A time-domain simulation method and related device for wave energy float model

Abstract

This application discloses a time-domain simulation method for a wave energy float model and related devices. The method includes: decomposing the wave energy float model to obtain a gravity field model, a wave energy float system model, a wave force calculation model, a buoyancy calculation model, an added mass calculation model, a damping force calculation model, a hydrostatic restoring force calculation model, and a viscous force calculation model; modeling each decomposed sub-model using OpenModelica and establishing a connection relationship between each sub-model, and solving the model using a solver. This application decomposes the wave energy float model into multiple sub-models according to potential flow theory for modeling. After physically connecting the sub-models, equations can be established. The equations are solved using a solver, greatly reducing the steps in the physical modeling process and the difficulty of solving the equations, thereby improving the reusability, reconfigurability, and scalability of the time-domain simulation method for the wave energy float model.

Description

Technical Field

[0001] The present application relates to the technical field of wave energy float model simulation, and in particular to a time domain simulation method and related devices for a wave energy float model. Background Art

[0002] Wave energy is a renewable energy source with a wide distribution range and high energy density. Wave power generation technology converts the kinetic energy of waves into electricity, making it a clean and environmentally friendly method of generating electricity. Before a wave energy device is put into operation, simulation is required to evaluate its performance and optimize the design of its wave energy float.

[0003] At present, when performing time-domain simulation of wave energy float models, most existing technologies adopt the idea of procedural modeling (causal modeling), using languages such as Fortran and C to model and solve wave energy float models. Although this meets the actual needs of engineering, for engineers, it is not only necessary to master the mathematical derivation and process decomposition of the wave energy float model, but also to clarify the solution sequence, system decoupling and solution processes, which greatly increases the workload; and the existing simulation methods have poor reusability, reconfigurability and scalability. Summary of the Invention

[0004] The present application provides a time-domain simulation method and related devices for a wave energy float model, which are used to improve the technical problems existing in the prior art, such as the complex modeling process, poor reusability, reconfigurability and scalability.

[0005] In view of this, the first aspect of the present application provides a time-domain simulation method for a wave energy buoy model, comprising:

[0006] The wave energy float model is decomposed to obtain the gravity field model, wave energy float system model, wave force calculation model, buoyancy calculation model, added mass calculation model, damping force calculation model, hydrostatic restoring force calculation model, and viscous force calculation model;

[0007] Use OpenModelica to model the decomposed sub-models and establish connections between them. Use the solver to solve the model, including:

[0008] Modeling the gravity field model using OpenModelica to determine the gravity field where each sub-model is located;

[0009] The truss structure connecting the wave energy float was modeled using OpenModelica. The spring stiffness and damper damping were set. The displacement, velocity, acceleration, angular displacement, angular velocity, and angular acceleration of the float were calculated by setting the relevant parameters of the float. The wave energy float system model was then connected to the remaining sub-models.

[0010] Modeling the buoyancy calculation model using OpenModelica to obtain buoyancy, and transferring the buoyancy to the wave energy float system model;

[0011] Modeling the viscous force calculation model using OpenModelica, calculating the viscous force according to the velocity and angular velocity of the float transmitted by the wave energy float system model, and transmitting the viscous force to the wave energy float system model;

[0012] Modeling the wave force calculation model using OpenModelica, calculating the wave force based on the initial angle and displacement of the float transmitted by the wave energy float system model, and transmitting the wave force to the wave energy float system model;

[0013] Modeling the damping force calculation model using OpenModelica to obtain the damping force, and transmitting the damping force to the wave energy buoy system model;

[0014] Modeling the added mass calculation model using OpenModelica, calculating the added mass force according to the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and transmitting the added mass force to the wave energy float system model;

[0015] Modeling the hydrostatic restoring force calculation model using OpenModelica, calculating the hydrostatic restoring force based on the displacement and angular displacement of the float transmitted by the wave energy float system model, and transmitting the hydrostatic restoring force to the wave energy float system model;

[0016] Set the simulation duration and time step, and use the solver to solve the constructed model.

[0017] Optionally, modeling the viscous force calculation model using OpenModelica, calculating the viscous force according to the velocity and angular velocity of the float transmitted by the wave energy float system model, and transmitting the viscous force to the wave energy float system model includes:

[0018] The RealInput module in OpenModelica receives the velocity and angular velocity of the float transmitted by the wave energy float system model, and the Gain module in OpenModelica sets the damping value;

[0019] Connect the RealInput module to the Gain module to output the viscous force obtained by multiplying the velocity, angular velocity and damping value;

[0020] The Gain module is connected to the ForceAndTorque module in OpenModelica to convert the viscous force into force and torque, and the force and torque converted from the viscous force are transmitted to the wave energy float system model through Frame_b in OpenModelica.

