] Turbulent kinetic energy equation: ;

[0105] Turbulent dissipation rate equation: ;

[0106] in, It is turbulent kinetic energy. It is the turbulent dissipation rate. It is turbulent viscosity. is a turbulent kinetic energy generation term, is an empirical constant, is a Prandtl number, u is the fluid velocity vector.

[0107] Further, the reciprocating flow data (flow velocity and flow direction) collected in S1 is input into the model as the boundary conditions of the model;

[0108] The seabed slope and seabed geomorphic feature data collected in S1 are used to construct the seabed topography in the model. This usually involves importing elevation data into the software and generating a three-dimensional topographic model; the seabed slope (a) and elevation (z) data are extracted from S1 to construct the topographic slope formula: is the elevation difference of adjacent points,

[0109] The sediment characteristics data (grain size distribution, density, settling velocity) collected in S1 are input into the model to simulate the transport and deposition of sediment under the action of reciprocating flow; the sediment characteristics input: is the dynamic viscosity of water,

[0110] In step S3, specifically:

[0111] 87.5cm87.5cm The actual single pile foundation diameter is 3-6m, and the scale model pile foundation is arranged in the water tank, and the size and spacing of the scale model pile foundation are scaled 1:10-15 according to the actual situation, and the scale model pile foundation diameter is 30-40cm;

[0112] The design of the double human-shaped submerged dike changes the flow direction and velocity of the water flow by adjusting the angle and width of the human-shaped submerged dike, reducing the direct impact of the water flow on the pile foundation, effectively dispersing the reciprocating flow energy, and reducing the direct impact on the pile foundation. This design can reduce the risk of local scouring and protect the stability of the pile foundation; the elevation of the top of the submerged dike is calculated according to the climbing height of the reciprocating flow to ensure that it can still effectively protect the pile foundation under extreme weather conditions.

[0113] The material of the submerged dike is usually concrete or stone to ensure its durability and stability in the marine environment;

[0114] For example, Figure 2 ​​​​​​As shown, the detailed structure of the double humanoid submerged dike type humanoid submerged dike is designed, including the angle of the humanoid submerged dike being 10°-20°, the length of the humanoid submerged dike being 1-3 times the diameter of the pile foundation, the spacing between the humanoid submerged dike and the pile foundation being 1-4 times the diameter of the pile foundation, and the width of the humanoid submerged dike being 1-2 times the diameter of the pile foundation. Such design helps to disperse the water flow and reduce the direct scouring of the pile foundation;

[0115] The angle of the humanoid submerged dike is 10°-20°, which can provide good water flow dispersion effect and reduce the impact force of the reciprocating flow on the front of the submerged dike. This design is based on the principle of fluid dynamics, especially the optimization of the energy dispersion efficiency of the reciprocating flow and the water flow;

[0116] The length of the humanoid submerged dike is 1-3 times the diameter of the pile foundation. This length setting can ensure sufficient water flow dispersion area, so that the reciprocating flow and the water flow have enough distance and time to disperse their energy before reaching the pile foundation, reducing the direct impact on the pile foundation;

[0117] The width of the humanoid submerged dike is 1-2 times the diameter of the pile foundation: the width setting ensures that the water flow has enough space to disperse on both sides of the submerged dike, avoiding the concentration of water flow to cause erosion to the submerged dike and the pile foundation

[0118] The spacing between the humanoid submerged dike and the pile foundation is 1-4 times the diameter of the pile foundation: this spacing can ensure that the submerged dike can effectively change the flow field and reduce the scouring of the pile foundation. At the same time, this spacing also considers the feasibility of construction and the convenience of maintenance;

[0119] The material of the humanoid submerged dike is usually a permeable material composed of porous concrete and gravel, or a non-permeable material composed of concrete and reinforced concrete; the humanoid submerged dike composed of permeable material allows water flow, which helps to accumulate sediment and improve water quality; the humanoid submerged dike composed of non-permeable material is mainly used to change the direction of water flow and dissipate the energy of reciprocating flow.

