A method, system, medium, and apparatus for configuring a pipeline in an ocean current

Abstract

The application provides a method, system, medium and device for pipeline configuration in ocean current, which comprehensively considers the stratification effect of ocean current by establishing a stratified flow field, can accurately simulate the movement of fluid around the pipeline, and thus more truly reflects the interaction between the fluid and the pipeline. Meanwhile, the boundary source term is calculated according to the relationship between the fluid velocity on the surface of the pipeline and the displacement of the pipeline surface, so that the boundary source term can accurately represent the fluid reaction force caused by the movement of the pipeline surface. The nonlinear elastic deformation model of the pipeline under the deformation condition is constructed, which can well represent the stress tensor of the pipeline. Finally, the immersed boundary method is used to take the boundary source term as the pipeline surface force, which can handle the fluid and solid interaction problem under complex boundary conditions. Through iterative updating of the flow velocity and the displacement of the pipeline surface, the convergence of the pipeline elastic mechanics equation is obtained, which provides an important reference for the design, installation and maintenance of the pipeline configuration process.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of industrial control, and in particular to a pipeline configuration method, system, medium and device in ocean current. BACKGROUND

[0002] The deep-sea mining pipeline needs to withstand multiple loads such as ocean current disturbance and internal slurry flow, and the error of the traditional linear model is significant. The existing method mainly adopts one-way coupling or simplifies the boundary condition, which cannot reflect the real interaction between the fluid and the pipeline, and the error is large. Therefore, how to improve the pipeline configuration precision and accuracy in deep sea is a technical problem that needs to be solved by those skilled in the art. SUMMARY

[0003] The purpose of the present application is to provide a pipeline configuration method, system, computer readable storage medium and electronic device in ocean current, which can improve the pipeline configuration precision and accuracy in deep sea.

[0004] To solve the above technical problems, the present application provides a pipeline configuration method in ocean current, and the specific technical solutions are as follows:

[0005] Obtain ocean current data and determine the flow velocity distribution of each flow layer of the ocean current data;

[0006] Take the layered flow velocity field containing the flow velocity distribution of each flow layer as the initial condition of the Navier-Stokes equation, and calculate the corresponding relationship between the pipeline surface fluid velocity and the pipeline surface displacement; the Navier-Stokes equation is used to describe the motion of the fluid;

[0007] Calculate the boundary source term according to the corresponding relationship between the pipeline surface fluid velocity and the pipeline surface displacement; the boundary source term is used to represent the fluid reaction force caused by the movement of the pipeline surface;

[0008] Construct a nonlinear elastic deformation model of the pipeline under deformation condition, and the nonlinear elastic deformation model is used to represent the stress tensor of the pipeline;

[0009] Take the boundary source term as the pipeline surface force, combine the stress tensor of the pipeline, substitute into the pipeline elastomechanics equation, use the immersed boundary method to couple and calculate the pipeline elastomechanics equation, and iteratively update the flow velocity and the pipeline surface displacement until the pipeline elastomechanics equation converges to obtain the pipeline configuration indication information.

[0010] Optionally, determining the flow velocity distribution of each flow layer of the ocean current data comprises:

[0011] Fit the flow velocity distribution of each flow layer of the ocean current data by an exponential function or a logarithmic law, and use a disturbance function to simulate the turbulent flow in the ocean current data.

[0012] Optionally, the correspondence between the pipe surface fluid velocity and the pipe surface displacement further comprises:

[0013] According to the friction coefficient, a nonlinear friction force between a velocity field of the fluid in the pipe and a pipe surface displacement field is calculated;

[0014] The nonlinear friction force is added to a boundary source term to be coupled into the Navier-Stokes equation.

[0015] Optionally, constructing the nonlinear elastic deformation model of the pipe under the deformation condition comprises:

[0016] According to the initial coordinates and the coordinates after deformation of the pipe, a deformation gradient tensor of the pipe is defined;

[0017] According to a unit matrix and the deformation gradient tensor, a Lagrangian strain tensor is calculated; the Lagrangian strain tensor is used to represent a response result of the pipe to a disturbance;

[0018] According to the deformation gradient tensor, a stress tensor of the pipe is calculated; the stress tensor is used to represent a stress state of the pipe in the deformation process;

[0019] An equivalent relationship between the stress tensor, an elastic tensor of the pipe material and the Lagrangian strain tensor is established to obtain the nonlinear elastic deformation model of the pipe under the deformation condition.

[0020] Optionally, calculating the stress tensor of the pipe according to the deformation gradient tensor comprises:

[0021] According to the deformation gradient tensor, Lamé constants of the pipe material, a unit tensor and a shear modulus of the pipe material, the stress tensor of the pipe is calculated.

[0022] Optionally, when constructing the nonlinear elastic deformation model of the pipe under the deformation condition, the method further comprises:

[0023] According to a gradient tensor of the displacement field, a second-order strain tensor of the pipe is calculated; the second-order strain tensor is used to describe nonlinear shear and rotation effects of the pipe in deformation to correct the stress tensor.