[0021] Optionally, modeling the wave force calculation model using OpenModelica, calculating the wave force according to the initial angle and displacement of the float transmitted by the wave energy float system model, and transmitting the wave force to the wave energy float system model includes:

[0022] Receive the initial angle and displacement of the float from the wave energy float system model through the RealInput module in OpenModelica;

[0023] A wave force calculation model is constructed in OpenModelica, and the initial angle and displacement of the float are substituted into the wave force calculation model to calculate the wave force;

[0024] The wave force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque obtained by the wave force conversion are transmitted to the wave energy buoy system model through Frame_b in OpenModelica.

[0025] Optionally, modeling the damping force calculation model using OpenModelica to obtain the damping force, and transmitting the damping force to the wave energy buoy system model includes:

[0026] receiving the velocity and angular velocity of the float transmitted by the wave energy float system model through the RealInput module in OpenModelica;

[0027] A damping force calculation model is constructed in OpenModelica, and the velocity and angular velocity of the float are substituted into the damping force calculation model to calculate the damping force;

[0028] The damping force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque converted from the damping force are transmitted to the wave energy buoy system model through Frame_b in OpenModelica.

[0029] Optionally, modeling the damping force calculation model using OpenModelica to obtain the damping force, and transmitting the damping force to the wave energy buoy system model includes:

[0030] A frequency domain delay function is constructed using the additional mass coefficient and the potential flow damping coefficient obtained by the potential flow frequency domain calculation software, and the frequency domain delay function is identified by the frequency domain regression method to obtain a fitted transfer function;

[0031] Converting the transfer function into a state-space representation to obtain state-space coefficients;

[0032] Constructing a state-space model in OpenModelica, and substituting the state-space coefficients into the state-space model to calculate the damping force;

[0033] The damping force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque converted from the damping force are transmitted to the wave energy buoy system model through Frame_b in OpenModelica.

[0034] Optionally, modeling the added mass calculation model using OpenModelica, calculating the added mass force according to the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and transmitting the added mass force to the wave energy float system model includes:

[0035] receiving the acceleration and angular acceleration of the float transmitted by the wave energy float system model through the RealInput module in OpenModelica;

[0036] Set the added mass value through the Gain block in OpenModelica, connect the RealInput block to the Gain block, and output the added mass force obtained by multiplying the acceleration and angular acceleration by the added mass.

[0037] The added mass force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque obtained by the added mass force conversion are transmitted to the wave energy buoy system model through Frame_b in OpenModelica.

[0038] Optionally, the hydrostatic restoring force calculation model is modeled using OpenModelica, the hydrostatic restoring force is calculated according to the displacement and angular displacement of the float transmitted by the wave energy float system model, and the hydrostatic restoring force is transmitted to the wave energy float system model, including:

[0039] receiving the displacement and angular displacement of the float transmitted by the wave energy float system model through the RealInput module in OpenModelica;

[0040] Set the linear statics restoring stiffness value through the Gain module in OpenModelica;

[0041] Connect the RealInput module to the Gain module to output the hydrostatic restoring force obtained by multiplying the displacement and angular displacement by the linear static restoring stiffness value;

[0042] The hydrostatic restoring force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque converted from the hydrostatic restoring force are transmitted to the wave energy buoy system model through Frame_b in OpenModelica.

[0043] A second aspect of the present application provides a time-domain simulation device for a wave energy buoy model, comprising:

[0044] A decomposition unit is used to decompose the wave energy float model to obtain a gravity field model, a wave energy float system model, a wave force calculation model, a buoyancy calculation model, an added mass calculation model, a damping force calculation model, a hydrostatic restoring force calculation model, and a viscous force calculation model;

[0045] The simulation unit is used to model the decomposed sub-models using OpenModelica, establish connections between the sub-models, and solve the model using the solver.

[0046] The simulation unit is specifically used for:

[0047] Modeling the gravity field model using OpenModelica to determine the gravity field where each sub-model is located;

[0048] The truss structure connecting the wave energy float was modeled using OpenModelica. The spring stiffness and damper damping were set. The displacement, velocity, acceleration, angular displacement, angular velocity, and angular acceleration of the float were calculated by setting the relevant parameters of the float. The wave energy float system model was then connected to the remaining sub-models.

