Moon pool and platform coupled hydrodynamic calculation method, device, medium and equipment

Abstract

The invention relates to a moon pool and platform coupled hydrodynamic calculation method and device, a medium and equipment. The method comprises the following steps: establishing a platform model without a moon pool; solving the space velocity potential of the flow field in the platform model; inputting physical attribute parameters of a mooring and riser system into the platform model, establishing a platform mooring system model, and completing initialization; solving wave force, mooring tension and riser acting force of each order borne by the platform model under the initial time step length; solving a platform coupling motion equation of the platform model, which does not contain the acting force of fluid in the moon pool, and obtaining six-degree-of-freedom motion displacement of the platform model; completing initialization of a flow field; assigning the six-degree-of-freedom motion displacement of the platform model as the six-degree-of-freedom motion of the overlapped grid region; solving nonlinear motion of a water body in the moon pool, and obtaining parameters including fluid pressure to obtain fluid acting force in the moon pool; and solving a time domain motion equation of coupling of the moon pool and the platform, and carrying out repeated iteration until the last step of time calculation is completed.

Description

Technical Field

[0001] The invention relates to a method, device, medium and equipment for calculating hydrodynamic force of a moon pool and a platform coupling, belonging to the technical field of hydrodynamic force calculation of marine structures. Background Art

[0002] In order to meet the needs of offshore operations such as oil and gas resource development, marine minerals and marine scientific investigations, moon pools are widely used in marine engineering structures such as oil and gas exploration platforms, drilling ships, and deep-sea Spar platforms. Their main function is to provide a lowering and operating channel for important underwater equipment such as drilling platforms and drilling risers, tensioned production risers (TTRs), wellhead blowout preventers (BOPs) and Christmas trees.

[0003] The water inside the moon pool is connected to the outside seawater. The movement of the water inside the moon pool is affected by external excitation. Under some special resonance conditions, violent movement may occur, and its vertical climbing height may even reach three to four times the external environmental wave height. This strong resonance of the water inside the moon pool will not only cause slamming on the equipment and hull structure in the moon pool, but also cause extreme phenomena such as waves on the working deck at the edge of the moon pool, which seriously threatens the safety of personnel and equipment. The hydrodynamic coupling effect between the moon pool and the platform may aggravate its heaving and swaying motion, resulting in a sharp decline in the platform's motion performance.

[0004] At present, in the preliminary stage of hydrodynamic design, the traditional linear potential flow theory is used to obtain the overall hydrodynamic performance of the moon pool and the platform. However, under resonance conditions, that is, when the water inside the moon pool moves violently, the linear potential flow theory cannot take into account the nonlinear characteristics of the fluid response in the moon pool, and the prediction results may have large deviations, and the coupled hydrodynamic characteristics of the moon pool and the platform are also unknown.

[0005] How to accurately predict the nonlinear hydrodynamic response of the coupling between the water inside the moon pool and the platform, improve the motion performance of the floating platform, and suppress the resonance of the moon pool water to meet the needs of dry tree mining is the focus and difficulty of the current marine engineering field. Summary of the invention

[0006] In view of the above technical problems, the present invention provides a hydrodynamic calculation method, device, medium and equipment for the coupling of the moon pool and the platform. The method combines viscous computational fluid dynamics and potential flow theory methods, considers the complex motion characteristics of the fluid response in the moon pool, and realizes the coupled calculation of the moon pool and the platform motion, which can effectively solve the current nonlinear hydrodynamic problem of the coupling between the water body inside the moon pool and the platform system.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A hydrodynamic calculation method for coupling a moon pool with a platform, comprising:

[0009] S1: Based on the three-dimensional potential flow theory, a platform model without a moon pool is established, environmental parameters are set, the surface boundary grid of the platform model is divided, and the main scale parameters are input into the platform model;

[0010] S2: Based on S1, the spatial velocity potential of the flow field in the platform model is solved to obtain the mass matrix, damping matrix, and platform stiffness matrix. According to the mass matrix, damping matrix, and platform stiffness matrix, the frequency domain hydrodynamic coefficient and motion response amplitude RAO of the platform model are obtained;