[0120] In step S4, the water tank experiment is:

[0121] Build the experimental environment: the size of the water tank is 20m long, 4m wide and 2m high;

[0122] Prepare acoustic Doppler current profiler (ADV), pressure sensor, displacement sensor and material for simulating sediment inside; use multi-beam depth sounding system data to build corresponding seabed topography model in the water tank to ensure that the slope and topographic features meet the actual conditions;

[0123] Uniformly lay fine sand with simulated particle size distribution of 0.01-0.1mm and accounting for 40%-60% of the total sediment on the bottom of the water tank; the high proportion of fine sand can simulate the suspension and transportation characteristics of sediment;

[0124] 0.1-1mm medium sand, accounting for 25% to 35% of the total sediment, with larger particle size and faster settling velocity, having more significant scouring effect on the submerged dike;

[0125] Coarse sand greater than 1mm, accounting for 15% to 25% of the total sediment, with the largest particle size and the fastest settling velocity, having the most significant local scouring effect on the submerged dike.

[0126] And the sediment density range is set at 2.55g / cm³ to 2.65g / cm³, which reflects the specific gravity of different types of sediment, which is crucial for simulating the movement and deposition behavior of sediment in water flow.

[0127] In the experiment, the installation of measuring equipment ensures real-time monitoring of the effect of water flow and reciprocating flow on the submerged dike by installing flow meters, pressure sensors and displacement sensors in the water tank;

[0128] By starting the bidirectional pump to simulate reciprocating water flow, ensure the stability of flow rate and flow direction conversion period, and adjust the flow rate to meet the test conditions;

[0129] The test water level is set at 0.05m-0.2m, which takes into account extreme tidal levels and storm surge water level changes, covering from mild to severe sea conditions, to ensure that the submerged dike design can cope with different reciprocating flow conditions;

[0130] The cycle range of reciprocating flow is set at 1.5s-3s, reflecting the periodic changes of reciprocating flow, which is crucial for simulating the impact effect of reciprocating flow on the submerged dike;

[0131] The flow rate range is set at 0.16m / s-0.48m / s, which simulates different intensity of tidal flow, which is very important for evaluating the stability and scour protection effect of the submerged dike under different flow rate conditions;

[0132] Real-time collected flow rate, pressure, displacement data and scour depth and range around the submerged dike will be used to analyze the performance of the submerged dike and evaluate its protection effect on pile foundation scour; observe the effect of water flow and reciprocating flow on the submerged dike and pile foundation, record the scouring and deposition phenomena, these observations will provide direct evidence for verifying the numerical model and improving the design of the submerged dike; analyze the collected data to evaluate the performance of the submerged dike, such as flow dispersion effect, scour reduction effect, etc., these analysis results will directly guide the optimization of the submerged dike design.

[0133] In step s4, the execution steps of the water tank experiment are:

[0134] S41, start the bidirectional pump, gradually increase the flow rate to the set value, ensure the stability of the water flow;

[0135] S42, measure the flow velocity profile at different locations of the flume, including before and after the submerged dike and on both sides, using ADV or other flow meters; record the time series of flow velocity data to capture the dynamic changes of the reciprocating flow and flow velocity.

[0136] S43, the pressure sensors and displacement sensors installed on the submerged dike and pile foundation record the changes of water pressure and the displacement of the submerged dike and pile foundation to evaluate their stability;

[0137] S44, use the depth finder to measure the scour depth before and after the submerged dike regularly, and evaluate the changes of the scour range by measuring the size of the scour pit. Embodiment 1

[0138] A flume experiment, comprising:

[0139] A flume physical model with a size of 20m long, 4m wide and 2m high is constructed, and fine sand with a simulated particle size distribution of 0.01-0.1mm, accounting for 50% of the total sediment, medium sand with a particle size of 0.1-1mm, accounting for 30% of the total sediment, and coarse sand with a particle size greater than 1mm, accounting for 20% of the total sediment, are uniformly laid on the bottom of the flume.

[0140] The actual single pile foundation has a diameter of 3.5m, so the scale model pile foundation has a diameter of 35cm,

[0141] The reciprocating flow data simulated by the bidirectional pump is set at a water level of 0.35m, a conversion period of the reciprocating flow is set at 2s, and the flow velocity is set at 0.25m / s,

[0142] The angle of the human-shaped submerged dike is 15°,

[0143] The length of the human-shaped submerged dike is 2 times the diameter of the pile foundation, i.e. 70cm;

[0144] The width of the human-shaped submerged dike is 1.5 times the diameter of the pile foundation, i.e. 52.5cm;

[0145] The spacing between the human-shaped submerged dike and the pile foundation is 2.5 times the diameter of the pile foundation, i.e. 87.5cm; it is arranged around the scale model pile foundation;

[0146] The human-shaped submerged dike is composed of porous concrete and gravel; Embodiment 2

[0147] A flume experiment, the same as that of embodiment 1, the difference between this embodiment and embodiment 1 is that;