[0024] Optionally, the method for coupling and calculating the pipe elastic mechanics equation by using the immersed boundary method, iteratively updating the flow velocity and the pipe surface displacement, and obtaining the pipe configuration indication information when the pipe elastic mechanics equation converges comprises:

[0025] The surface grid node displacement of the pipe is mapped to the layered flow velocity field through an interpolation function to obtain a boundary source term;

[0026] A discrete function is added, and a residual threshold is set; the discrete function is used to ensure that force transmission is conserved, and the residual threshold is used to determine coupling convergence;

[0027] When the pipeline elastomechanics equation is coupled and converges, pipeline configuration indication information is output; the pipeline configuration indication information includes at least one of mining operation parameter adjustment and pipeline parameter adjustment.

[0028] The application further provides a pipeline configuration system in an ocean current, comprising:

[0029] A data acquisition module is configured to acquire ocean current data and determine flow velocity distribution of each flow layer of the ocean current data;

[0030] A first calculation module is configured to take the layered flow velocity field including the flow velocity distribution of each flow layer as an initial condition of the Navier-Stokes equation, and calculate a corresponding relationship between pipeline surface fluid velocity and pipeline surface displacement; the Navier-Stokes equation is used to describe the motion of fluid;

[0031] A second calculation module is configured to calculate a boundary source term according to the corresponding relationship between the pipeline surface fluid velocity and the pipeline surface displacement; the boundary source term is used to represent fluid reaction force caused by the motion of the pipeline surface;

[0032] A third calculation module is configured to construct a nonlinear elastic deformation model of the pipeline under deformation conditions; the nonlinear elastic deformation model is used to represent a pipeline stress tensor;

[0033] A coupling calculation module is configured to take the boundary source term as a pipeline surface force, combine the pipeline stress tensor, substitute into a pipeline elastomechanics equation, and use the immersed boundary method to couple and calculate the pipeline elastomechanics equation, iteratively update the flow velocity and the pipeline surface displacement, and obtain pipeline configuration indication information when the pipeline elastomechanics equation converges.

[0034] The application further provides a computer readable storage medium having a computer program stored thereon; the computer program is executed by a processor to implement the steps of the method described above.

[0035] The application further provides an electronic device comprising a memory and a processor; the memory has a computer program stored therein; the processor invokes the computer program in the memory to implement the steps of the method described above.

[0036] The application provides a pipeline configuration method in ocean current, comprising the following steps: obtaining ocean current data, and determining flow velocity distribution of each flow layer of the ocean current data; taking a layered flow velocity field containing the flow velocity distribution of each flow layer as an initial condition of Navier-Stokes equation, and calculating a corresponding relationship between pipeline surface fluid velocity and pipeline surface displacement; the Navier-Stokes equation is used to describe the motion of fluid; calculating a boundary source term according to the corresponding relationship between the pipeline surface fluid velocity and the pipeline surface displacement; the boundary source term is used to represent fluid reaction force caused by the movement of the pipeline surface; constructing a nonlinear elastic deformation model of the pipeline under deformation conditions, the nonlinear elastic deformation model is used to represent a pipeline stress tensor; taking the boundary source term as a pipeline surface force, combining the pipeline stress tensor into a pipeline elasticity mechanics equation, and calculating the pipeline elasticity mechanics equation by using an immersed boundary method, and iteratively updating the flow velocity and the pipeline surface displacement until the pipeline elasticity mechanics equation converges to obtain pipeline configuration indication information.

[0037] The application can accurately simulate the movement of fluid around the pipeline by establishing a layered flow velocity field, comprehensively considering the layered effect of the ocean current, taking the layered flow velocity field as the initial condition of the Navier-Stokes equation, and thus more truly reflecting the interaction between the fluid and the pipeline. Meanwhile, the boundary source term can accurately represent the fluid reaction force caused by the movement of the pipeline surface according to the relationship between the pipeline surface fluid velocity and the pipeline surface displacement. The nonlinear elastic deformation model of the pipeline under deformation conditions can well represent the pipeline stress tensor, so as to consider the nonlinear mechanical properties and complex deformation conditions of the pipeline material, and thus make the stress and deformation analysis of the pipeline under the action of the fluid more accurate. Finally, the immersed boundary method is used to take the boundary source term as the pipeline surface force, combine the pipeline stress tensor into the pipeline elasticity mechanics equation for coupled calculation, which can process the fluid and solid interaction problem under complex boundary conditions. Through iteratively updating the flow velocity and the pipeline surface displacement until the pipeline elasticity mechanics equation converges, accurate pipeline configuration indication information can be obtained, which provides an important reference for the design, installation and maintenance of the pipeline, and helps to optimize the performance and safety of the pipeline system.

[0038] The application also provides a pipeline configuration system in ocean current, a computer readable storage medium and an electronic device, which have the above beneficial effects, and details are not repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0039] 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 to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only belong to the embodiments of the present application, and those skilled in the art can also obtain other drawings according to the provided drawings without any creative labor.

