Response analysis method and device of semi-submersible ocean platform, electronic equipment and medium

Abstract

The invention discloses a response analysis method and device for a semi-submersible ocean platform, electronic equipment and a medium, and can be applied to the technical field of ocean structure engineering. According to the method, after the three-dimensional numerical pool is constructed and the semi-submersible type ocean platform model is constructed according to the actual size of the semi-submersible type ocean platform, the numerical pool calculation model of the semi-submersible type ocean platform is constructed according to the three-dimensional numerical pool and the semi-submersible type ocean platform model; then, a fluid domain in the numerical pool calculation model of the semi-submersible type ocean platform is updated in real time according to a dynamic grid algorithm, the real-time boundary position of the semi-submersible type ocean platform model is obtained, and the real-time mooring force of the semi-submersible type ocean platform is simulated according to the rigidity of the mooring cable and the real-time boundary position; therefore, the calculation precision and the calculation efficiency can be improved, then the dynamic response result of the semi-submersible type ocean platform is obtained through calculation according to the real-time mooring force, the real-time sea condition data and the numerical pool calculation model, and the dynamic response of the semi-submersible type ocean platform under various sea conditions is effectively analyzed.

Description

Technical Field

[0001] The present application relates to the technical field of marine structural engineering, and in particular to a response analysis method and device, electronic equipment and medium for a semi-submersible marine platform. Background Art

[0002] In the related art, semi-submersible offshore platforms will produce significant movement under the action of complex and harsh marine environmental loads, so analyzing the dynamic response of the platform is of great significance to the design and application of the platform. Due to the complexity of the structure and environmental load of the semi-submersible offshore platform, it is impossible to obtain the dynamic response of the semi-submersible offshore platform through theoretical analysis, and the model test method has the disadvantages of high cost, long cycle, and scale effect, making the numerical simulation method a widely used method. However, the numerical simulation method mostly uses commercial software such as AQWA and OrcaF l ex for numerical simulation. These software have low calculation accuracy and limited analysis of sea conditions when applied to semi-submersible offshore platforms. In addition, semi-submersible offshore platforms are mostly used for deep-sea oil and gas development, so that the mooring cable running through the entire sea depth is up to several thousand meters, resulting in a significant increase in the amount of calculation when the mooring cable model is added in the numerical simulation process, which reduces the calculation efficiency and further reduces the calculation accuracy.

[0003] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the invention

[0004] The main purpose of the embodiments of the present application is to propose a response analysis method and device, electronic equipment and medium for a semi-submersible marine platform, which can effectively improve the calculation accuracy and is suitable for analyzing various sea conditions.

[0005] To achieve the above object, one aspect of an embodiment of the present application provides a response analysis method for a semi-submersible offshore platform, the method comprising the following steps:

[0006] Construct a three-dimensional numerical water pool;

[0007] Constructing a semi-submersible offshore platform model according to the actual size of the semi-submersible offshore platform;

[0008] Constructing a numerical water tank calculation model of the semi-submersible offshore platform according to the three-dimensional numerical water tank and the semi-submersible offshore platform model;

[0009] The fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform is updated in real time according to a dynamic grid algorithm to obtain a real-time boundary position of the semi-submersible offshore platform model;

[0010] simulating a real-time mooring force of the semi-submersible offshore platform according to the stiffness of the mooring line and the real-time boundary position;

[0011] Acquiring real-time sea condition data of the sea area corresponding to the semi-submersible offshore platform;

[0012] The dynamic response result of the semi-submersible offshore platform is calculated based on the real-time mooring force, the real-time sea condition data and the numerical water tank calculation model.

[0013] In some embodiments, constructing a three-dimensional numerical water pool includes:

[0014] Constructing the three-dimensional numerical water pool according to the fluid volume model, turbulence model, velocity boundary wave making method and damping wave elimination method;

[0015] Among them, the fluid volume model is used to simulate the interface; the turbulence model is used to simulate turbulence; the velocity boundary wave generation method is used to generate waves; and the damping wave elimination method is used to eliminate waves.