[0011] S3: inputting physical property parameters of the mooring and riser systems into the platform model, establishing a platform mooring system model, completing initialization, and obtaining an initialized platform mooring system model;

[0012] S4: Input parameters into the platform model and combine the initial platform mooring system model, frequency domain hydrodynamic coefficients and motion response amplitude RAO to solve the various order wave forces, mooring tension and riser force on the platform model at the initial time step;

[0013] S5: Based on the various order wave forces, mooring tension and riser forces in S4, the platform coupled motion equations of the platform model excluding the fluid forces in the moon pool are solved to obtain the six-degree-of-freedom motion displacement of the platform model;

[0014] S6: Based on the computational fluid dynamics method, construct a three-dimensional numerical water pool for viscous flow, divide the computational domain into grids, specify overlapping grid areas, define the finite volume method spatial discretization format, time discretization format, velocity-pressure coupling algorithm, define boundary conditions, and complete the initialization of the flow field;

[0015] S7: The six-degree-of-freedom motion displacement of the platform model is specified as the six-degree-of-freedom motion of the overlapping grid area;

[0016] S8: Based on S6 and S7, solve the nonlinear motion of the water in the moon pool, obtain parameters including fluid pressure, and integrate the pressure on the inner wall of the moon pool to obtain the fluid force in the moon pool;

[0017] S9: Perform the next time step iteration, repeat S4, and add the fluid force in the moon pool calculated in S8 to the time domain motion equation of the moon pool and platform coupling, solve the time domain motion equation of the moon pool and platform coupling, obtain the platform displacement, and iterate repeatedly until the last time calculation step is completed.

[0018] In the hydrodynamic calculation method for coupling the moon pool with the platform, preferably, in S1, the three-dimensional potential flow theory assumes that the fluid is an ideal fluid without viscosity, rotation, or compression, and the main scale parameters include the weight, center of gravity, and radius of inertia of the platform.

[0019] In the hydrodynamic calculation method for coupling the moon pool and the platform, preferably, in S2, the spatial velocity potential of the flow field includes incident potential, radiation potential and diffraction potential, which are specifically as follows:

[0020]

[0021] In the formula, is the total velocity potential; is the incident potential; is the radiation potential; is the diffraction potential; v j is the motion amplitude of the j-degree of freedom; j is the j-degree of freedom of the floating body. The hydrodynamic calculation method for the coupling of the moon pool and the platform is preferably, in S6, the computational fluid dynamics method is the Reynolds averaged Navier-Stokes equation method, which is as follows:

[0022]

[0023] In the formula, u i is the average velocity component; x i is the Cartesian coordinate value; t is time; p is pressure; μ is dynamic viscosity; μ' i ,μ' j The hydrodynamic calculation method for coupling the moon pool and the platform is preferably such that, in S6, the Reynolds-averaged Navier-Stokes equations are discretized using the finite volume method, the spatial discretization format uses the second-order upwind discretization format, the time discretization uses the implicit non-steady-state second-order time format, and the velocity-pressure coupling calculation uses the SIMPLE algorithm.

[0024] In the hydrodynamic calculation method for coupling the moon pool and the platform, preferably, in S6, initializing the flow field comprises the following specific steps:

[0025] Construct the computational domain of the viscous flow three-dimensional numerical water pool, establish the platform solid wall boundary including the moon pool, and set the boundary conditions around the numerical water pool as solid wall boundaries;

[0026] The volume of fluid function (VOF) method is used to capture the flow field characteristics of the free liquid surface.

[0027] The overlapping grid method is used to solve the grid division problem of the complex platform structure including the moon pool, realize the information transfer between the moving area and the background grid, and complete the flow field initialization.

