Wave energy floater model time domain simulation method and related device

Abstract

The invention discloses a wave energy floater model time domain simulation method and a related device, and the method comprises the steps: carrying out the decomposition of a wave energy floater model, a gravity field model, a wave energy floater system model, a wave force calculation model, a buoyancy calculation model, an additional mass calculation model, a damping force calculation model, a still water restoring force calculation model and a viscous force calculation model are obtained; modeling is carried out on the sub-models obtained through decomposition through OpenModelica, a connection relation is established for the sub-models, and the model is solved through a solver. According to the method, the wave energy floater model is decomposed into a plurality of sub-models for modeling according to the potential flow theory, then the equation equation can be established after the physical relations of the sub-models are connected, the equation set is solved through the solver, the steps in the physical modeling process are greatly reduced, the difficulty of solving the equation set is reduced, and the modeling efficiency is improved. The reusability, the reconfigurability and the expandability of the wave energy floater model time domain simulation method are improved.

Description

Technical Field

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

[0002] Wave energy is a renewable energy source with a wide distribution range and high energy density. Wave power generation technology can convert the kinetic energy in waves into electrical energy, which is a clean and environmentally friendly way of generating electricity. Before the wave energy device is put into use, it is necessary to simulate the wave energy device to evaluate its performance and optimize the design of the wave energy float.

[0003] At present, when performing time domain simulation on wave energy buoy models, most of the existing technologies adopt the idea of ​​procedural modeling (causal modeling), using languages ​​such as Fortran and C to model and solve the wave energy buoy model. Although it meets the actual engineering needs, for engineers, they not only need to master the mathematical derivation and process decomposition of the wave energy buoy model, but also need to clarify the solution order, system decoupling and solution processes, which greatly increases the workload; and the reusability, reconfigurability and scalability of the existing simulation methods are poor. 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, the wave energy float system model, the wave force calculation model, the buoyancy calculation model, the added mass calculation model, the damping force calculation model, the hydrostatic restoring force calculation model, and the viscous force calculation model;

[0007] Use OpenModelica to build models for each sub-model obtained by decomposition and establish connections between each sub-model. Use the solver to solve the model, including:

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

[0009] The truss structure connecting the wave energy float is modeled by OpenModelica, the spring stiffness and the damper damping are set, the displacement, velocity, acceleration, angular displacement, angular velocity and angular acceleration of the float are calculated by setting the relevant parameters of the float, and the wave energy float system model is connected with the remaining sub-models;

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

[0011] Modeling the viscous force calculation model through 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 through 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;

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

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

[0015] Modeling the hydrostatic restoring force calculation model through OpenModelica, calculating the hydrostatic restoring force according to 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, the viscous force calculation model is modeled by OpenModelica, the viscous force is calculated according to 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, including:

[0018] The velocity and angular velocity of the float transmitted by the wave energy float system model are received through the RealInput module in OpenModelica, and the damping value is set through the Gain module in OpenModelica;

[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 buoy system model through Frame_b in OpenModelica.

[0021] Optionally, the wave force calculation model is modeled by 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:

[0022] The initial angle and displacement of the float are received 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, the damping force calculation model is modeled by OpenModelica to obtain the damping force, and the damping force is transmitted to the wave energy buoy system model, including:

[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, the damping force calculation model is modeled by OpenModelica to obtain the damping force, and the damping force is transmitted to the wave energy buoy system model, including:

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

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

[0032] Constructing a state space model in OpenModelica, 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 additional mass calculation model through OpenModelica, calculating the additional mass force according to the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and transmitting the additional mass force to the wave energy float system model, including:

[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 module in OpenModelica, connect the RealInput module to the Gain module, and output the added mass force obtained by multiplying the acceleration and angular acceleration with the added mass;

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

[0038] Optionally, the hydrostatic restoring force calculation model is modeled by 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, angular displacement and 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] The 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 each sub-model obtained by decomposition through OpenModelica and establish connection relationships between each sub-model, and solve the model through the solver;

[0046] The simulation unit is specifically used for:

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

[0048] The truss structure connecting the wave energy float is modeled by OpenModelica, the spring stiffness and the damper damping are set, the displacement, velocity, acceleration, angular displacement, angular velocity and angular acceleration of the float are calculated by setting the relevant parameters of the float, and the wave energy float system model is connected with the remaining sub-models;

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

[0050] Modeling the viscous force calculation model through 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 through 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;

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

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

[0054] Modeling the hydrostatic restoring force calculation model through OpenModelica, calculating the hydrostatic restoring force according to 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 used to execute the time domain simulation method of the wave energy buoy model described in any one of the first aspects according to the instructions in the program code.

[0059] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store program code, and when the program code is executed by a processor, the time-domain simulation method of the wave energy buoy model described in 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 of the wave energy float model provided in the present application uses OpenModelica to decompose the wave energy float model into multiple sub-models according to the potential flow theory for modeling, and then after the physical relationship of each sub-model is connected, the equation can be established. Select the simulation duration and time step, the solver will automatically discretize the 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, reducing the complexity of the modeling process; the present application abstracts each sub-model into a class for separate modeling, and then connects the abstracted class to solve the problem of the entire system. After the connection, the equation is established, and the solver will automatically discretize the 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, and 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. 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 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 the embodiment of the present application;

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

[0067] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field 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 of a wave energy buoy model, comprising:

[0069] Step 110, decompose the wave energy buoy model to obtain a gravity field model, a wave energy buoy 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 decomposition through OpenModelica and establish a connection relationship between each sub-model, and solve the model through a solver.