[0049] Modeling the buoyancy calculation model using OpenModelica to obtain buoyancy, and transferring the buoyancy to the wave energy float system model;

[0050] Modeling the viscous force calculation model using OpenModelica, calculating the viscous force according to the velocity and angular velocity of the float transmitted by the wave energy float system model, and transmitting the viscous force to the wave energy float system model;

[0051] Modeling the wave force calculation model using OpenModelica, calculating the wave force based on the initial angle and displacement of the float transmitted by the wave energy float system model, and transmitting the wave force to the wave energy float system model;

[0052] Modeling the damping force calculation model using OpenModelica to obtain the damping force, and transmitting the damping force to the wave energy buoy system model;

[0053] Modeling the added mass calculation model using OpenModelica, calculating the added mass force according to the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and transmitting the added mass force to the wave energy float system model;

[0054] Modeling the hydrostatic restoring force calculation model using OpenModelica, calculating the hydrostatic restoring force based on the displacement and angular displacement of the float transmitted by the wave energy float system model, and transmitting the hydrostatic restoring force to the wave energy float system model;

[0055] Set the simulation duration and time step, and use the solver to solve the constructed model.

[0056] A third aspect of the present application provides an electronic device, the device comprising a processor and a memory;

[0057] The memory is used to store program code and transmit the program code to the processor;

[0058] The processor is configured to execute the time-domain simulation method for a wave energy buoy model according to any one of the first aspects according to the instructions in the program code.

[0059] In a fourth aspect, the present application provides a computer-readable storage medium for storing program code. When the program code is executed by a processor, the time-domain simulation method for a wave energy buoy model according to any one of the first aspects is implemented.

[0060] It can be seen from the above technical solutions that this application has the following advantages:

[0061] The time-domain simulation method for a wave energy float model provided in this application utilizes OpenModelica to decompose the wave energy float model into multiple sub-models according to potential flow theory for modeling. The physical relationships between the sub-models are then connected to establish equations. By selecting the simulation duration and time step, the solver automatically discretizes time and solves the system of equations, significantly reducing the number of steps in the physical modeling process and the difficulty of solving the system of equations, thereby reducing the complexity of the modeling process. This application abstracts each sub-model into a class for separate modeling, and then connects the abstracted classes to solve the problem of the entire system. After the connection, equations are established, and the solver automatically discretizes time and solves the system of equations, which increases the scalability of the wave energy float model. The OpenModelica simulation platform used provides graphical custom models corresponding to the classes. The reuse of graphical models greatly reduces the difficulty of reuse and reconstruction, thereby improving the reusability, reconfigurability, and scalability of the time-domain simulation method for the wave energy float model. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0063] Figure 1 A schematic flow chart of a time-domain simulation method for a wave energy buoy model provided in an embodiment of the present application;

[0064] Figure 2 A schematic diagram of the connection relationship between the sub-models provided in the embodiment of the present application;

[0065] Figure 3 A flow chart for solving the state space coefficients provided in an embodiment of the present application;

[0066] Figure 4 A structural schematic diagram of a time-domain simulation device for a wave energy float model provided in an embodiment of the present application. DETAILED DESCRIPTION

[0067] In order to help those skilled in the art better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 those skilled in the art without creative work are within the scope of protection of this application.

[0068] For easier understanding, please refer to Figure 1 The embodiment of the present application provides a time-domain simulation method for a wave energy buoy model, comprising:

[0069] Step 110: Decompose the wave energy float model to obtain a gravity field model, a wave energy float system model, a wave force calculation model, a buoyancy calculation model, an added mass calculation model, a damping force calculation model, a hydrostatic restoring force calculation model, and a viscous force calculation model.

[0070] The wave energy buoy model is a coupled solution model, which is decomposed into 8 sub-models, namely gravity field model, wave energy buoy system model, wave force calculation model, buoyancy calculation model, added mass calculation model, damping force calculation model, hydrostatic restoring force calculation model, and viscous force calculation model.

[0071] Step 120: Model each sub-model obtained by the decomposition using OpenModelica and establish a connection relationship between each sub-model, and solve the model using a solver.

[0072] The coupled solution model is the overall model, also known as the main function, where the various modules are called, data is transferred, and coupled calculations are performed. After modeling and connecting the decomposed submodels using OpenModelica, the simulation duration and time step are selected, and the solution is performed using a solver, such as the Runge-Kutta method.

[0073] The process of modeling the decomposed sub-models and establishing connections between them using OpenModelica and solving the model using the solver includes:

[0074] S1. Model the gravity field model using OpenModelica and determine the gravity field where each sub-model is located;

[0075] There is a gravity field in the physical world, which cannot be ignored during the simulation process. The embodiment of the present application uses the World module provided in OpenModelica to define the gravity field where the multi-body model is located.

[0076] S2. Model the truss structure connecting the wave energy float using OpenModelica, set the spring stiffness and damper damping, monitor the float's displacement, velocity, acceleration, angular displacement, angular velocity, and angular acceleration, and establish connections between the wave energy float system model and the remaining sub-models.