[0016] In some embodiments, the time-averaged continuity equation of the three-dimensional numerical water pool is as follows:

[0017]

[0018] The momentum equation of the three-dimensional numerical water pool is as follows:

[0019]

[0020] Among them, u i and u j The fluid at x i 、x j The velocity component in the direction; ρ is the fluid density; p is the pressure; t is the time; μ is the molecular viscosity coefficient of the fluid; is the Reynolds stress; f i For x i Volume force in direction.

[0021] In some embodiments, the fluid volume model determines the interface through a volume fraction function; when the interface includes two phases, gas and liquid, the volume fraction function satisfies the following formula:

[0022]

[0023] Among them, a q is the volume fraction function of the qth phase fluid, q = 1, 2; V is the fluid velocity vector; t is time; is the divergence operator.

[0024] In some embodiments, the real-time updating of the fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform according to the moving grid algorithm to obtain the real-time boundary position of the semi-submersible offshore platform model includes:

[0025] Meshing the fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform;

[0026] The divided grids are updated according to the real-time position of the semi-submersible offshore platform.

[0027] In some embodiments, the meshing of the fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform includes:

[0028] Hexahedral grids are used to mesh the fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform.

[0029] In some embodiments, simulating the real-time mooring force of the semi-submersible offshore platform according to the stiffness of the mooring line and the real-time boundary position includes:

[0030] calculating the stiffness of the mooring line based on material properties of the mooring line;

[0031] Performing boundary surface and intra-surface node loop detection on the semi-submersible offshore platform model according to the stiffness of the mooring cable and the real-time boundary position to obtain four corner positions of the semi-submersible offshore platform model;

[0032] The real-time mooring force of the semi-submersible offshore platform is loaded at the four corner positions.

[0033] To achieve the above-mentioned purpose, another aspect of the embodiment of the present application provides a response analysis device for a semi-submersible marine platform, the device comprising:

[0034] The first module is used to construct a three-dimensional numerical water pool;

[0035] The second module is used to construct a semi-submersible offshore platform model according to the actual size of the semi-submersible offshore platform;

[0036] A third module is used to construct a numerical water tank calculation model of the semi-submersible offshore platform according to the three-dimensional numerical water tank and the semi-submersible offshore platform model;

[0037] The fourth module is used to update the fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform in real time according to the dynamic grid algorithm to obtain the real-time boundary position of the semi-submersible offshore platform model;

[0038] A fifth module, for simulating a real-time mooring force of the semi-submersible offshore platform according to the stiffness of the mooring cable and the real-time boundary position;

[0039] The sixth module is used to obtain real-time sea condition data of the sea area corresponding to the semi-submersible offshore platform;

[0040] The seventh module is used to calculate the dynamic response result of the semi-submersible offshore platform according to the real-time mooring force, the real-time sea condition data and the numerical water tank calculation model.

[0041] To achieve the above object, another aspect of an embodiment of the present application provides an electronic device, including:

[0042] at least one processor;

[0043] at least one memory for storing at least one program;

[0044] When the at least one program is executed by the at least one processor, the at least one processor implements the above method.

[0045] To achieve the above objective, another aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program implements the above method when executed by a processor.

[0046] The embodiments of the present application include at least the following beneficial effects: The present application provides a response analysis method and device, electronic equipment and medium for a semi-submersible marine platform. The scheme constructs a three-dimensional numerical water pool and a semi-submersible marine platform model according to the actual size of the semi-submersible marine platform, and then constructs a numerical water pool calculation model of the semi-submersible marine platform according to the three-dimensional numerical water pool and the semi-submersible marine platform model. Then, the fluid domain in the numerical water pool calculation model of the semi-submersible marine platform is updated in real time according to the dynamic grid algorithm to obtain the real-time boundary position of the semi-submersible marine platform model, and the real-time mooring force of the semi-submersible marine platform is simulated according to the stiffness of the mooring cable and the real-time boundary position, thereby improving the calculation accuracy and calculation efficiency. Then, after obtaining the real-time sea condition data of the sea area corresponding to the semi-submersible marine platform, the dynamic response result of the semi-submersible marine platform is calculated according to the real-time mooring force, the real-time sea condition data and the numerical water pool calculation model, thereby effectively analyzing the dynamic response of the semi-submersible marine platform corresponding to various sea conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a flow chart of a response analysis method for a semi-submersible offshore platform provided in an embodiment of the present application;