[0028] In the hydrodynamic calculation method for coupling the moon pool and the platform, preferably, in S9, the calculated internal forces of the moon pool are added to the total time domain motion equation of the platform through coordinate system conversion, so as to establish the coupling motion equation of the moon pool and the platform in the full time domain:

[0029]

[0030] In the formula, M and a ij are the mass matrix and the additional mass matrix respectively; X is the displacement matrix; K is the delay function matrix; C ij is the hydrostatic restoring force matrix; τ is the time-delay integral variable; t is time; F wave (t) is the first-order and second-order wave loads, F wind (t) is the wind load, F current (t) is the flow load, F moor (t) is the mooring force, F moonpool (t) is the fluid force in the moon pool.

[0031] A second aspect of the present invention provides a hydrodynamic calculation device for coupling a moon pool with a platform, comprising:

[0032] The first processing unit is used to establish a platform model without a moon pool based on the three-dimensional potential flow theory, set environmental parameters, divide the surface boundary grid of the platform model, and input main scale parameters into the platform model;

[0033] The second processing unit is used to solve the spatial velocity potential of the flow field in the platform model based on the first processing unit, obtain the mass matrix, the damping matrix, and the platform stiffness matrix, and obtain the frequency domain hydrodynamic coefficient and the motion response amplitude RAO of the platform model according to the mass matrix, the damping matrix, and the platform stiffness matrix;

[0034] The third processing unit inputs physical property parameters of the mooring and riser systems into the platform model, establishes a platform mooring system model, completes initialization, and obtains an initialized platform mooring system model;

[0035] The fourth processing unit inputs parameters into the platform model and combines the initial platform mooring system model, frequency domain hydrodynamic coefficients and motion response amplitude RAO to solve the various order wave forces, mooring tension and riser force on the platform model at the initial time step;

[0036] A fifth processing unit is used to solve the platform coupled motion equation of the platform model excluding the fluid force in the moon pool based on the various order wave forces, mooring tension and riser force in the fourth processing unit, and obtain the six-degree-of-freedom motion displacement of the platform model;

[0037] The sixth processing unit is used to construct a viscous flow three-dimensional numerical water pool based on the computational fluid dynamics method, divide the computational domain grid, specify the overlapping grid area, define the finite volume method space discretization format, time discretization format, velocity-pressure coupling algorithm, define boundary conditions, and complete the initialization of the flow field;

[0038] A seventh processing unit, for specifying the six-degree-of-freedom motion displacement of the platform model as the six-degree-of-freedom motion of the overlapping grid area;

[0039] an eighth processing unit, for solving the nonlinear motion of the water body in the moon pool based on the sixth processing unit and the seventh processing unit, obtaining parameters including fluid pressure, and integrating the pressure on the inner wall of the moon pool to obtain the fluid force in the moon pool;

[0040] The ninth processing unit is used to iterate the next time step, repeat the fourth processing unit, and add the fluid force in the moon pool calculated by the eighth processing unit to the time domain motion equation of the moon pool and platform coupling, solve the time domain motion equation of the moon pool and platform coupling, obtain the platform displacement, and iterate repeatedly until the last time calculation step is completed.

[0041] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any one of the above-mentioned methods for calculating the hydrodynamics of the moon pool and the platform coupling.

[0042] A fourth aspect of the present invention provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of any one of the above-mentioned methods for calculating the hydrodynamics of the moon pool and the platform coupling are implemented.

[0043] The present invention adopts the above technical solution, which has the following advantages:

[0044] 1. The present invention combines the advantages of computational fluid dynamics (CFD) method and potential flow theory. The method can solve the motion characteristics of the platform as a whole system under the coupling state of complex systems such as mooring, riser, moon pool, etc., solve the problem that CFD method is difficult to solve multi-scale models at the same time, and improve the overall calculation efficiency.

[0045] 2. The present invention solves the complex dynamic response problems of the water body inside the moon pool that cannot be considered by the existing linear potential flow theory, such as the superposition of different motion types and modes, the instantaneous rollover deformation of the free liquid surface and the vortex shedding near the wall, and can accurately predict the complex motion of the fluid in the moon pool and its force on the platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic flow chart of a method for calculating the hydrodynamic force of the moon pool and platform coupling provided in one embodiment of the present invention;

[0047] Figure 2 A schematic diagram of the overall system of the platform coupled with mooring cables, risers and moon pool provided in this embodiment of the present invention;

[0048] Figure 3 A schematic diagram of the moon pool and platform coupling calculation domain and boundaries provided in this embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work are within the scope of protection of the present invention.