[0077] The wave energy float system model includes a truss model, a wave energy float, and a spring stiffness and damping model. The wave energy float can be modeled using the BodyShape module within OpenModelica. Target parameters such as the float's mass, center of gravity, and moment of inertia can be input, as well as initial displacement and initial angle. The sensor module within OpenModelica monitors the float's displacement, velocity, acceleration, angular displacement, angular velocity, and angular acceleration. These parameters are output using the RealOutput module as parameters for calculations in other submodels.

[0078] The truss model models the truss structure connecting the wave energy float. The truss structure in the embodiment of the present application is modeled using the FixedTranslation module provided in OpenModelica;

[0079] The spring stiffness damping model uses the SpringDamperSeries module in OpenModelica, which can set the spring stiffness and damper damping. The spring stiffness damping model is used as the energy harvesting equivalent module of the wave energy float to simulate the effect of the energy harvesting device on the wave energy float. The wave energy float system model is connected to the remaining sub-models, such as Figure 2 shown.

[0080] S3. Model the buoyancy calculation model using OpenModelica to obtain the buoyancy and transfer the buoyancy to the wave energy float system model.

[0081] The buoyancy calculation model uses a buoyancy simulation submodel. The buoyancy of the object is input into this submodel, which is calculated using Archimedes' principle. During the coupled calculation, this submodel applies the buoyancy to the object and transfers it to the wave energy float system model. The buoyancy value is input into the Constant block provided by OpenModelica, which is then connected to the WorldForce block provided by OpenModelica to convert the buoyancy into a force. This force is then output to the wave energy float system model using Frame_b in OpenModelica.

[0082] S4. Modeling a viscous force calculation model using OpenModelica, calculating the viscous force based on the velocity and angular velocity of the float transmitted by the wave energy float system model, and transmitting the viscous force to the wave energy float system model;

[0083] The viscous force calculation model is used to calculate the viscous force on an object. The viscosity of water is ignored in the basic assumptions of potential flow theory, but in actual physical phenomena, viscosity is equally important for underwater structures. This embodiment of the application uses viscosity correction to consider the viscous damping force in the floating structure. The viscous force F 黏 The calculation process is:

[0084]

[0085] Where, is the speed of the jth degree of freedom of the float; the value range of subscript j is 1~6; the six degrees of freedom of the float are 1 = surge, 2 = sway, 3 = heave, 4 = roll, 5 = pitch, 6 = bow; is the matrix of the float's velocity and angular velocity, It is a 6*1 matrix, and the elements in the matrix include the velocities in the three directions of surge, sway and heave, and the angular velocities in the three directions of roll, pitch and yaw; D 阻尼 is the corresponding viscous damping, which is a 6*6 matrix.

[0086] The RealInput module in OpenModelica receives the velocity and angular velocity transmitted by the wave energy float system model. The viscous damping value is input into the Gain module in OpenModelica. Connecting the RealInput module to the Gain module multiplies the velocity, angular velocity, and viscous damping to obtain the viscous force. Connecting the Gain module to the ForceAndTorque module in OpenModelica converts the viscous force into force and torque. Using Frame_b in OpenModelica, the force and torque are then output to the wave energy float system model.

[0087] S5. Model the wave force calculation model using OpenModelica, calculate the wave force based on the initial angle and displacement of the float transmitted by the wave energy float system model, and transmit the wave force to the wave energy float system model.

[0088] The RealInput module in OpenModelica receives the initial angle and displacement of the float from the wave energy float system model. The wave force calculation model is constructed in OpenModelica, and the initial angle and displacement of the float are substituted into the wave force calculation model to calculate the wave force F. wave , where the wave force calculation model includes the wave force function, namely:

[0089]

[0090] Where A represents the amplitude of the wave function, X jrepresents the response amplitude operator, t represents the preset time length, The calculated wave force can be converted into force and torque using the ForceAndTorque module in OpenModelica. The converted force and torque are then transferred to the wave energy float system model using Frame_b in OpenModelica.

[0091] S6. Model the damping force calculation model using OpenModelica to obtain the damping force, and transfer the damping force to the wave energy float system model;

[0092] In one embodiment, the damping force is calculated using a direct integration method in the damping force sub-model, specifically including:

[0093] The RealInput module in OpenModelica receives the velocity and angular velocity of the float transmitted by the wave energy float system model;

[0094] Construct a damping force calculation model in OpenModelica, and substitute the velocity and angular velocity of the float into the damping force calculation model to calculate the damping force ; Among them, the damping force calculation model is:

[0095]

[0096] Among them, Nw is the number of angular frequencies corresponding to the potential flow damping coefficient; Nt is the number of time series from time 0 to the current time, that is, , t is the current moment, dt is the step interval time; B(ω i ) is the potential flow damping coefficient corresponding to the angular frequency; is the angular frequency interval; is the jth moment, v j for The speed of the float reference point at that moment.

[0097] The damping force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque converted from the damping force are transmitted to the wave energy float system model through Frame_b in OpenModelica.