[0048] Figure 2 is an application flow chart of the response analysis method of a semi-submersible offshore platform provided in an embodiment of the present application;

[0049] Figure 3 It is a schematic diagram of a semi-submersible marine platform model provided in an embodiment of the present application;

[0050] Figure 4It is a schematic diagram of a three-dimensional numerical water tank calculation model of a semi-submersible platform provided in an embodiment of the present application;

[0051] Figure 5 is a flow chart for realizing the mooring effect based on the dynamic grid algorithm provided in an embodiment of the present application;

[0052] Figure 6 It is a schematic diagram of the grid division of the fluid domain in the downstream direction provided in the embodiment of the present application;

[0053] Figure 7 It is a schematic diagram of the cross-flow grid division of the fluid domain provided in the embodiment of the present application;

[0054] Figure 8 It is a response diagram of the semi-submersible offshore platform provided in the embodiment of the present application under the turbulent sea condition that occurs once a year;

[0055] Fig. 9 is a response diagram of a semi-submersible offshore platform provided in an embodiment of the present application under a turbulent sea condition that occurs once in ten years;

[0056] Fig.10 This is a response diagram of a semi-submersible offshore platform provided in an embodiment of the present application under a 100-year surge sea condition;

[0057] Fig.11 is a response diagram of a semi-submersible offshore platform provided in an embodiment of the present application under a heaving sea condition that occurs once a year;

[0058] Fig.12 is a response diagram of a semi-submersible offshore platform provided in an embodiment of the present application under a heaving sea condition that occurs once in ten years;

[0059] Fig.13 This is a response diagram of a semi-submersible offshore platform provided in an embodiment of the present application under a heaving sea condition that occurs once in a hundred years;

[0060] Fig.14 is a response diagram of a semi-submersible offshore platform provided in an embodiment of the present application under a once-a-year heave sea condition;

[0061] Fig.15 is a response diagram of a semi-submersible offshore platform provided in an embodiment of the present application under a heaving sea condition that occurs once in ten years;

[0062] Fig.16 This is a response diagram of a semi-submersible offshore platform provided in an embodiment of the present application under a once-in-a-century heave sea condition;

[0063] Fig.17 It is a structural schematic diagram of a response analysis device for a semi-submersible marine platform provided in an embodiment of the present application;

[0064] Fig.18It is a schematic diagram of the hardware structure of the electronic device provided in the embodiment of the present application. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application, they are only examples of devices and methods consistent with some aspects of the embodiments of the present application.

[0066] Before describing the embodiments of the present application in detail, some nouns and terms involved in the embodiments of the present application are first described. The nouns and terms involved in the embodiments of the present application are subject to the following explanations.

[0067] Computational Fluid Dynamics (CFD) is a branch of fluid mechanics. CFD is the product of the combination of modern fluid mechanics, numerical mathematics and computer science. It is an interdisciplinary science with strong vitality. It uses electronic computers as tools and applies various discrete mathematical methods to conduct numerical experiments, computer simulations and analytical research on various problems in fluid mechanics to solve various practical problems.

[0068] UDF (User Defined Function) is a user-defined function that allows users to add specific functions or modify default behaviors by programming when using Fluent for computational simulation. It is mainly written in C language and allows users to adjust or modify variables in the fluid domain in each simulation iteration to meet specific computational requirements.

[0069] In the related art, the existing numerical water pool analysis method has the following problems:

[0070] (1) Existing mature commercial software such as AQWA and OrcaF l ex do not consider the fluid viscosity effect, but the viscosity effect plays an important role in the interaction between waves and structures, affecting wave propagation and the stress of structures. In addition, it is difficult to consider the interaction between loads and structures, and between structures; the simulated sea conditions cannot be defined by users, etc., resulting in low calculation accuracy and limited analysis conditions.

[0071] (2) Since semi-submersible offshore platforms are mostly used for deep-sea oil and gas development, the mooring cables that run through the entire sea depth are several thousand meters long. If a mooring cable model is added to the numerical water pool, the water pool scale will be very large. In addition, in order to more accurately reflect the constraint effect of the mooring cable, the grid around the mooring cable needs to be encrypted, which will undoubtedly consume a lot of computing resources and reduce computing efficiency. At the same time, it will also reduce the calculation accuracy of the offshore platform part.