[0040] Figure 1 A flow chart of a pipeline configuration method in ocean current provided by an embodiment of the present application;

[0041] Figure 2 A structural diagram of a pipeline configuration system provided by an embodiment of the present application;

[0042] Figure 3 A structural diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0043] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in a clear and complete manner with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0044] The object information involved in the present application includes but is not limited to object device information, object personal information, etc., and the data includes but is not limited to data for analysis, stored data, displayed data, etc., which are all information and data authorized by the object or fully authorized by all parties, and the collection, use and processing of the related data need to comply with the relevant laws, regulations and standards of countries and regions.

[0045] Reference is made to Figure 1 , Figure 1 A flow chart of a pipeline configuration method in ocean current provided by an embodiment of the present application, the method comprising:

[0046] S101: obtaining ocean current data and determining flow velocity distribution of each flow layer of the ocean current data;

[0047] S102: taking the layered flow velocity field containing the flow velocity distribution of each flow layer as an initial condition of Navier-Stokes equation to calculate the corresponding relationship between pipeline surface fluid velocity and pipeline surface displacement; the Navier-Stokes equation is used to describe the motion of fluid;

[0048] S103: calculating boundary source term according to the corresponding relationship between pipeline surface fluid velocity and pipeline surface displacement; the boundary source term is used to represent the fluid reaction force caused by the motion of the pipeline surface;

[0049] S104: constructing a nonlinear elastic deformation model of the pipeline under deformation condition, the nonlinear elastic deformation model is used to represent the stress tensor of the pipeline;

[0050] S105: The boundary source term is used as the pipe surface force. The pipe stress tensor is substituted into the pipe elasticity equation. The pipe elasticity equation is calculated by coupling the submerged boundary method. The flow velocity and pipe surface displacement are iteratively updated until the pipe elasticity equation converges to obtain the pipe configuration indication information.

[0051] In the dynamic analysis of deep-sea mining pipelines, the interaction between the fluid and the pipeline is achieved by coupling the fluid dynamics equations and the pipeline's elastic deformation equations. In this process, the fluid not only exerts pressure on the pipeline surface but also influences the pipeline's motion through friction. The fluid inside the pipeline (such as ore slurry) also affects the pipeline's deformation through viscosity and inertia.

[0052] The motion of the fluid is described by the Navier-Stokes equations. Let the fluid velocity field be , the fluid density be , the pressure be p, and the fluid viscosity be . The external disturbance force is... For incompressible fluids, the Navier-Stokes equations are:

[0053] ;

[0054] To adapt to the complex deep-sea environment, ocean currents not only face external disturbances but also require consideration of the stratification effect of current velocities at different depths. In the deep sea, ocean currents are typically divided into multiple distinct layers, each with varying current velocities and turbulence intensities. Therefore, fluid velocity can be represented using a stratified model, determining the velocity distribution of each layer in the ocean current data as follows:

[0055] ;

[0056] Where is the velocity distribution of the i-th layer, which is a time- and space-based perturbation function used to represent the ocean current dynamics of different flow layers.

[0057] The interaction between fluid and pipe affects fluid motion through forces applied to the pipe surface. At each point on the pipe surface, movement influences fluid flow; therefore, the coupling between the pipe and fluid needs to be addressed using the submerged boundary method (IBM). The fluid velocity on the pipe is matched with the displacement of the pipe surface:

[0058] ;

[0059] This equation describes the synchronization between the fluid velocity and the pipe displacement on the pipe surface. To incorporate the effect of the fluid motion on the pipe, the fluid dynamics equations need to include a boundary source term, which is determined by the fluid reaction force caused by the motion on the pipe surface:

[0060] ;

[0061] where F is the force on the pipe surface, is the Dirac delta function, and represents the influence of the force exerted by the pipe surface on the fluid velocity field.

[0062] The influence of the fluid inside the pipe on the pipe motion is described by the frictional force and inertial effects between the fluid and the pipe surface. The flow of the fluid inside the pipe follows similar equations as the external fluid, and the effect of friction is generally nonlinear, depending on the difference between the fluid velocity and the pipe displacement. The frictional force between the velocity field of the fluid inside the pipe and the displacement field of the pipe surface can be represented by the following equation:

[0063] ;

[0064] where is the friction coefficient, describing the nonlinear frictional force between the fluid and the pipe surface. This equation reflects the resistance of the fluid inside the pipe to the displacement of the pipe, especially when the difference between the fluid velocity and the pipe surface displacement is large, the frictional force increases significantly. The frictional force is input into the Navier-Stokes equation of the fluid as a boundary source term.

[0065] Frictional force is coupled to the fluid Navier-Stokes equation through the boundary source term Fboundary in the immersed boundary method (IBM), affecting the solution of the fluid velocity field . The reaction force of the fluid on the pipe is then substituted into the pipe elasticity equation in the following text through fs (pipe surface force).

[0066] When considering the elastic deformation of the pipe, especially in the case of large deformation, it is necessary to use the finite strain theory to describe the elastic behavior of the material. The traditional small deformation elastic theory is based on Hooke's law, which assumes that the strain is small, resulting in a linear relationship. However, in the case of large deformation and complex environment (such as the dynamic deformation of the pipe in deep sea environment), the linear elastic assumption cannot accurately describe the relationship between stress and strain.