[0098] In another embodiment, the embodiment of the present application takes into account that the solution speed of calculating the damping force by using the direct integration method is slow. In order to improve the solution speed, the embodiment of the present application uses the spatial state method instead of the direct integration method to calculate the damping force, which specifically includes:

[0099] The frequency domain delay function is constructed by using the additional mass coefficient and potential flow damping coefficient obtained by the potential flow frequency domain calculation software. The frequency domain delay function is identified by the frequency domain regression method to obtain the fitted transfer function.

[0100] Convert the transfer function into a state space representation to obtain the state space coefficients;

[0101] Construct a state-space model in OpenModelica and substitute the state-space coefficients into the state-space model to calculate the damping force.

[0102] The damping force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque converted from the damping force are transmitted to the wave energy float system model through Frame_b in OpenModelica.

[0103] It should be noted that the state space is expressed as follows:

[0104]

[0105] Where μ(t) is the state variable used to describe changes within the system, A is the n×n system matrix, B is the n×1 control matrix, C is the 1×n output matrix, D is the 1×1 direct transfer matrix, and n is the order of the high-order constant coefficient partial differential equation describing the system.

[0106] The general solution of the above formula is as follows:

[0107]

[0108] When the initial conditions , and input a unit pulse signal at the same time, that is , then the impulse response function (or kernel function) is as follows:

[0109]

[0110] Performing Laplace transform on the unit impulse response function yields the transfer function of the state-space model as follows:

[0111]

[0112] In fact, the state space is the matrix expression of the high-order partial differential equation converted into the first-order differential equation, which is equivalent to the high-order partial differential equation with constant coefficients. Combining the relationship between convolution and high-order partial differential equations, it can be understood that the state space and convolution describe the same system when the transfer function is the same. Therefore, the convolution calculation can be equivalently replaced by the state space model with the same transfer function. The additional mass coefficient A(ω) and the potential flow damping coefficient B(ω) can be obtained through the existing potential flow frequency domain calculation software. Then, it is necessary to reversely obtain H(s) through these coefficients A(ω) and B(ω). The solution idea is as follows: Figure 3 Specifically, by adding the mass system number A(ω) and the potential flow damping coefficient B(ω), the frequency-domain delay function K(jω) is obtained. The fitted transfer function K(s) is then obtained through system identification, which can be performed using frequency-domain regression. Finally, K(s) is converted to a state-space representation to obtain the state-space coefficients A, B, C, and D. Substituting these coefficients into the Modelica state-space model yields the damping force. The force and torque outputs of the damping force are identical to those of the previous submodules.

[0113] S7. Model the added mass calculation model using OpenModelica, calculate the added mass force based on the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and transmit the added mass force to the wave energy float system model.

[0114] Mass force F M The calculation formula is as follows:

[0115]

[0116] The appropriate impulse added mass matrix used in the true linear hydrodynamic load equations is not frequency dependent but is the infinite frequency limit of the frequency dependent added mass matrix. This limit exists for three-dimensional objects in general. The values of subscripts i and j range from 1 to 6; the six degrees of freedom of each float are 1 = surge, 2 = sway, 3 = heave, 4 = roll, 5 = pitch, and 6 = bow. Represents the six-degree-of-freedom acceleration of the j-th float, which is a 6*1 matrix. The elements in the matrix include the accelerations in the three directions of pitch, sway, and heave, and the angular accelerations in the three directions of roll, pitch, and yaw.

[0117] The acceleration and angular acceleration of the float transmitted by the wave energy float system model are received through the RealInput module in OpenModelica. The added mass value is set through the Gain module in OpenModelica. The RealInput module and the Gain module are connected to complete the multiplication of the acceleration, angular acceleration and the added mass, and the added mass force obtained by multiplying the acceleration, angular acceleration and the added mass is output. The added mass force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque converted from the added mass force are transmitted to the wave energy float system model through Frame_b in OpenModelica.

[0118] S8. Modeling a hydrostatic restoring force calculation model using OpenModelica, calculating the hydrostatic restoring force based on the displacement and angular displacement of the float transmitted by the wave energy float system model, and transmitting the hydrostatic restoring force to the wave energy float system model;

[0119] Linear hydrostatic restoring force of the float The calculation formula is:

[0120]

[0121] Where C is the linear static restoring stiffness; the subscripts i and j range from 1 to 6, and the six degrees of freedom of each float are 1 = surge, 2 = sway, 3 = heave, 4 = roll, 5 = pitch, and 6 = bow; q j is the displacement of the jth degree of freedom of the float, including three displacements in the directions of longitudinal, transverse and vertical swing, and three angular displacements in the directions of roll, pitch and yaw.