[0072] In view of this, the embodiments of the present application provide a response analysis method and device, electronic equipment and medium for a semi-submersible offshore platform. The present application constructs a three-dimensional numerical water pool that takes into account complex marine environmental loads, updates the dynamic grid area of ​​the semi-submersible offshore platform position in real time to simulate the movement of the platform under wind, wave and current loads, and calculates the mooring force in real time to simulate the platform constraints to realize the function of the platform mooring system. On this basis, the dynamic response of the platform under different sea conditions is analyzed, thereby effectively improving the calculation accuracy and analyzing the dynamic response of the semi-submersible offshore platform under various sea conditions.

[0073] The response analysis method of the semi-submersible marine platform provided in the embodiment of the present application relates to the field of marine structural engineering technology. The response analysis method of the semi-submersible marine platform provided in the embodiment of the present application can be applied to a terminal, can also be applied to a server, and can also be software running in a terminal or a server. In some embodiments, the terminal can be a smart phone, a tablet computer, a laptop computer, a desktop computer, a smart speaker, a smart watch, and a car terminal, etc., but is not limited to this; the server side can be configured as an independent physical server, or a server cluster or distributed system composed of multiple physical servers, and can also be configured as a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network; the software can be an application that implements the response analysis method of a semi-submersible marine platform, etc., but is not limited to the above forms.

[0074] The present application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, etc. The present application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present application can also be practiced in distributed computing environments, in which tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0075] Figure 1 is an optional flow chart of the response analysis method of the semi-submersible offshore platform provided in the embodiment of the present application. Figure 1 The method may include but is not limited to steps S110 to S170:

[0076] Step S110, constructing a three-dimensional numerical water pool;

[0077] Step S120: constructing a semi-submersible offshore platform model according to the actual size of the semi-submersible offshore platform;

[0078] Step S130, constructing a numerical water pool calculation model of the semi-submersible offshore platform according to the three-dimensional numerical water pool and the semi-submersible offshore platform model;

[0079] Step S140: updating the fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform in real time according to the dynamic grid algorithm to obtain the real-time boundary position of the semi-submersible offshore platform model;

[0080] Step S150, simulating the real-time mooring force of the semi-submersible offshore platform according to the stiffness of the mooring cable and the real-time boundary position;

[0081] Step S160, obtaining real-time sea condition data of the sea area corresponding to the semi-submersible offshore platform;

[0082] Step S170: Calculate the dynamic response result of the semi-submersible offshore platform according to the real-time mooring force, the real-time sea condition data and the numerical water tank calculation model.

[0083] In the embodiments of the present application, Figure 2As shown, the flow of the three-dimensional numerical water pool includes two-phase flow of water and air, and both water and air are assumed to be incompressible, three-dimensional viscous fluids. Therefore, the three-dimensional numerical water pool is established with the Navier-Stokes equation as the control equation. It can be understood that this embodiment constructs a three-dimensional numerical water pool according to the volume of fluid (VOF) model, turbulence model, velocity boundary wave making method and damping wave elimination method. Among them, the fluid volume model is used to simulate the interface; the turbulence model is used to simulate turbulence; the velocity boundary wave making method is used to make waves; and the damping wave elimination method is used to eliminate waves.

[0084] In the embodiment of the present application, the time-averaged continuity equation of the three-dimensional numerical water pool is as follows:

[0085]

[0086] The momentum equation of the three-dimensional numerical pool is as follows:

[0087]

[0088] Among them, u i and u j The fluid at x i 、x j The velocity component in the direction; ρ is the fluid density; p is the pressure; t is the time; μ is the molecular viscosity coefficient of the fluid; is the Reynolds stress; f i For x i Volume force in direction.

[0089] The fluid volume model determines the interface through a volume fraction function; when the interface includes two phases, gas and liquid, the volume fraction function satisfies the following formula:

[0090]

[0091] Among them, a q is the volume fraction function of the qth phase fluid, q = 1, 2; v is the fluid velocity vector; t is time; is the divergence operator.