[0050] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second", "third", "fourth" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0051] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside", "outside", "inner side", "outer side", "below", "above", etc. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures.

[0052] The existing computational fluid dynamics (CFD) numerical calculation method can only predict the movement of the platform system and the rise of the moon pool wave surface when the platform system is relatively simple, and cannot consider the coupling of complex systems such as mooring, riser, and moon pool, and the calculation efficiency is low. The existing potential flow theory calculation method, the linear potential flow theory cannot consider the nonlinear characteristics of the fluid response in the moon pool, and the prediction results may have large deviations, and the hydrodynamic characteristics of the coupling between the moon pool and the platform are unknown.

[0053] Based on the above technical problems, the present invention provides a hydrodynamic calculation method for the coupling of the moon pool and the platform. The method combines viscous computational fluid dynamics and potential flow theory methods, takes into account the complex motion characteristics of the fluid response in the moon pool, and realizes the coupled calculation of the moon pool and platform motion. It can effectively solve the current nonlinear hydrodynamic problem of the coupling between the water body inside the moon pool and the platform system.

[0054] like Figure 1 As shown, the hydrodynamic calculation method for coupling the moon pool and the platform provided by the present invention includes the following specific steps:

[0055] S1: Based on the three-dimensional potential flow theory, assuming that the fluid is an ideal fluid without viscosity, rotation, and compressibility, a platform model without a moon pool is established, environmental parameters such as water depth are set, the platform surface boundary grid is divided, and the main scale parameters such as platform weight, center of gravity, and radius of inertia are input.

[0056] The spatial velocity potential in the flow field is split into incident potential, radiation potential and diffraction potential:

[0057]

[0058] In the formula, is the total velocity potential; is the incident potential; is the radiation potential; is the diffraction potential; v j is the motion amplitude of the j-degree of freedom; j is the j-degree of freedom of the floating body. S2: Based on S1, the constant boundary element method is used to solve the spatial velocity potential of the flow field in the platform model to obtain the mass matrix, damping matrix, and platform stiffness matrix. According to the mass matrix, damping matrix, platform stiffness matrix, etc., the frequency domain hydrodynamic coefficients such as the platform added mass and radiation damping and the motion response amplitude RAO are obtained.

[0059] S3: Input the coordinates of the mooring system’s fairlead and anchor point, the material, diameter, length, The platform mooring system model is established by considering the main physical properties such as weight and stiffness. Depth, wind load coefficient, flow load coefficient, hydrodynamic parameters, etc., input wave parameters of regular waves or irregular waves, including wave spectrum, period, wave height, etc.

[0060] S4: Input the hydrodynamic parameters into the platform model and combine the initialized platform mooring system model, frequency domain hydrodynamic coefficients and motion response amplitude RAO to solve the various order wave forces, mooring tension and riser force acting on the platform model at the initial time step.

[0061] S5: Based on the various order wave forces, mooring tension and riser forces in S4, the platform coupled motion equations of the platform model excluding the fluid forces in the moon pool are solved to obtain the six-degree-of-freedom motion displacement of the platform model.

[0062] S6: Based on the computational fluid dynamics method, construct a three-dimensional numerical water pool for viscous flow, divide the computational domain into grids, specify overlapping grid areas, define the finite volume method spatial discretization format, time discretization format, velocity-pressure coupling algorithm, define boundary conditions, and complete the initialization of the flow field.

[0063] The computational fluid dynamics method is to use the Reynolds-averaged Navier-Stokes equation method, as follows:

[0064]

[0065] In the formula, u iis the average velocity component; x i is the Cartesian coordinate value; t is time; p is pressure; μ is dynamic viscosity; μ i ', j 'Pulsating velocity component. In S6, the finite volume method is used to discretize the Reynolds-averaged Navier-Stokes equations, the second-order upwind discretization format is used for spatial discretization, the implicit unsteady second-order time format is used for time discretization, and the SIMPLE algorithm is used for velocity-pressure coupling calculation.