[0067] Therefore, this application introduces a nonlinear elastic material model, especially a large deformation theory and an incompressible material model, as well as a high-order strain-displacement relationship to describe the nonlinear behavior of the material.

[0068] In the case of large deformation, the traditional small strain theory (such as linear elastic theory) cannot describe the influence of large deformation on the pipe. Therefore, the finite strain theory is introduced, which describes the large deformation problem by introducing the Lagrangian strain tensor and the Cauchy stress tensor. Assuming that the deformation of the pipe is from the initial configuration to the deformed configuration, the coupled deformation between the fluid and the pipe can be described by the following equation, the steps of which include:

[0069] Firstly, define the deformation gradient tensor of the pipe according to the initial coordinates and the deformed coordinates;

[0070] Secondly, calculate the Lagrangian strain tensor according to the unit matrix and the deformation gradient tensor; the Lagrangian strain tensor is used to represent the response of the pipe to the disturbance;

[0071] Thirdly, calculate the stress tensor of the pipe according to the deformation gradient tensor; the stress tensor is used to represent the stress state of the pipe during deformation;

[0072] Fourthly, establish the equivalent relationship between the stress tensor, the elastic tensor of the pipe material and the Lagrangian strain tensor, and obtain the nonlinear elastic deformation model of the pipe under the deformation condition.

[0073] Firstly, define the deformation gradient tensor F as the derivative of the deformation:

[0074] ;

[0075] Wherein, is the initial coordinate, is the deformed coordinate. Through the deformation gradient tensor, the strain tensor of the pipe can be described by the Lagrangian strain tensor:

[0076] ;

[0077] Wherein, is the unit matrix, is the Lagrangian strain tensor, which is used to describe the deformation degree of the pipe after deformation relative to the original shape, and quantifies the strain state of the pipe from the initial configuration to the deformed configuration. The strain tensor is the response of the pipe to the disturbance, rather than directly determining the disturbance. The disturbance acts on the pipe through fluid-structure coupling, causing the pipe to deform, and then the deformation degree is described by F and E, and the stress is calculated through the constitutive equation (such as Neo-Hookean model).

[0078] In order to consider the large deformation and strong nonlinear behavior of the pipe in the deep sea environment, a nonlinear material model is used to describe the relationship between the stress and strain of the pipe. Here, it is not limited to use which constitutive equation, Mooney-Rivlin model and Neo-Hookean model are commonly used nonlinear elastic material models, which are suitable for incompressible materials (such as metal materials of the pipe).

[0079] This embodiment takes the Neo-Hookean model as an example, which can accurately describe the nonlinear response of elastic materials in large deformation problems. For incompressible elastic body, the relationship between stress and strain can be written as:

[0080] ;

[0081] where, is the Cauchy stress tensor, describing the stress state of the pipe during large deformation, is the shear modulus of the material, is the Lamé constant of the material, is the deformation gradient tensor, is the identity tensor.

[0082] This nonlinear stress-strain relationship can effectively capture the elastic behavior of the pipe under large displacement and strong nonlinearity, especially in large-scale deformation caused by fluid disturbance.

[0083] The stress tensor calculated above can describe the response of the pipe under the action of ocean current disturbance and internal fluid friction in deep sea environment. In the case of large deformation, the stress state of the pipe not only depends on the shape of the pipe, but also depends on the dynamic behavior of the fluid inside the pipe.

[0084] Starting from the constitutive equation, the dynamic equation of the pipe under disturbance in deep sea can be derived. Due to the interaction between fluid and solid, the elastic deformation of the pipe is coupled with the stress transmission of the fluid:

[0085] ;

[0086] where, is the elastic tensor of the material, which depends on the properties of the pipe material, is the Lagrangian strain tensor, determined by the deformation gradient tensor .

[0087] In the case of large deformation, it is also necessary to consider the high-order strain-displacement relationship, which describes the influence of nonlinear deformation of the pipe on the displacement field, especially in the case of large angle rotation and large stretching. The high-order term of the strain-displacement relationship can be described by the second-order strain tensor:

[0088] ;

[0089] where, represents the second-order strain tensor of the pipe, which is used to describe the shear deformation and tensile deformation under large deformation; represents the gradient tensor of the displacement field u, which is used to describe the rate of change of displacement in space. In the process of large deformation calculation, reflects the local stretching and rotation of the material point, and is the basis for constructing the high-order strain tensor. Compared with the Lagrangian strain tensor E, the second-order strain tensor additionally considers Item, which is used to describe the nonlinear shear and rotational effects under large deformation. In the subsequent coupling calculation process, the second-order strain tensor can correct the stress calculation, making the constitutive equation more accurately capture the nonlinear response under large deformation. In addition, in the deformation transmission process of the fluid-structure coupling interface, the deformation calculated by the second-order strain tensor is mapped to the fluid grid through the displacement field in the IBM method, generating boundary source terms.