[0092] Turbulence models can be selected as needed, such as RNGk-ε turbulence model, Realizab le k-ε turbulence model, SST k-ω turbulence model, etc. The velocity boundary wave making method and damping wave elimination method are used to realize wave making and wave elimination in the numerical water pool. Wave making can customize various wave models, such as high-precision fifth-order Stokes wave, etc.

[0093] In the embodiment of the present application, the following is constructed according to the actual size of the semi-submersible offshore platform: Figure 3When the semi-submersible offshore platform model is shown, a finite element model can be established according to the actual size of the semi-submersible offshore platform as the semi-submersible offshore platform model, and the calculation domain and boundary conditions of the three-dimensional numerical water pool are set. Figure 4 The three-dimensional numerical water tank calculation model of the semi-submersible platform is shown in the figure. The boundary conditions are set as the left boundary as the velocity inlet, which can define the wind wave and current load, and the right boundary as the pressure outlet; the two sides and the top are symmetric boundaries; the bottom is a no-slip wall boundary; and the surface of the semi-submersible offshore platform is a dynamic mesh wall.

[0094] In the embodiment of the present application, the process of real-time updating of the fluid domain in the numerical water pool calculation model of the semi-submersible marine platform according to the dynamic mesh algorithm can be carried out by meshing the fluid domain in the numerical water pool calculation model of the semi-submersible marine platform, and then updating the divided mesh according to the real-time position of the semi-submersible marine platform. It can be understood that the meshing of the fluid domain is divided by hexahedral meshes, the middle marine platform area is encrypted and the boundary layer is set, and the mesh of the middle fluid domain gradually becomes sparse outward; the boundary layer is divided in the near-wall area of ​​the platform, and the mesh of the fluid domain outside the boundary layer reaches the maximum value of the mesh at a fixed growth rate. The dynamic mesh implementation of the platform motion is to first determine the equilibrium position of the platform under the action of gravity and buoyancy under the conditions of initializing wind, wave, flow and gravity load; then in each time step, solve the fluid control equation transmitted by the wind, wave and flow load, obtain the wind load and hydrodynamic action on the platform, and transmit it to the platform coupling wall; then obtain the displacement response in each direction by solving the platform motion equation, and update the boundary position of the marine platform; finally, recalculate the flow field area and update the new mesh.

[0095] In the embodiment of the present application, the mooring system effect is realized by converting it into a mooring force and applying it to the corresponding position of the platform. It can be understood that in the process of simulating the real-time mooring force of the semi-submersible marine platform according to the stiffness of the mooring cable and the real-time boundary position, the stiffness of the mooring cable can be calculated according to the material properties of the mooring cable, and then the boundary surface and the nodes within the surface of the semi-submersible marine platform model are cyclically detected according to the stiffness of the mooring cable and the real-time boundary position to obtain the four corner positions of the semi-submersible marine platform model, and the real-time mooring force of the semi-submersible marine platform is loaded at the four corner positions. Specifically, the cyclic detection process can be detected through the UDF (User Defined Function) internal function in Fluent. When the real-time mooring force of the semi-submersible marine platform is loaded at the four corner positions, the mooring force will also be updated in real time with the platform position. In this embodiment, the mooring effect implementation process based on the dynamic grid algorithm is as follows. Figure 5As shown. It can be understood that the update of the boundary mesh uses the spring approximate smoothing algorithm and the local reconstruction algorithm to stretch or compress the mesh or reconstruct the local small mesh that does not meet the calculation requirements, thereby generating a boundary mesh of qualified quality.

[0096] In an embodiment of the present application, after obtaining the three-dimensional data pool calculation model, real-time sea condition data of parameters such as wave height and period, wind speed and current velocity in the sea area corresponding to the semi-submersible offshore platform are obtained, and the real-time sea condition data is used as the entrance of the three-dimensional data pool calculation model. The PI SO (Pressure-Implicate with Splitting of Operators) algorithm is used to process the pressure-velocity coupling problem, and the vertical swing, longitudinal swing and lateral swing responses of the platform under the sea conditions are calculated.