[0122] The displacement and angular displacement of the float transmitted by the wave energy float system model are received through the RealInput module in OpenModelica; the linear static restoring stiffness value is set through the Gain module in OpenModelica; the RealInput module and the Gain module are connected to complete the multiplication of the displacement, angular displacement and the linear static restoring stiffness value, and the hydrostatic restoring force obtained by multiplying the displacement, angular displacement and the linear static restoring stiffness value is output; the hydrostatic restoring force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque converted from the hydrostatic restoring force are transmitted to the wave energy float system model through Frame_b in OpenModelica.

[0123] S9. Set the simulation duration and time step, and solve the constructed model through the solver.

[0124] Using OpenModelica, the wave energy float model is decomposed into multiple submodels based on potential flow theory. The equations are then established by physically connecting the submodels. The simulation duration and time step are selected, and the solver automatically discretizes time and solves the system of equations.

[0125] In this application, OpenModelica is used to decompose the wave energy float model into multiple sub-models according to potential flow theory for modeling. Then, after the physical relationships of each sub-model are connected, the equation can be established. By selecting the simulation duration and time step, the solver will automatically discretize time and solve the equation group, which greatly reduces the steps in the physical modeling process and reduces the difficulty of solving the equation group, thereby reducing the complexity of the modeling process. In this application, each sub-model is abstracted into a class for separate modeling, and then the abstracted classes are connected to solve the problem of the entire system. After the connection, the equation is established. The solver will automatically discretize time and solve the equation group, which increases the scalability of the wave energy float model. The OpenModelica simulation platform used provides a graphical custom model corresponding to the class. The reuse of the graphical model greatly reduces the difficulty of reuse and reconstruction, thereby improving the reusability, reconfigurability and scalability of the time-domain simulation method of the wave energy float model.

[0126] Please refer to Figure 4 , an embodiment of the present application provides a time domain simulation device for a wave energy float model, comprising:

[0127] A decomposition unit is used to decompose the wave energy float model to obtain a gravity field model, a wave energy float system model, a wave force calculation model, a buoyancy calculation model, an added mass calculation model, a damping force calculation model, a hydrostatic restoring force calculation model, and a viscous force calculation model;

[0128] The simulation unit is used to model the decomposed sub-models using OpenModelica, establish connections between the sub-models, and solve the model using the solver.

[0129] The simulation unit is specifically used for:

[0130] Model the gravity field model using OpenModelica to determine the gravity field of each sub-model;

[0131] The truss structure connecting the wave energy float was modeled using OpenModelica. The spring stiffness and damper damping were set to simulate the effect of the energy harvesting device on the wave energy float. The displacement, velocity, acceleration, angular displacement, angular velocity, and angular acceleration of the float were monitored. The wave energy float system model was then connected to the remaining sub-models.

[0132] The buoyancy calculation model is modeled using OpenModelica to obtain the buoyancy and transfer the buoyancy to the wave energy float system model.

[0133] The viscous force calculation model is built using OpenModelica. The viscous force is calculated based on the velocity and angular velocity of the float transmitted by the wave energy float system model, and the viscous force is transmitted to the wave energy float system model.

[0134] The wave force calculation model is built using OpenModelica. The wave force is calculated based on the initial angle and displacement of the float transmitted by the wave energy float system model, and the wave force is transmitted to the wave energy float system model.

[0135] The damping force calculation model is modeled using OpenModelica to obtain the damping force, and the damping force is transferred to the wave energy buoy system model.

[0136] The added mass calculation model is modeled using OpenModelica. The added mass force is calculated based on the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and the added mass force is transmitted to the wave energy float system model.

[0137] The hydrostatic restoring force calculation model was built using OpenModelica. The hydrostatic restoring force was calculated based on the displacement and angular displacement of the float transmitted by the wave energy float system model, and the hydrostatic restoring force was transmitted to the wave energy float system model.

[0138] Set the simulation duration and time step, and use the solver to solve the constructed model.

[0139] In this application, OpenModelica is used to decompose the wave energy float model into multiple sub-models according to potential flow theory for modeling. Then, after the physical relationships of each sub-model are connected, the equation can be established. By selecting the simulation duration and time step, the solver will automatically discretize time and solve the equation group, which greatly reduces the steps in the physical modeling process and reduces the difficulty of solving the equation group, thereby reducing the complexity of the modeling process. In this application, each sub-model is abstracted into a class for separate modeling, and then the abstracted classes are connected to solve the problem of the entire system. After the connection, the equation is established. The solver will automatically discretize time and solve the equation group, which increases the scalability of the wave energy float model. The OpenModelica simulation platform used provides a graphical custom model corresponding to the class. The reuse of the graphical model greatly reduces the difficulty of reuse and reconstruction, thereby improving the reusability, reconfigurability and scalability of the time-domain simulation method of the wave energy float model.