[0148] The angle of the human-shaped submerged dike is 10°; Embodiment 3

[0149] A flume experiment, the same as that of embodiment 1, the difference between this embodiment and embodiment 1 is that;

[0150] The angle of the human-shaped submerged dike is 20°; Example 4

[0151] A flume experiment, the same as that of Example 1, is not repeated here, and the difference between this example and Example 1 is that:

[0152] The length of the human-shaped submerged dike is 1.2 times the diameter of the pile foundation, i.e. 42 cm; Example 5

[0153] A flume experiment, the same as that of Example 1, is not repeated here, and the difference between this example and Example 1 is that:

[0154] The length of the human-shaped submerged dike is 3 times the diameter of the pile foundation, i.e. 105 cm; Example 6

[0155] A flume experiment, the same as that of Example 1, is not repeated here, and the difference between this example and Example 1 is that:

[0156] The width of the human-shaped submerged dike is 1 times the diameter of the pile foundation, i.e. 35 cm; Example 7

[0157] A flume experiment, the same as that of Example 1, is not repeated here, and the difference between this example and Example 1 is that:

[0158] The width of the human-shaped submerged dike is 2 times the diameter of the pile foundation, i.e. 70 cm; Example 8

[0159] A flume experiment, the same as that of Example 1, is not repeated here, and the difference between this example and Example 1 is that:

[0160] The distance between the human-shaped submerged dike and the pile foundation is 1 times the diameter of the pile foundation, i.e. 35 cm; Example 9

[0161] A flume experiment, the same as that of Example 1, is not repeated here, and the difference between this example and Example 1 is that:

[0162] The distance between the human-shaped submerged dike and the pile foundation is 2 times the diameter of the pile foundation, i.e. 70 cm; Example 10

[0163] A flume experiment, the same as that of Example 1, is not repeated here, and the difference between this example and Example 1 is that:

[0164] The distance between the human-shaped submerged dike and the pile foundation is 3 times the diameter of the pile foundation, i.e. 105 cm; Example 11

[0165] A flume experiment, the same as that of embodiment 1, the difference between this embodiment and embodiment 1 is that;

[0166] The distance between the human-shaped submerged dike and the pile foundation is 4 times the diameter of the pile foundation, i.e. 140 cm; Embodiment 12

[0167] A flume experiment, the same as that of embodiment 1, the difference between this embodiment and embodiment 1 is that;

[0168] No human-shaped submerged dike is arranged near the scale model pile foundation. Embodiment 13

[0169] A flume experiment, the same as that of embodiment 1, the difference between this embodiment and embodiment 1 is that;

[0170] The human-shaped submerged dike is composed of a porous concrete and a permeable material composed of gravel;

[0171] Experimental example 1

[0172] In this experiment, embodiments 1, 4-7 and 12 are selected to detect the wave height in front of the scale model human-shaped submerged dike and the wave height behind the scale model human-shaped submerged dike and the energy dissipation efficiency, as well as the front flow velocity and the rear flow velocity and the flow velocity reduction rate and other parameters after 24 hours; the experimental data are shown in Table 1;

[0173]

[0174] According to the data in Table 1, it can be obtained that the wave height reduction rate and the flow velocity reduction rate of the human-shaped submerged dike with a length of 2 times the diameter of the pile foundation, i.e. 70 cm, and a width of 1.5 times the diameter of the pile foundation, i.e. 52.5 cm, are the highest, indicating that the human-shaped submerged dike with this length and width has the best protection effect on the reciprocating flow; it is indicated that under the length and width of the human-shaped submerged dike, when the reciprocating flow encounters the submerged dike, the water molecules in the reciprocating flow collide with the surface of the submerged dike, and most of the kinetic energy is converted into heat energy or other forms of energy (such as vortex energy). The water molecules in the front of the reciprocating flow are greatly slowed down, and the wave height is thus reduced the most; and when the water flow passes through the submerged dike, the flow path is most restricted, and according to Bernoulli's equation in fluid mechanics, the flow velocity is thus slowed down the most, and the resistance between water molecules is effectively and greatly increased.

[0175] According to Table 1, the human-shaped submerged dike with a length of 2 times the diameter of the pile foundation, i.e. 70 cm, and a width of 1.5 times the diameter of the pile foundation, i.e. 52.5 cm, is the best in reducing the reciprocating flow scouring in terms of the effect of resisting scouring.