[0090] In deep-sea environments, pipelines not only undergo large displacements due to external ocean current disturbances but also experience mechanical effects due to fluid actions, such as ore slurry or seawater inside the pipeline. To simulate this coupling effect, the elastic deformation of the pipeline needs to be combined with fluid dynamics equations.

[0091] The elastic mechanics equation of the pipeline is:

[0092] ;

[0093] where is the density of the pipeline, is the displacement field of the pipeline, is the stress tensor of the pipeline, and is the external force caused by the fluid (such as friction and fluid pressure).

[0094] It should be noted that the strain tensor E is used to describe the degree of material deformation and is a geometric quantity calculated from the deformation gradient tensor F. The stress tensor σ is used to describe the internal force distribution of the material and is a mechanical quantity determined by the constitutive relationship. The two belong to different physical concepts, strain is the result of deformation, and stress is the internal force response caused by deformation. Under small deformation, stress and strain satisfy Hooke's law.

[0095] To solve the above nonlinear elastic equation, the present embodiment adopts the finite element method (FEM), which can handle complex geometric and material nonlinear problems. By dividing the pipeline into finite elements, the displacement field of each element is solved, and finally the deformation response of the entire pipeline is obtained.

[0096] In the dynamic analysis of deep-sea mining pipelines, the interaction between the fluid and the pipeline is crucial. Especially in deep-sea environments, the pipeline not only bears the pressure of external ocean current disturbances but also experiences the friction and inertial forces of internal fluids. To accurately simulate these interactions, the present method combines a nonlinear elastic mechanics model to describe the deformation of the pipeline and uses the immersed boundary method to handle the interaction between the fluid and the solid boundary.

[0097] Under this framework, first, the elastic deformation model of the pipeline needs to be established, especially the nonlinear deformation behavior under large deformation conditions. Then, the deformation information of the pipeline is coupled with the fluid dynamics equations through the immersed boundary method, and finally the complete coupling solution of the fluid and the pipeline is achieved. The following introduces the elastic deformation model of the pipeline and how to couple it with the fluid dynamics equations through the immersed boundary method.

[0098] In the interaction of fluid and pipe, the dynamics equation of fluid describes the motion of fluid, while the elastic deformation of pipe is described by the nonlinear elastic mechanics equation. In the coupling problem, the immersed boundary method provides an effective framework for dealing with the complex interaction between the fluid and the solid (pipe) boundary.

[0099] In the nonlinear coupling system, the interaction between fluid and pipe is highly nonlinear, so the solution of each time step involves the coupled solution of fluid dynamics equation and pipe elastic deformation equation. In this case, it is difficult to directly solve the nonlinear equation system, so the Newton-Raphson method is used to accelerate the iterative convergence in the embodiments of the present application.

[0100] The Newton-Raphson method is a numerical method based on Taylor series expansion, which gradually approaches the solution of the equation by iteration. The core idea is to linearize the nonlinear equation system and use the approximate value of the existing solution to calculate the new solution. This method is widely used in nonlinear coupling problems, especially in fluid-structure coupling problems, which can effectively accelerate the solution process.

[0101] Expansion and iteration of nonlinear coupling equation. Considering the nonlinear coupling system of fluid and pipe, the entire system can be regarded as a nonlinear equation system composed of two subsystems. There is a complex coupling relationship between the fluid equation (modified Navier-Stokes equation) and the pipe deformation equation (nonlinear elastic equation).

[0102] The embodiments of the present application consider the stratification effect of ocean currents by establishing a stratified flow field, which is used as the initial condition of the Navier-Stokes equation. The stratified flow field can accurately simulate the motion of fluid around the pipe, thereby more truly reflecting the interaction between fluid and pipe. At the same time, the boundary source term is calculated according to the relationship between the fluid velocity on the pipe surface and the pipe surface displacement, so that the boundary source term can accurately represent the fluid reaction force caused by the pipe surface motion. The nonlinear elastic deformation model of the pipe under deformation conditions is constructed, which can well represent the pipe stress tensor, thereby considering the nonlinear mechanical properties of the pipe material and the complex deformation conditions, making the stress and deformation analysis of the pipe under the action of fluid more accurate. Finally, the immersed boundary method is used to take the boundary source term as the pipe surface force, and the pipe stress tensor is substituted into the pipe elastic mechanics equation for coupling calculation, which can handle the interaction problem of fluid and solid under complex boundary conditions. By iteratively updating the flow velocity and pipe surface displacement, the pipe elastic mechanics equation converges, and the accurate pipe configuration indication information can be obtained, which provides an important reference for the design, installation and maintenance of the pipe configuration process, and helps to optimize the performance and safety of the pipe system.

[0103] Suppose that the fluid velocity field and pressure field in the current iteration are and the displacement field of the pipe is . We want to update these unknowns in the (k+1)th iteration to obtain the new fluid velocity field, pressure field and pipe displacement field.