[0066] Flow field initialization includes the following steps:

[0067] Construct the computational domain of the viscous flow three-dimensional numerical water pool, establish the platform solid wall boundary including the moon pool, and set the boundary conditions around the numerical water pool as solid wall boundaries;

[0068] The volume of fluid function (VOF) method is used to capture the flow field characteristics of the free liquid surface.

[0069] The overlapping grid method is used to solve the grid division problem of the complex platform structure including the moon pool and realize the motion The information between the region and the background grid is transferred to complete the flow field initialization.

[0070] S7: The six-degree-of-freedom motion displacement of the platform model is specified as the six-degree-of-freedom motion of the overlapping mesh area.

[0071] S8: Based on S6 and S7, solve the nonlinear motion of the water in the moon pool, obtain parameters including fluid pressure, and integrate the pressure on the inner wall of the moon pool to obtain the fluid force in the moon pool;

[0072] S9: Perform the next time step iteration, repeat S4, and add the fluid force in the moon pool calculated in S8 to the time domain motion equation of the moon pool and platform coupling, solve the time domain motion equation of the moon pool and platform coupling, obtain the platform displacement, and iterate repeatedly until the last time calculation step is completed.

[0073] In S9, the calculated forces in the moon pool are added to the total time domain motion equation of the platform through coordinate system conversion, and the coupled motion equation of the moon pool and the platform in the full time domain is established:

[0074]

[0075] In the formula, M and a ij are the mass matrix and the additional mass matrix respectively; X is the displacement matrix; K is the delay function matrix; C ij is the hydrostatic restoring force matrix; τ is the time-delay integral variable; t is time; F wave (t) is the first-order and second-order wave loads, F wind (t) is the wind load, F current (t) is the flow load, F moor (t) is the mooring force, Fmoonpool (t) is the fluid force in the moon pool.

[0076] A second aspect of the present invention provides a hydrodynamic calculation device for coupling a moon pool with a platform, comprising:

[0077] The first processing unit is used to establish a platform model without a moon pool based on the three-dimensional potential flow theory, set environmental parameters, divide the surface boundary grid of the platform model, and input main scale parameters into the platform model;

[0078] The second processing unit is used to solve the spatial velocity potential of the flow field in the platform model based on the first processing unit, obtain the mass matrix, the damping matrix, and the platform stiffness matrix, and obtain the frequency domain hydrodynamic coefficient and the motion response amplitude RAO of the platform model according to the mass matrix, the damping matrix, and the platform stiffness matrix;

[0079] The third processing unit inputs physical property parameters of the mooring and riser systems into the platform model, establishes a platform mooring system model, completes initialization, and obtains an initialized platform mooring system model;

[0080] The fourth processing unit inputs parameters into the platform model and combines the initial platform mooring system model, frequency domain hydrodynamic coefficients and motion response amplitude RAO to solve the various order wave forces, mooring tension and riser force on the platform model at the initial time step;

[0081] A fifth processing unit is used to solve the platform coupled motion equation of the platform model excluding the fluid force in the moon pool based on the various order wave forces, mooring tension and riser force in the fourth processing unit, and obtain the six-degree-of-freedom motion displacement of the platform model;

[0082] The sixth processing unit is used to construct a viscous flow three-dimensional numerical water pool based on the computational fluid dynamics method, divide the computational domain grid, specify the overlapping grid area, define the finite volume method space discretization format, time discretization format, velocity-pressure coupling algorithm, define boundary conditions, and complete the initialization of the flow field;

[0083] A seventh processing unit, for specifying the six-degree-of-freedom motion displacement of the platform model as the six-degree-of-freedom motion of the overlapping grid area;

[0084] an eighth processing unit, for solving the nonlinear motion of the water body in the moon pool based on the sixth processing unit and the seventh processing unit, obtaining parameters including fluid pressure, and integrating the pressure on the inner wall of the moon pool to obtain the fluid force in the moon pool;

[0085] The ninth processing unit is used to iterate the next time step, repeat the fourth processing unit, and add the fluid force in the moon pool calculated by the eighth processing unit to the time domain motion equation of the moon pool and platform coupling, solve the time domain motion equation of the moon pool and platform coupling, obtain the platform displacement, and iterate repeatedly until the last time calculation step is completed.