[0097] It can be seen that the embodiment of the present application is based on the Navier-Stokes equation considering the movement of viscous fluid, adopts the VOF model to capture the water-liquid interface of the numerical water pool, selects a suitable turbulence model, and adopts the velocity boundary wave making method and the damping wave breaking method to realize the wave making and wave breaking of the numerical water pool to establish a three-dimensional numerical water pool; then the dynamic grid technology is used to realize the movement of floating structures such as semi-submersible marine platforms under the action of wind, waves and currents, and in order to improve the calculation accuracy and efficiency, real-time calculation and updating of the mooring force position are adopted to realize the action of the mooring system; finally, the response of the platform is calculated according to the actual sea conditions of the platform, so that the embodiment of the present application can easily obtain the load conditions of different sea conditions through customization, arbitrarily use the wave theory with higher accuracy to simulate ocean waves, and can well reflect the turbulent effect in the flow field, so that the numerical water pool method of the embodiment of the present application is more widely applicable, and provides a reliable tool for studying the dynamic response of semi-submersible platforms serving in complex marine environments.

[0098] In some embodiments, a classic double-floating four-column semi-submersible offshore platform is used as an example to establish a numerical tank model of the platform. The semi-submersible offshore platform includes two lower buoys, four columns, two struts and an upper deck. The platform model is as follows: Figure 3 Four tensioned mooring cables are arranged at the four bottom corners of the outer side of the platform's floating body. The platform and mooring cable parameters are shown in Table 1, where the mooring cable type is anchor chain.

[0099] Table 1

[0100]

[0101]

[0102] Then, the Navier-Stokes equation is used as the control equation to establish a three-dimensional numerical water pool, and the fluid domain size is determined to be 1600m×500m×240m, the inlet is 460m away from the bow of the platform, the water depth is 116m, and the wave-breaking area is twice the wavelength. The boundary conditions are set as follows: the left boundary is the velocity inlet, which can define the wind, wave and current loads, and the right boundary is the pressure outlet; the two sides and the top are symmetrical boundaries; the bottom is a no-slip wall boundary; the surface of the ocean platform is a dynamic mesh wall. Among them, the schematic diagram of the three-dimensional numerical water pool calculation model is as follows Figure 4 shown.

[0103] Then, the fluid domain grid is divided by hexahedral grid. The middle offshore platform area is encrypted and the boundary layer is set. The grid of the middle fluid domain is gradually sparse from the outside. The boundary layer is divided in the near-wall area of ​​the platform. The height of the first layer of grid is 0.05m, and 10 layers of boundary layers are divided at a growth rate of 1.2. The maximum value of the grid of the fluid domain outside the boundary layer is set to 20m, and the grid size gradually increases to the maximum value of the grid at a growth rate of 1.2. The divided fluid domain grid is as follows Figure 6 and Figure 7 shown.

[0104] Since the semi-submersible offshore platform moves significantly under the action of wind, waves and currents, the grid of this part needs to be updated in real time. Therefore, UDF compilation is used to implement dynamic grid technology. The DEFI NE_SODF_PROPERT I ES function is compiled for the semi-submersible offshore platform area to define the platform mass and its moment of inertia, and release the degrees of freedom in the three directions of x, y, and z. Under the conditions of initializing wind, wave, current and gravity loads, the equilibrium position of the platform under the action of gravity and buoyancy is first determined; then, in each time step, the fluid control equation transmitted by the wind, wave and current load is solved to obtain the wind load and hydrodynamic effect on the platform, and then transmitted to the platform coupling wall; then, the displacement response in each direction is obtained by solving the platform motion equation, and the boundary position of the offshore platform is updated; finally, the flow field is recalculated and a new grid is updated.

[0105] In order to balance the computational efficiency and computational accuracy, this embodiment uses UDF compilation to simulate the mooring system. First, the stiffness of the mooring cable is calculated according to the material properties of the mooring cable, and then the boundary surface and the node loop detection in the surface are performed through the internal function of UDF to obtain the center of gravity position and the four corner positions of the platform. The mooring force updated in real time is loaded at the four corner positions, and the mooring force is also updated in real time with the platform position. The boundary grid is updated by stretching, compressing the grid or reconstructing the local small grid that does not meet the calculation requirements through the spring approximate smoothing algorithm and the local reconstruction algorithm to generate a boundary grid of qualified quality.