[0104] According to the Newton-Raphson method, the nonlinear equation is linearized by performing a Taylor series expansion, and an updated formula is obtained. Suppose there is a nonlinear equation to be solved, with a Jacobian matrix of type JJ, represented as:

[0105] ;

[0106] Where is the residual of the current solution, is the Jacobian matrix, and is the update amount of the solution. By linearizing the equation, the iterative update formula is obtained:

[0107] ;

[0108] In the coupled problem of fluid and pipeline, the fluid equations and pipeline deformation equations are solved iteratively, respectively. For each time step, the following set of nonlinear equations needs to be solved:

[0109] ;

[0110] ;

[0111] Wherein, represents the nonlinear dynamic equation of the fluid. This represents the modified fluid dynamics equation.

[0112] The equation representing the nonlinear elastic deformation of the pipeline. This represents the nonlinear elastic deformation equation for the pipe. To couple these two equations, the boundary source terms of the fluid equation depend on the forces on the pipe surface (the pipe's deformation). Therefore, the fluid equation and the pipe deformation equation need to be updated simultaneously. and Coupling via the submerged boundary method (IBM):

[0113] Specifically, pipe deformation u s External force f induced by the fluid s Influence on the equation of nonlinear elastic deformation Fluid reaction force through Entering the nonlinear dynamic equation This leads to an iterative solution.

[0114] Step 1: Nonlinear iteration of the fluid equations:

[0115] For the fluid equation, the next fluid velocity and pressure fields are solved from the current velocity and pressure fields. First, the residual of the fluid equation is calculated, and then its Jacobian matrix is calculated, which represents the linearization of the fluid equation at the current iteration step:

[0116]

[0117] Then, the fluid velocity and pressure fields are iteratively updated using the Newton-Raphson method:

[0118]

[0119] Nonlinear iteration of the tube deformation equation. For the deformation equation of the tube, the displacement field of the tube is updated using the nonlinear elastic mechanics equation. First, the residual of the tube deformation equation is calculated, and then its Jacobian matrix is calculated, which represents the linearization of the tube deformation equation at the current iteration step:

[0120]

[0121] Next, the displacement field of the tube is iteratively updated using the Newton-Raphson method:

[0122]

[0123] Coupled iteration. Since the surface force of the tube will affect the velocity field of the fluid, and the change of the fluid velocity will affect the deformation of the tube, the solution of the fluid and the tube is coupled. In each iteration, first update the displacement field of the tube according to the current fluid state, then calculate the boundary source term according to the updated tube displacement, and finally bring the boundary source term back to the fluid equation for updating.

[0124] Specifically, the boundary source term calculated in the fluid equation depends on the force caused by the tube deformation. The force on the surface of the tube is calculated by the interaction of tube deformation and fluid friction, and then these forces are fed back to the fluid equation.

[0125] Each time the fluid velocity and tube displacement are updated, the two steps are alternately performed until the velocity field and displacement field of the fluid and tube converge, thereby obtaining the tube configuration indication information.

[0126] The following describes the present application in a specific application process of the present application:

[0127] ​​​​​Application of stratified current model. In deep-sea mining, the stratification effect of ocean currents directly affects the dynamic response of the pipeline. By using the stratified current model, the non-uniform load of the fluid on the pipeline at different depths can be accurately calculated. The specific application steps are as follows:

[0128] Flow layer parameterization:

[0129] According to the ocean observation data (such as ADCP measurement), the ocean current is divided into N layers, and the flow velocity distribution ui(z) of each layer is fitted by an exponential function or a logarithmic law, for example:

[0130] ;

[0131] The disturbance function uses a random fluctuation model (such as Gaussian white noise) to simulate turbulence.

[0132] Pipeline load mapping:

[0133] The stratified flow velocity field is taken as the initial condition of the Navier-Stokes equation to calculate the pressure distribution and shear force of the fluid on the pipeline.

[0134] Engineering application: In the pipeline design stage, the model is used to optimize the arrangement of the counterweight blocks to offset the transverse vortex-induced vibration (VIV) of specific flow layers.

[0135] Practical application of Neo-Hookean model;

[0136] The nonlinear elastic model is used to predict the stress concentration and fatigue life of the pipeline under large deformation, and the specific process is as follows:

[0137] Material parameter calibration: The shear modulus and Lame constant are determined through uniaxial tensile test of pipeline material, for example, the parameters of a certain deep-sea steel pipe:

[0138] ;

[0139] During stress-strain calculation and safety evaluation, the deformation gradient tensor (F) is substituted into the Neo-Hookean constitutive equation, and the Cauchy stress is output.

[0140] Engineering application: Implement the model in finite element software (such as ABAQUS) to simulate the buckling behavior of the pipeline under the impact of ocean currents. Combined with the Mises stress criterion, if (yield strength), an early warning is triggered and the pipeline wall thickness or material is adjusted.

[0141] The coupling solution process of immersed boundary method (IBM) is as follows:

[0142] Fluid-structure data transfer: pipe surface mesh node displacement Generate boundary source term by mapping to fluid mesh through interpolation function .

[0143] Key step: use discrete Dirac function Ensure the conservation of force transfer.