[0176] Experimental example 2

[0177] The present experiment selects example 1, example 2-3, and example 12, detects the wave height in front of the scaled model human-shaped submerged dike and the wave height behind the scaled model human-shaped submerged dike and the energy dissipation efficiency, and the flow velocity in front of the scaled model human-shaped submerged dike and the flow velocity behind the scaled model human-shaped submerged dike and the flow velocity reduction rate and other parameters after 24 hours; the experimental data are as shown in Table 2.

[0178]

[0179] According to the data in Table 2, it can be obtained that the wave height reduction rate and the flow velocity reduction rate of the human-shaped submerged dike with an angle of 15° are the highest, which indicates that the human-shaped submerged dike with this angle has the best protection effect on the reciprocating flow; the reason is that: at the angle of example 1, after the reciprocating flow hits the submerged dike, more amount of vortex flow and turbulent flow is generated, and the water molecules in these vortex flow and turbulent flow are in a highly disordered state, and their kinetic energy is rapidly converted into internal energy and dissipated. The angle of the submerged dike in example 1 promotes the generation of vortex flow and turbulent flow more effectively, thereby improving the energy dissipation efficiency; at the same time, at this angle, more amount of friction and collision between water molecules is increased, and the hydrodynamic resistance is more effectively increased, thereby achieving a higher flow velocity reduction effect.

[0180] Experimental example 3

[0181] The present experiment selects example 1, example 8-11, and example 12, detects the wave height in front of the scaled model human-shaped submerged dike and the wave height behind the scaled model human-shaped submerged dike and the energy dissipation efficiency, and the flow velocity in front of the scaled model human-shaped submerged dike and the flow velocity behind the scaled model human-shaped submerged dike and the flow velocity reduction rate and other parameters after 24 hours; the experimental data are as shown in Table 3.

[0182]

[0183] According to the data in Table 3, it can be obtained that the wave height reduction rate and the flow velocity reduction rate of the human-shaped submerged dike with a distance between the human-shaped submerged dike and the pile foundation of 2.5 times the diameter of the pile foundation, i.e. 87.5 cm, are the highest, which indicates that the human-shaped submerged dike with this angle has the best protection effect on the reciprocating flow; the reason is that: at the angle of example 1, the human-shaped submerged dike has a distance between the human-shaped submerged dike and the pile foundation of 2.5 times the diameter of the pile foundation, and at this distance, the space between the submerged dike and the pile foundation can form an optimized energy dissipation area, which allows water molecules to have more sufficient space for conversion of kinetic energy and potential energy after being hindered by the submerged dike, thereby more effectively dissipating the reciprocating flow energy; at the distance of 2.5 times the diameter of the pile foundation, the design of the submerged dike effectively suppresses the generation of excessive turbulent flow, while retaining sufficient vortex flow to dissipate the reciprocating flow energy; ultimately resulting in the highest flow velocity reduction rate and wave height reduction rate and better realization of the anti-scouring effect.

[0184] Experimental example 4

[0185] This experiment selected Examples 1, 13, and 12 to detect the wave height in front of and behind the scaled humanoid submerged breakwater, energy dissipation efficiency, flow velocity in front of and behind the breakwater, and velocity reduction rate after 24 hours; the experimental data are shown in Table 4.

[0186]

[0187] According to the data in Table 4, the human-shaped submerged dike composed of permeable material made of porous concrete and crushed stone has the highest wave height reduction rate and flow velocity reduction rate, indicating that the human-shaped submerged dike at this angle has the best protection effect for reciprocating flow.

[0188] In step S6,

[0189] S61. Organize the data from the water tank experiment and numerical simulation to ensure consistency in time series, spatial location, and measurement parameters.

[0190] Use interpolation or fitting methods to align experimental and simulated data in time and space.

[0191] ,

[0192] in,( , (), , Let be two known points on a plane, ( , ), which are the planar coordinates of the required value point;

[0193] S62. Use statistical methods to assess the significance of differences;

[0194] t-test:

[0195] ,

[0196] in, , The mean of the two samples is denoted as . To combine standard deviations, , This represents the sample size.

[0197] S63. Numerical simulation model optimization;

[0198] ,

[0199] in, Let p be density, u be velocity vector, p be pressure, and g be gravitational acceleration. This refers to dynamic viscosity.

[0200] Also considering turbulence effects, the corresponding optimization is:

[0201] ,

[0202] ,

[0203] where k is the turbulent kinetic energy, is the turbulent dissipation rate, is the turbulent viscosity, is the turbulent production term, , , is a model constant, and u is the fluid velocity vector.