[0086] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any one of the above-mentioned methods for calculating the hydrodynamics of the moon pool and the platform coupling.

[0087] A fourth aspect of the present invention provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of any one of the above-mentioned methods for calculating the hydrodynamics of the moon pool and the platform coupling are implemented.

[0088] The present invention is described in terms of flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to specific embodiments. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0089] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0090] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the hydrodynamics of a moon pool coupled with a platform, characterized in that: include: S1: Based on the three-dimensional potential flow theory, a platform model without a moon pool is established, environmental parameters are set, the surface boundary grid of the platform model is divided, and the main scale parameters are input into the platform model; S2: Based on S1, the spatial velocity potential of the flow field in the platform model is solved to obtain the mass matrix, damping matrix, and platform stiffness matrix. According to the mass matrix, damping matrix, and platform stiffness matrix, the frequency domain hydrodynamic coefficient and motion response amplitude RAO of the platform model are obtained; S3: inputting physical property parameters of the mooring and riser systems into the platform model, establishing a platform mooring system model, completing initialization, and obtaining an initialized platform mooring system model; S4: Input the hydrodynamic parameters into the platform model and combine the initial platform mooring system model, frequency domain hydrodynamic coefficients and motion response amplitude RAO to solve the various order wave forces, mooring tension and riser force on the platform model at the initial time step; S5: Based on the various order wave forces, mooring tension and riser forces in S4, the platform coupled motion equations of the platform model excluding the fluid forces in the moon pool are solved to obtain the six-degree-of-freedom motion displacement of the platform model; S6: Based on the computational fluid dynamics method, construct a three-dimensional numerical water pool for viscous flow, divide the computational domain into grids, specify overlapping grid areas, define the finite volume method spatial discretization format, time discretization format, velocity-pressure coupling algorithm, define boundary conditions, and complete the initialization of the flow field; S7: The six-degree-of-freedom motion displacement of the platform model is specified as the six-degree-of-freedom motion of the overlapping grid area; S8: Based on S6 and S7, solve the nonlinear motion of the water in the moon pool, obtain parameters including fluid pressure, and integrate the pressure on the inner wall of the moon pool to obtain the fluid force in the moon pool; S9: Perform the next time step iteration, repeat S4, and add the fluid force in the moon pool calculated in S8 to the time domain motion equation of the moon pool and platform coupling, solve the time domain motion equation of the moon pool and platform coupling, obtain the platform displacement, and iterate repeatedly until the last time calculation step is completed.

2. The hydrodynamic calculation method for coupling the moon pool and the platform according to claim 1, characterized in that: In S1, the three-dimensional potential flow theory assumes that the fluid is an ideal fluid with no viscosity, no rotation, and no compression, and the main scale parameters include the platform weight, center of gravity, and radius of inertia.

3. The hydrodynamic calculation method for coupling the moon pool and the platform according to claim 1, characterized in that: In S2, the spatial velocity potential of the flow field includes incident potential, radiation potential and diffraction potential, as follows: In the formula, is the total velocity potential; is the incident potential; is the radiation potential; is the diffraction potential; v j is the motion amplitude of the j-degree of freedom; j is the j-degree of freedom of the floating body.

4. The hydrodynamic calculation method for coupling the moon pool and the platform according to claim 1, characterized in that: In S6, the computational fluid dynamics method adopts the Reynolds-averaged Navier-Stokes equation method, which is as follows: In the formula, u i is the average velocity component; x i is the Cartesian coordinate value; t is the time; p is pressure; μ is dynamic viscosity; μ' i ,μ' j Pulsating velocity component.