[0140] An embodiment of the present application further provides an electronic device, the device including a processor and a memory;

[0141] The memory is used to store program codes and transmit the program codes to the processor;

[0142] The processor is configured to execute the time-domain simulation method of the wave energy buoy model in the aforementioned method embodiment according to the instructions in the program code.

[0143] An embodiment of the present application further provides a computer-readable storage medium for storing program code. When the program code is executed by a processor, the time-domain simulation method of the wave energy buoy model in the aforementioned method embodiment is implemented.

[0144] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0145] In the specification of this application and the above-mentioned drawings, the terms "first," "second," "third," "fourth," etc. (if any) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, product, or apparatus.

[0146] It should be understood that in this 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 can 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 previous and next associated objects are in an "or" relationship. "At least one of the following items" 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 plural.

[0147] In the several embodiments provided in this 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 merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, 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.

[0148] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0149] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0150] 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, 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. The computer software product is stored in a storage medium and includes several instructions for executing all or part of the steps of the method described in each embodiment of the present application through a computer device (which can be a personal computer, server, or network device, etc.). The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (full name: Read-Only Memory, English abbreviation: ROM), random access memory (full name: Random Access Memory, English abbreviation: RAM), disk or optical disk, and other media that can store program code.

[0151] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above 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 application.

Claims

1. A time domain simulation method for a wave energy float model, characterized in that: include: The wave energy float model is decomposed to obtain the gravity field model, wave energy float system model, wave force calculation model, buoyancy calculation model, added mass calculation model, damping force calculation model, hydrostatic restoring force calculation model, and viscous force calculation model; Use OpenModelica to model the decomposed sub-models and establish connections between them. Use the solver to solve the model, including: Modeling the gravity field model using OpenModelica to determine the gravity field where each sub-model is located; Use OpenModelica to model the truss structure connecting the wave energy float, set the spring stiffness and damper damping, monitor the float's displacement, velocity, acceleration, angular displacement, angular velocity, and angular acceleration, and establish connections between the wave energy float system model and the remaining sub-models. Modeling the buoyancy calculation model using OpenModelica to obtain buoyancy, and transferring the buoyancy to the wave energy float system model; Modeling the viscous force calculation model using OpenModelica, calculating the viscous force according to the velocity and angular velocity of the float transmitted by the wave energy float system model, and transmitting the viscous force to the wave energy float system model; Modeling the wave force calculation model using OpenModelica, calculating the wave force based on the initial angle and displacement of the float transmitted by the wave energy float system model, and transmitting the wave force to the wave energy float system model; Modeling the damping force calculation model using OpenModelica to obtain the damping force, and transmitting the damping force to the wave energy buoy system model; Modeling the added mass calculation model using OpenModelica, calculating the added mass force according to the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and transmitting the added mass force to the wave energy float system model; Modeling the hydrostatic restoring force calculation model using OpenModelica, calculating the hydrostatic restoring force based on the displacement and angular displacement of the float transmitted by the wave energy float system model, and transmitting the hydrostatic restoring force to the wave energy float system model; Set the simulation duration and time step, and use the solver to solve the constructed model.

2. The time domain simulation method of the wave energy buoy model according to claim 1 is characterized in that: Modeling the viscous force calculation model using OpenModelica, calculating the viscous force according to the velocity and angular velocity of the float transmitted by the wave energy float system model, and transmitting the viscous force to the wave energy float system model, including: The RealInput module in OpenModelica receives the velocity and angular velocity of the float transmitted by the wave energy float system model, and the Gain module in OpenModelica sets the damping value; Connect the RealInput module to the Gain module to output the viscous force obtained by multiplying the velocity, angular velocity and damping value; The Gain module is connected to the ForceAndTorque module in OpenModelica to convert the viscous force into force and torque, and the force and torque converted from the viscous force are transmitted to the wave energy float system model through Frame_b in OpenModelica.

3. The time domain simulation method of the wave energy buoy model according to claim 1 is characterized in that: The wave force calculation model is modeled using OpenModelica, the wave force is calculated according to the initial angle and displacement of the float transmitted by the wave energy float system model, and the wave force is transmitted to the wave energy float system model, including: Receive the initial angle and displacement of the float from the wave energy float system model through the RealInput module in OpenModelica; A wave force calculation model is constructed in OpenModelica, and the initial angle and displacement of the float are substituted into the wave force calculation model to calculate the wave force; The wave force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque obtained by the wave force conversion are transmitted to the wave energy buoy system model through Frame_b in OpenModelica.