[0204] S64, using an error analysis method to evaluate the difference between the simulation results and the experimental data

[0205] ,

[0206] where, is the experimental data, is the simulation data, and n is the number of data points.

[0207] The above is based on the ideal embodiment of the present application, through the above description, relevant personnel can make various changes and modifications without deviating from the scope of the technical idea of the present application. The technical scope of the present application is not limited to the contents of the specification, and the technical scope must be determined according to the scope of claims.

Claims

1. A hydrodynamic simulation test method for protecting a wind power pile foundation from scouring by a reciprocating flow under a humanoid submerged dike at sea, characterized in that, The method comprises the following steps: S1, collecting environmental data of the pile foundation and reciprocating flow data of the area where the pile foundation is located; wherein the environmental data comprises seabed slope, seabed topographic features and sediment characteristic data in the sea area; the reciprocating flow data comprises flow velocity and flow direction data; S2, based on the data of S1, a numerical model of the influence of reciprocating flow on the pile foundation is established by using the principle of fluid dynamics; S3, a physical scale model of the offshore wind power pile foundation and the human-shaped submerged dike is constructed; in step S3, the angle of the human-shaped submerged dike is 10°-20°, the length of the human-shaped submerged dike is 1-3 times of the diameter of the pile foundation, the distance between the human-shaped submerged dike and the pile foundation is 1-4 times of the diameter of the pile foundation, and the width of the human-shaped submerged dike is 1-2 times of the diameter of the pile foundation; S4, the experimental conditions are set according to the data of S1, and the physical scale model of S3 is used to carry out a water tank experiment to obtain experimental data; S5, the numerical model established in S2 is used to carry out numerical simulation on the numerical geometric model containing the pile foundation and the human-shaped submerged dike, to simulate the scouring process of the offshore wind power pile foundation and the human-shaped submerged dike under the action of reciprocating flow, and to obtain simulation data; S6, the experimental data obtained in S4 is compared with the simulation data obtained in S5, and the numerical model in S2 is optimized.

2. The fluid dynamics simulation test method for the reciprocating flow under the human-shaped submerged dike offshore wind power pile foundation scour protection according to claim 1, characterized in that: The specific steps of collecting reciprocating flow data are as follows: an acoustic Doppler current profiler and a current meter are placed at the measurement point for measurement, and after processing the collected data, a flow velocity and flow direction diagram is made to intuitively show the situation of the reciprocating flow.

3. The fluid dynamics simulation test method of protecting the pile foundation of the offshore wind power pile from scour according to claim 1, characterized in that: In step S2, the specific steps are as follows: S21, continuity equation and momentum equation are used as the core equations in this step to describe the mass conservation and momentum conservation of the fluid, respectively; In particular, the continuity equation: ; where, is the fluid density, u is the fluid velocity vector; Momentum equation: ; where p is the pressure, g is the gravitational acceleration vector, and μ is the dynamic viscosity, denotes the vector Laplacian, and F is the interaction force between the fluid and the pile foundation; S22, a turbulence model equation is used: a turbulence kinetic energy equation and a turbulence dissipation rate equation are used; Turbulent kinetic energy equation: ; Turbulent dissipation rate equation: ; wherein is the turbulent kinetic energy, is the turbulent dissipation rate, is the turbulent viscosity, is the turbulent kinetic energy production term, and is an empirical constant, and is the Prandtl number, u is the fluid velocity vector; S23, the reciprocating flow data collected in S1 is input into the model as the boundary condition of the model; The seabed terrain in the model is constructed by using the seabed slope and seabed geomorphic feature data collected in S1; the elevation data is imported into the software, and a three-dimensional terrain model is generated; the seabed slope and elevation data are extracted from S1, and a terrain slope formula is constructed: wherein, is the elevation difference of adjacent points, is the horizontal distance of adjacent points; The collected data of sediment properties, including grain size distribution, density, settling velocity, in S1 are input into the model to simulate the transport and deposition of sediment under the action of the reciprocating flow; the sediment properties input: ; wherein, is the dynamic viscosity of water, is the density of water, and g is the gravity acceleration vector.

4. The fluid dynamics simulation test method of protecting the wind power pile foundation from scour according to the reciprocating flow under the human-shaped submerged dike on the sea, according to claim 1, characterized in that: In step S3, the actual single-pile foundation has a diameter of 3-6 m, and a scale model pile foundation is arranged in the water tank, and the size and spacing of the scale model pile foundation are scaled by 1:10-15 according to the actual situation, and the diameter of the scale model pile foundation is 30-40 cm.