5. The hydrodynamic calculation method for coupling the moon pool and the platform according to claim 4, characterized in that: In S6, the finite volume method is used to discretize the Reynolds-averaged Navier-Stokes equations, the second-order upwind discretization format is used for spatial discretization, the implicit unsteady second-order time format is used for time discretization, and the SIMPLE algorithm is used for velocity-pressure coupling calculation.

6. The hydrodynamic calculation method for coupling the moon pool and the platform according to claim 5, characterized in that: In S6, initializing the flow field includes the following specific steps: Construct the computational domain of the viscous flow three-dimensional numerical water pool, establish the platform solid wall boundary including the moon pool, and set the boundary conditions around the numerical water pool as solid wall boundaries; The volume of fluid function (VOF) method is used to capture the flow field characteristics of the free liquid surface. The overlapping grid method is used to solve the grid division problem of the complex platform structure including the moon pool, realize the information transfer between the moving area and the background grid, and complete the flow field initialization.

7. The hydrodynamic calculation method for coupling the moon pool and the platform according to claim 1, characterized in that: In S9, the calculated forces in the moon pool are added to the total time domain motion equation of the platform through coordinate system conversion, and the coupled motion equation of the moon pool and the platform in the full time domain is established: In the formula, M and a ij are the mass matrix and the additional mass matrix respectively; X is the displacement matrix; K is the delay function matrix; C ij is the hydrostatic restoring force matrix; τ is the time-delay integral variable; t is time; F wave (t) is the first-order and second-order wave loads, F wind (t) is the wind load, F current (t) is the flow load, F moor (t) is the mooring force, F moonpool (t) is the fluid force in the moon pool.

8. A hydrodynamic calculation device for coupling a moon pool with a platform, characterized in that: include: The first processing unit is used to establish a platform model without a moon pool based on the three-dimensional potential flow theory, set environmental parameters, divide the surface boundary grid of the platform model, and input main scale parameters into the platform model; The second processing unit is used to solve the spatial velocity potential of the flow field in the platform model based on the first processing unit, obtain the mass matrix, the damping matrix, and the platform stiffness matrix, and obtain the frequency domain hydrodynamic coefficient and the motion response amplitude RAO of the platform model according to the mass matrix, the damping matrix, and the platform stiffness matrix; The third processing unit is used to input physical property parameters of the mooring and riser system into the platform model, establish the platform mooring system model, complete initialization, and obtain the initialized platform mooring system model; The fourth processing unit is used to input parameters in the platform model and solve the wave forces of various orders, mooring tension and riser force on the platform model under the initial time step by combining the initialized platform mooring system model, frequency domain hydrodynamic coefficients and motion response amplitude RAO; A fifth processing unit is used to solve the platform coupled motion equation of the platform model excluding the fluid force in the moon pool based on the various order wave forces, mooring tension and riser force in the fourth processing unit, and obtain the six-degree-of-freedom motion displacement of the platform model; The sixth processing unit is used to construct a viscous flow three-dimensional numerical water pool based on the computational fluid dynamics method, divide the computational domain grid, specify the overlapping grid area, define the finite volume method space discretization format, time discretization format, velocity-pressure coupling algorithm, define boundary conditions, and complete the initialization of the flow field; A seventh processing unit, for specifying the six-degree-of-freedom motion displacement of the platform model as the six-degree-of-freedom motion of the overlapping grid area; an eighth processing unit, for solving the nonlinear motion of the water body in the moon pool based on the sixth processing unit and the seventh processing unit, obtaining parameters including fluid pressure, and integrating the pressure on the inner wall of the moon pool to obtain the fluid force in the moon pool; The ninth processing unit is used to iterate the next time step, repeat the fourth processing unit, and add the fluid force in the moon pool calculated by the eighth processing unit to the time domain motion equation of the moon pool and platform coupling, solve the time domain motion equation of the moon pool and platform coupling, obtain the platform displacement, and iterate repeatedly until the last time calculation step is completed.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the hydrodynamic calculation method for coupling a moon pool with a platform as described in any one of claims 1 to 7 are implemented.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the hydrodynamic calculation method for coupling the moon pool and the platform as described in any one of claims 1 to 7 are implemented.

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