[0144] Iterative convergence control: set residual threshold , if , determine the coupling convergence. Engineering application: in real-time monitoring system, update the fluid-pipe coupling state every 0.1 seconds, dynamically adjust the mining system operation parameters (such as lifting speed).

[0145] See Figure 2 , Figure 2 A schematic diagram of a pipe configuration system in an ocean current provided by an embodiment of the application, the system comprising:

[0146] A data acquisition module for acquiring ocean current data and determining the flow velocity distribution of each flow layer of the ocean current data;

[0147] A first calculation module for calculating the corresponding relationship between the pipe surface fluid velocity and the pipe surface displacement by taking the layered flow velocity field containing the flow velocity distribution of each flow layer as the initial condition of the Navier-Stokes equation; the Navier-Stokes equation is used to describe the motion of fluid;

[0148] A second calculation module for calculating a boundary source term according to the corresponding relationship between the pipe surface fluid velocity and the pipe surface displacement; the boundary source term is used to represent the fluid reaction force caused by the movement of the pipe surface;

[0149] A third calculation module for constructing a nonlinear elastic deformation model of the pipe under deformation conditions, the nonlinear elastic deformation model being used to represent the pipe stress tensor;

[0150] A coupling calculation module for taking the boundary source term as the pipe surface force, combining the pipe stress tensor into the pipe elasticity mechanics equation, and using the immersed boundary method to couple the pipe elasticity mechanics equation to iteratively update the flow velocity and the pipe surface displacement until the pipe elasticity mechanics equation converges to obtain pipe configuration indication information.

[0151] The application also provides an embodiment corresponding to a computer readable storage medium. The computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the steps of the method as described in the above method embodiment.

[0152] It can be understood that if the method in the above embodiment is implemented in the form of a software function unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and performs all or part of the steps of the method described in each embodiment of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic disk or an optical disk, and various program code storage media.

[0153] The computer readable storage medium provided by the embodiment includes the method mentioned above, and the effects are the same as above.

[0154] The present application also provides an electronic device, referring to Figure 3 , the structural diagram of an electronic device provided by the embodiment of the present application, as shown in Figure 3 , can include a processor 1410 and a memory 1420.

[0155] The processor 1410 can include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 1410 can be implemented in at least one hardware form of a DSP (Digital Signal Processing), a FPGA (Field-Programmable Gate Array), and a PLA (Programmable Logic Array). The processor 1410 can also include a main processor and a coprocessor. The main processor is a processor for processing data in an awake state, also known as a CPU (Central Processing Unit). The coprocessor is a low-power processor for processing data in a standby state. In some embodiments, the processor 1410 can be integrated with a GPU (Graphics Processing Unit) that is responsible for rendering and drawing the content to be displayed by the display screen. In some embodiments, the processor 1410 can also include an AI (Artificial Intelligence) processor for processing machine learning-related computing operations.

[0156] The memory 1420 can include one or more computer-readable storage media. The computer-readable storage media can be non-transitory. The memory 1420 can also include high-speed random access memory and can include nonvolatile memory, such as one or more magnetic disk storage devices, optical storage devices, flash memory devices, or other nonvolatile solid-state storage devices. In this embodiment, the memory 1420 is at least used to store the following computer programs 1421, wherein the computer programs are loaded and executed by the processor 1410, and can realize the related steps in the method executed by the electronic device side disclosed in any of the preceding embodiments. In addition, the resources stored in the memory 1420 can also include an operating system 1422, data 1423, and the like, and the storage mode can be temporary storage or permanent storage. The operating system 1422 can include Windows, Linux, Android, and the like.

[0157] In some embodiments, the electronic device can further include a display screen 1430, an input / output interface 1440, a communication interface 1450, a sensor 1460, a power supply 1470, and a communication bus 1480.

[0158] Of course, Figure 3 The structure of the electronic device shown does not constitute a limitation on the electronic device in the embodiments of the present application. In actual applications, the electronic device can include more or fewer components than those shown, or some components can be combined. Figure 3 The structure of the electronic device shown does not constitute a limitation on the electronic device in the embodiments of the present application. In actual applications, the electronic device can include more or fewer components than those shown, or some components can be combined.

[0159] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system provided by the embodiments, since it corresponds to the method provided by the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0160] The principles and implementation manners of the present application are described by using specific examples in this paper. The above description of the embodiments is only used to help understand the method and its core idea of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the present application.