[0106] Then the dynamic response of a semi-submersible offshore platform in a certain sea area under three sea conditions is analyzed. Figure 8-Figure 16 Among them, the sea state parameters are shown in Table 2:

[0107] Table 2

[0108]

[0109] from Figure 8 , Fig. 9 , Fig.10 , Fig.11 , Fig.12 , Fig.13 , Fig.14 , Fig.15 and Fig.16 It can be seen that the dynamic response of the platform in each sea condition is the largest in the longitudinal sway response in the downstream direction. Among them, the maximum longitudinal displacement is as high as 25.9997m in the sea condition of once in a hundred years. The reason is that the mooring system constraints of floating structures such as semi-submersible platforms are weak, which enables them to produce a larger motion amplitude in the safety restricted area. The heave displacement caused by the combined action of wave force and gravity and buoyancy is also quite significant. Among them, the maximum heave displacement is 3.4767m in the sea condition of once in a hundred years. The reason is that the semi-submersible platform serving in the deep sea has greater flexibility under mooring conditions, which makes its heave response amplitude larger. Due to the flow around the platform, a certain transverse displacement is also generated. Therefore, the numerical pool well reflects the influence of wind, wave and current loads on the platform movement.

[0110] Reference Fig.17 , the embodiment of the present application provides a response analysis device for a semi-submersible marine platform, the device comprising:

[0111] The first module 1710 is used to construct a three-dimensional numerical water pool;

[0112] The second module 1720 is used to construct a semi-submersible offshore platform model according to the actual size of the semi-submersible offshore platform;

[0113] The third module 1730 is used to construct a numerical water tank calculation model of the semi-submersible offshore platform according to the three-dimensional numerical water tank and the semi-submersible offshore platform model;

[0114] The fourth module 1740 is used to update the fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform in real time according to the dynamic grid algorithm to obtain the real-time boundary position of the semi-submersible offshore platform model;

[0115] A fifth module 1750 is used to simulate the real-time mooring force of the semi-submersible offshore platform based on the stiffness of the mooring line and the real-time boundary position;

[0116] The sixth module 1760 is used to obtain real-time sea condition data of the sea area corresponding to the semi-submersible offshore platform;

[0117] The seventh module 1770 is used to calculate the dynamic response results of the semi-submersible offshore platform based on the real-time mooring force, real-time sea condition data and the numerical water tank calculation model.

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

[0119] The embodiment of the present application also provides an electronic device, the electronic device includes a memory and a processor, the memory stores a computer program, and the processor implements the above-mentioned response analysis method of the semi-submersible marine platform when executing the computer program. The electronic device can be any intelligent terminal including a tablet computer, a car computer, etc.

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

[0121] See also Fig.18 , Fig.18 The hardware structure of an electronic device of another embodiment is illustrated, and the electronic device includes:

[0122] The processor 1810 may be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present application.

[0123] The memory 1820 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 1820 can store an operating system and other application programs. When the technical solution provided in the embodiment of this specification is implemented by software or firmware, the relevant program code is stored in the memory 1820, and the processor 1810 calls and executes the response analysis method of the semi-submersible marine platform in the embodiment of the present application;

[0124] Input / output interface 1830, used to implement information input and output;

[0125] Communication interface 1840, used to realize communication interaction between the device and other devices, which can be realized through wired mode (such as USB, network cable, etc.) or wireless mode (such as mobile network, WI FI, Bluetooth, etc.);

[0126] bus 1850 , which transmits information between the various components of the device (e.g., processor 1810 , memory 1820 , input / output interface 1830 , and communication interface 1840 );

[0127] The processor 1810 , the memory 1820 , the input / output interface 1830 , and the communication interface 1840 are communicatively connected to each other within the device via a bus 1850 .

[0128] An embodiment of the present application also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the response analysis method of the semi-submersible marine platform is implemented.

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

[0130] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0131] The embodiments described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0132] Those skilled in the art will appreciate that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0133] The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0134] Those skilled in the art will appreciate that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices may be implemented as software, firmware, hardware, or a suitable combination thereof.

[0135] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0136] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0137] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the above units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0138] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0139] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0140] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including multiple instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, referred to as ROM), random access memory (Random Access Memory, referred to as RAM), disk or optical disk and other media that can store programs.