5. The fluid dynamics simulation test method of protecting the wind power pile foundation of the reciprocating flow under the human-shaped submerged dike from scour on the sea according to claim 1, characterized in that: In step S4, the water tank experiment is as follows: An experimental environment is built: the size of the water tank is 20 m long, 4 m wide and 2 m high; An acoustic Doppler current profiler, a pressure sensor, a displacement sensor and a material for simulating sediment are prepared inside; a corresponding seabed topographic model is constructed in the water tank by using multi-beam sounding system data to ensure that the slope and topographic features meet the actual conditions; Fine sand with a simulated particle size distribution of 0.01-0.1 mm, accounting for 40%-60% of the total sediment, is uniformly laid on the bottom of the water tank, and a high proportion of fine sand can simulate the suspension and transportation characteristics of sediment; 0.1-1 mm medium sand, accounting for 25% to 35% of the total sediment, has a larger particle size and faster settling velocity, and has a more significant scouring effect on the submerged dike; Coarse sand with a particle size greater than 1 mm, accounting for 15% to 25% of the total sediment, has the largest particle size and the fastest settling velocity, and has the greatest impact on local scouring of the submerged dike; And the sediment density range is set to 2.55 g / cm³ to 2.65 g / cm³, which reflects the specific gravity of different types of sediment and is crucial for simulating the movement and deposition behavior of sediment in water flow; The experimental equipment is installed by placing water level gauges, flow meters, pressure sensors, and displacement sensors in the flume to ensure real-time monitoring of the effects of the reciprocating flow on the submerged dike. The reciprocating flow is simulated by starting the bidirectional pump to generate the specified flow conditions, ensuring that the flow rate and direction are stable and change according to a fixed cycle. The test water level is set between 0.05m and 0.2m, which takes into account extreme tidal levels and storm surge water level changes, covering from mild to severe sea conditions to ensure that the submerged dike design can handle different reciprocating flow conditions. The flow cycle range is set between 1.5s and 3s, reflecting the periodic changes of the reciprocating flow, which is crucial for simulating the impact of the reciprocating flow on the submerged dike. The flow rate range is set between 0.16m / s and 0.48m / s, which simulates different strengths of tidal flow, which is very important for evaluating the stability and scour protection effect of the submerged dike under different flow conditions.

6. The fluid dynamics simulation test method of protecting the pile foundation of offshore wind power from scour according to claim 5, wherein: In step s4, the execution steps of the flume experiment are as follows: S41, start the bidirectional pump and gradually increase the flow rate to the set value to ensure stable flow; S42, use ADV or other flow meters to measure the flow rate profile at different positions in the flume, including before and after the submerged dike and on both sides; record the time series of flow rate data to capture the dynamic changes of the reciprocating flow and flow rate; S43, install pressure sensors and displacement sensors on the submerged dike and pile foundation to record changes in water pressure and displacement of the submerged dike and pile foundation to evaluate their stability; S44, use the depth sounder to measure the scour depth before and after the submerged dike regularly, and evaluate the changes in the scour range by measuring the size of the scour pit.

7. The fluid dynamics simulation test method of protecting the wind power pile foundation of the reciprocating flow under the human-shaped submerged dike from scour on the sea according to claim 1, characterized in that: In step S6, S61, organize the data from the flume experiment and numerical simulation to ensure consistency in time series, spatial location, and measurement parameters; Experimental data and simulation data are aligned in time and space using interpolation or fitting methods, wherein (x, y, z) are the coordinates of a point on the plane, , (x, y, z) are the coordinates of a point on the plane, , (x, y, z) are the coordinates of a point on the plane, , are the plane coordinates of the demand value point; S62, use statistical methods to evaluate the significance of the differences; t-test: where, , is the mean of the two groups, is the pooled standard deviation, , is the sample size; S63, numerical simulation model optimization; , wherein is the density, u is the velocity vector, p is the pressure, g is the gravitational acceleration, is the dynamic viscosity; Also taking into account the turbulence effect, the corresponding optimization is: , ， where k is the turbulent kinetic energy, is the turbulent dissipation rate, is the turbulent viscosity, is the turbulent production term, , , is a model constant, u is the fluid velocity vector; S64, using error analysis methods to assess differences between simulation results and experimental data , wherein, is experimental data, is simulated data, n is the number of data points.

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