4. The time domain simulation method of the wave energy buoy model according to claim 1, characterized in that: Modeling the damping force calculation model using OpenModelica to obtain the damping force, and transmitting the damping force to the wave energy buoy system model, including: receiving the velocity and angular velocity of the float transmitted by the wave energy float system model through the RealInput module in OpenModelica; A damping force calculation model is constructed in OpenModelica, and the velocity and angular velocity of the float are substituted into the damping force calculation model to calculate the damping force; The damping force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque converted from the damping force are transmitted to the wave energy buoy system model through Frame_b in OpenModelica.

5. The time domain simulation method of the wave energy buoy model according to claim 1 is characterized in that: Modeling the damping force calculation model using OpenModelica to obtain the damping force, and transmitting the damping force to the wave energy buoy system model, including: A frequency domain delay function is constructed using the additional mass coefficient and the potential flow damping coefficient obtained by the potential flow frequency domain calculation software, and the frequency domain delay function is identified by the frequency domain regression method to obtain a fitted transfer function; Converting the transfer function into a state-space representation to obtain state-space coefficients; Constructing a state-space model in OpenModelica, and substituting the state-space coefficients into the state-space model to calculate the damping force; The damping force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque converted from the damping force are transmitted to the wave energy buoy system model through Frame_b in OpenModelica.

6. The time domain simulation method of the wave energy buoy model according to claim 1, characterized in that: The added mass calculation model is modeled by OpenModelica, an added mass force is calculated according to the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and the added mass force is transmitted to the wave energy float system model, including: receiving the acceleration and angular acceleration of the float transmitted by the wave energy float system model through the RealInput module in OpenModelica; Set the added mass value through the Gain block in OpenModelica, connect the RealInput block to the Gain block, and output the added mass force obtained by multiplying the acceleration and angular acceleration by the added mass. The added mass force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque obtained by the added mass force conversion are transmitted to the wave energy buoy system model through Frame_b in OpenModelica.

7. The time domain simulation method of the wave energy buoy model according to claim 1, characterized in that: The hydrostatic restoring force calculation model is modeled using OpenModelica, the hydrostatic restoring force is calculated according to the displacement and angular displacement of the float transmitted by the wave energy float system model, and the hydrostatic restoring force is transmitted to the wave energy float system model, including: receiving the displacement and angular displacement of the float transmitted by the wave energy float system model through the RealInput module in OpenModelica; Set the linear statics restoring stiffness value through the Gain module in OpenModelica; Connect the RealInput module to the Gain module to output the hydrostatic restoring force obtained by multiplying the displacement and angular displacement by the linear static restoring stiffness value; The hydrostatic restoring force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque converted from the hydrostatic restoring force are transmitted to the wave energy buoy system model through Frame_b in OpenModelica.

8. A time domain simulation device for a wave energy float model, characterized in that: include: A decomposition unit is used to decompose the wave energy float model to obtain a gravity field model, a wave energy float system model, a wave force calculation model, a buoyancy calculation model, an added mass calculation model, a damping force calculation model, a hydrostatic restoring force calculation model, and a viscous force calculation model; The simulation unit is used to model the decomposed sub-models using OpenModelica, establish connections between the sub-models, and solve the model using the solver. The simulation unit is specifically used for: Modeling the gravity field model using OpenModelica to determine the gravity field where each sub-model is located; Use OpenModelica to model the truss structure connecting the wave energy float, set the spring stiffness and damper damping, monitor the float's displacement, velocity, acceleration, angular displacement, angular velocity, and angular acceleration, and establish connections between the wave energy float system model and the remaining sub-models. Modeling the buoyancy calculation model using OpenModelica to obtain buoyancy, and transferring the buoyancy to the wave energy float system model; Modeling the viscous force calculation model using OpenModelica, calculating the viscous force according to the velocity and angular velocity of the float transmitted by the wave energy float system model, and transmitting the viscous force to the wave energy float system model; Modeling the wave force calculation model using OpenModelica, calculating the wave force based on the initial angle and displacement of the float transmitted by the wave energy float system model, and transmitting the wave force to the wave energy float system model; Modeling the damping force calculation model using OpenModelica to obtain the damping force, and transmitting the damping force to the wave energy buoy system model; Modeling the added mass calculation model using OpenModelica, calculating the added mass force according to the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and transmitting the added mass force to the wave energy float system model; Modeling the hydrostatic restoring force calculation model using OpenModelica, calculating the hydrostatic restoring force based on the displacement and angular displacement of the float transmitted by the wave energy float system model, and transmitting the hydrostatic restoring force to the wave energy float system model; Set the simulation duration and time step, and use the solver to solve the constructed model.

9. An electronic device, characterized in that: The device includes a processor and a memory; The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the time-domain simulation method of the wave energy buoy model according to any one of claims 1 to 7 according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium is used to store program code, and when the program code is executed by the processor, the time-domain simulation method of the wave energy buoy model according to any one of claims 1 to 7 is implemented.

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