[0141] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the present invention should be within the scope of the rights of the present invention.

Claims

1. A response analysis method for a semi-submersible offshore platform, characterized in that: The method comprises the following steps: Construct a three-dimensional numerical water pool; Constructing a semi-submersible offshore platform model according to the actual size of the semi-submersible offshore platform; Constructing a numerical water tank calculation model of the semi-submersible offshore platform according to the three-dimensional numerical water tank and the semi-submersible offshore platform model; The fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform is updated in real time according to a dynamic grid algorithm to obtain a real-time boundary position of the semi-submersible offshore platform model; simulating a real-time mooring force of the semi-submersible offshore platform according to the stiffness of the mooring line and the real-time boundary position; Acquiring real-time sea condition data of the sea area corresponding to the semi-submersible offshore platform; The dynamic response result of the semi-submersible offshore platform is calculated based on the real-time mooring force, the real-time sea condition data and the numerical water tank calculation model.

2. The method according to claim 1, characterized in that The constructing of a three-dimensional numerical water pool comprises: Constructing the three-dimensional numerical water pool according to the fluid volume model, turbulence model, velocity boundary wave making method and damping wave elimination method; Among them, the fluid volume model is used to simulate the interface; the turbulence model is used to simulate turbulence; the velocity boundary wave generation method is used to generate waves; and the damping wave elimination method is used to eliminate waves.

3. The method according to claim 2, characterized in that The time-averaged continuity equation of the three-dimensional numerical water pool is as follows: The momentum equation of the three-dimensional numerical water pool is as follows: Among them, u i and u j The fluid at x i 、x j The velocity component in the direction; ρ is the fluid density; p is the pressure; t is the time; μ is the molecular viscosity coefficient of the fluid; is the Reynolds stress; f i For x i Volume force in direction.

4. The method according to claim 2, characterized in that: The fluid volume model determines the interface through a volume fraction function; when the interface includes two phases, gas and liquid, the volume fraction function satisfies the following formula: Among them, a q is the volume fraction function of the qth phase fluid, q = 1, 2; V is the fluid velocity vector; t is time; is the divergence operator.

5. The method according to claim 1, characterized in that: The method of updating the fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform in real time according to the dynamic grid algorithm to obtain the real-time boundary position of the semi-submersible offshore platform model includes: Meshing the fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform; The divided grids are updated according to the real-time position of the semi-submersible offshore platform.

6. The method according to claim 5, characterized in that The gridding of the fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform includes: Hexahedral grids are used to mesh the fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform.

7. The method according to claim 1, characterized in that The simulating the real-time mooring force of the semi-submersible offshore platform according to the stiffness of the mooring cable and the real-time boundary position comprises: calculating the stiffness of the mooring line based on material properties of the mooring line; Performing boundary surface and intra-surface node loop detection on the semi-submersible offshore platform model according to the stiffness of the mooring cable and the real-time boundary position to obtain four corner positions of the semi-submersible offshore platform model; The real-time mooring force of the semi-submersible offshore platform is loaded at the four corner positions.

8. A response analysis device for a semi-submersible offshore platform, characterized in that: The device comprises: The first module is used to construct a three-dimensional numerical water pool; The second module is used to construct a semi-submersible offshore platform model according to the actual size of the semi-submersible offshore platform; A third module is used to construct a numerical water tank calculation model of the semi-submersible offshore platform according to the three-dimensional numerical water tank and the semi-submersible offshore platform model; The fourth module is used to update the fluid domain in the numerical water tank calculation model of the semi-submersible offshore platform in real time according to the dynamic grid algorithm to obtain the real-time boundary position of the semi-submersible offshore platform model; A fifth module, for simulating a real-time mooring force of the semi-submersible offshore platform according to the stiffness of the mooring cable and the real-time boundary position; The sixth module is used to obtain real-time sea condition data of the sea area corresponding to the semi-submersible offshore platform; The seventh module is used to calculate the dynamic response result of the semi-submersible offshore platform according to the real-time mooring force, the real-time sea condition data and the numerical water tank calculation model.

9. An electronic device, characterized in that: include: at least one processor; at least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the method according to any one of claims 1 to 7.

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

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