[0161] It also needs to be explained that in the present specification, the relational terms such as first and second and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

Claims

1. A method for configuring pipelines in ocean currents, characterized in that, include: Acquire ocean current data and determine the velocity distribution of each current layer in the ocean current data; The stratified velocity field, which includes the velocity distribution of each flow layer, is used as the initial condition for the Navier-Stokes equations to calculate the correspondence between the fluid velocity and the displacement on the pipe surface; the Navier-Stokes equations are used to describe the motion of the fluid. The boundary source term is calculated based on the correspondence between the fluid velocity and the displacement on the pipe surface; the boundary source term is used to characterize the fluid reaction force caused by the motion on the pipe surface. A nonlinear elastic deformation model of the pipeline under deformation conditions is constructed, and the nonlinear elastic deformation model is used to characterize the pipeline stress tensor. The boundary source term is used as the pipe surface force. The pipe stress tensor is substituted into the pipe elasticity equation. The pipe elasticity equation is calculated by coupling the submerged boundary method. The flow velocity and pipe surface displacement are iteratively updated until the pipe elasticity equation converges to obtain the pipe configuration indication information. The nonlinear elastic deformation model of the pipeline under deformation conditions includes: The deformation gradient tensor of the pipeline is defined based on the initial coordinates and the coordinates after deformation. The Lagrange strain tensor is calculated based on the identity matrix and the deformation gradient tensor; the Lagrange strain tensor is used to characterize the pipeline's response to disturbances. The stress tensor of the pipeline is calculated based on the deformation gradient tensor; the stress tensor is used to characterize the stress state of the pipeline during the deformation process. By establishing the equivalent relationship between the stress tensor, the elastic tensor of the pipeline material, and the Lagrange strain tensor, a nonlinear elastic deformation model of the pipeline under deformation conditions is obtained.

2. The method according to claim 1, characterized in that, Determining the velocity distribution of each current layer in the ocean current data includes: The velocity distribution of each flow layer in the ocean current data is fitted by an exponential function or a logarithmic law, and turbulence in the ocean current data is simulated by a perturbation function.

3. The method according to claim 1, characterized in that, When determining the relationship between fluid velocity and displacement on the pipe surface, it also includes: The nonlinear frictional force between the velocity field of the fluid inside the pipe and the displacement field of the pipe surface is calculated based on the friction coefficient. The nonlinear frictional force is added to the boundary source term to couple it into the Navier-Stokes equations.

4. The method according to claim 1, characterized in that, Calculating the stress tensor of the pipeline based on the deformation gradient tensor includes: The stress tensor of the pipeline is calculated based on the deformation gradient tensor, the Lamé constant of the pipeline material, the unit tensor, and the shear modulus of the pipeline material.

5. The method according to claim 1 or 4, characterized in that, When constructing a nonlinear elastic deformation model of a pipeline under deformation conditions, the following are also included: The second-order strain tensor of the pipeline is calculated based on the gradient tensor of the displacement field; the second-order strain tensor is used to describe the nonlinear shear and rotation effects of the pipeline during deformation, in order to correct the stress tensor.

6. The method according to claim 1, characterized in that, The pipeline elasticity equations are calculated using the submerged boundary method, and the flow velocity and pipeline surface displacement are iteratively updated until the pipeline elasticity equations converge. The resulting pipeline configuration indication information includes: The displacements of the surface grid nodes of the pipeline are mapped to the layered velocity field using an interpolation function to obtain the boundary source term; Add a discrete function and set a residual threshold; the discrete function is used to ensure force transmission conservation, and the residual threshold is used to determine coupling convergence. When the pipeline elasticity equations converge, pipeline configuration indication information is output; the pipeline configuration indication information includes at least one of mining operation parameter adjustment and pipeline parameter adjustment.

7. A pipeline configuration system in an ocean current, characterized in that, include: The data acquisition module is used to acquire ocean current data and determine the velocity distribution of each current layer in the ocean current data. The first calculation module is used to use the stratified velocity field containing the velocity distribution of each flow layer as the initial condition for the Navier-Stokes equations to calculate the correspondence between the fluid velocity on the pipe surface and the displacement on the pipe surface; the Navier-Stokes equations are used to describe the motion of the fluid. The second calculation module is used to calculate the boundary source term based on the correspondence between the fluid velocity and the displacement of the pipe surface; the boundary source term is used to characterize the fluid reaction force caused by the motion of the pipe surface. The third calculation module is used to construct a nonlinear elastic deformation model of the pipeline under deformation conditions. The nonlinear elastic deformation model is used to characterize the pipeline stress tensor. The coupled calculation module is used to take the boundary source term as the pipe surface force, combine it with the pipe stress tensor and substitute it into the pipe elasticity equation, use the submerged boundary method to coupled calculate the pipe elasticity equation, iteratively update the flow velocity and pipe surface displacement, until the pipe elasticity equation converges and the pipe configuration indication information is obtained. The process by which the third calculation module constructs a nonlinear elastic deformation model of the pipeline under deformation conditions includes: The deformation gradient tensor of the pipeline is defined based on the initial coordinates and the coordinates after deformation. The Lagrange strain tensor is calculated based on the identity matrix and the deformation gradient tensor; the Lagrange strain tensor is used to characterize the pipeline's response to disturbances. The stress tensor of the pipeline is calculated based on the deformation gradient tensor; the stress tensor is used to characterize the stress state of the pipeline during the deformation process. By establishing the equivalent relationship between the stress tensor, the elastic tensor of the pipeline material, and the Lagrange strain tensor, a nonlinear elastic deformation model of the pipeline under deformation conditions is obtained.

8. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor for executing the computer program to implement the steps of the method as claimed in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, implements the steps of the method as described in any one of claims 1 to 6.

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