[0072] The coupled solution model is the overall model, which can also be understood as the main function, where the calls, data transmission and coupling calculations of various modules are mainly performed. After modeling the decomposed sub-models through OpenModelica and connecting the sub-models, the simulation duration and time step are selected, and the solver is used to solve the problem. The Runge-Kutta method can be used for solving the problem.

[0073] Among them, OpenModelica is used to model each sub-model obtained by decomposition and establish a connection relationship between each sub-model. The specific process of solving the model through the solver includes:

[0074] S1. Model the gravity field model through 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 in 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 connected to the wave energy float through OpenModelica, set the spring stiffness and damper damping, monitor the displacement, velocity, acceleration, angular displacement, angular velocity and angular acceleration of the float, and establish a connection relationship 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 damping model. The wave energy float can use the BodyShape module in OpenModelica, in which the target parameters such as the mass, center of gravity, and moment of inertia of the float can be input, and the target parameters such as the initial displacement and initial angle can also be set. In the wave energy float system model, the Sensors module in OpenModelica is used to monitor the displacement, velocity, acceleration, angular displacement, angular velocity, and angular acceleration of the float, and the RealOutput module is used to output these parameters as parameters for calculation of other sub-models.

[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 an energy harvesting equivalent module for the wave energy float to simulate the effect of the energy harvesting device on the wave energy float. Establish a connection relationship between the wave energy float system model and the remaining sub-models, such as Figure 2 shown.

[0080] S3, the buoyancy calculation model is modeled through OpenModelica to obtain the buoyancy, and the buoyancy is transferred to the wave energy float system model;

[0081] The buoyancy calculation model uses a sub-model that simulates buoyancy. The buoyancy of the object is input into this sub-model, and the buoyancy can be calculated by the Archimedean principle. This sub-model loads the buoyancy onto the object in the coupled calculation, that is, transfers it to the wave energy buoy system model. The buoyancy value is input into the Constant module in OpenModelica, and it is connected to the WorldForce module in OpenModelica, that is, the buoyancy is converted into force, and then the force is output to the wave energy buoy system model using Frame_b in OpenModelica.

[0082] S4. Modeling the viscous force calculation model through 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;

[0083] The viscosity calculation model is used to calculate the viscosity 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. The embodiment of the present application adopts viscosity correction to consider the viscous damping force in the floating structure. The viscosity force F 黏 The calculation process is:

[0084]

[0085] In the formula, is the speed of the jth degree of freedom of the float; the value range of the subscript j is 1~6; the six degrees of freedom of the float are 1 = longitudinal swing, 2 = transverse swing, 3 = heave swing, 4 = roll, 5 = pitch, 6 = bow swing; is the matrix composed of the velocity and angular velocity of the float, It is a 6*1 matrix, the elements of which 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 velocity and angular velocity transmitted by the wave energy buoy system model are received through the RealInput module in OpenModelica. The viscous damping value is input into the Gain module in OpenModelica. The RealInput module is connected to the Gain module to complete the multiplication of the velocity, angular velocity and viscous damping to obtain the viscous force. The Gain module is connected to the ForceAndTorque module in OpenModelica to convert the viscous force into force and torque, and then the Frame_b in OpenModelica can be used to output the force and torque to the wave energy buoy system model.

[0087] S5. Model the wave force calculation model through OpenModelica, calculate the wave force according to 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. A wave force calculation model is built 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 duration, Indicates the phase of the wave function, N is the number of times the wave function is divided, and indicates the simulation accuracy of the wave function. N can be customized. The calculated wave force can be converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque converted from the wave force are transmitted to the wave energy buoy system model using Frame_b in OpenModelica.

[0091] S6. Model the damping force calculation model through OpenModelica to obtain the damping force, and transfer the damping force to the wave energy buoy 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] Receive the velocity and angular velocity of the float transmitted by the wave energy float system model through the RealInput module in OpenModelica;

[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 time, 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 buoy 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 using the direct integration method to calculate the damping force 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, and 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 buoy system model through Frame_b in OpenModelica.

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

[0104]

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

[0106] The general solution of the above equation 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] By performing Laplace transform on the unit impulse response function, the transfer function of the state space model can be obtained 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 As shown, specifically, the frequency domain delay function K(jω) is obtained by adding the mass system quantity A(ω) and the potential flow damping coefficient B(ω), and then the fitted transfer function K(s) is obtained by system identification. The system identification can use the frequency domain regression method. Finally, K(s) is converted into a state space representation to obtain the state space coefficients A, B, C, D. These coefficients A, B, C, D are substituted into the state space model of Modelica to obtain the damping force. The force and torque output of the damping force are the same as those of the previous submodules.

[0113] S7. Modeling the additional mass calculation model through OpenModelica, calculating the additional mass force according to the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and transmitting the additional 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 the subscripts i and j range from 1 to 6; the six degrees of freedom of each float are 1 = longitudinal swing, 2 = transverse swing, 3 = vertical swing, 4 = roll, 5 = pitch, and 6 = bow swing; 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 surge, 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, and the RealInput module is connected to the Gain module 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 through OpenModelica, calculating the hydrostatic restoring force according to 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 float The calculation formula is:

[0120]

[0121] Where C is the linear static restoring stiffness; the value range of subscripts i and j is 1~6, and the six degrees of freedom of each float are 1 = longitudinal swing, 2 = transverse swing, 3 = heave swing, 4 = roll, 5 = pitch, and 6 = bow swing; q j is the displacement of the j-th 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 is connected with the Gain module 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] OpenModelica is used to decompose the wave energy float model into multiple sub-models according to the potential flow theory, and then the equations can be established after the physical relationships of each sub-model are connected. Select the simulation duration and time step, and the solver will automatically discretize the time and solve the equations.

[0125] In this application, the wave energy float model is decomposed into multiple sub-models according to the potential flow theory by using OpenModelica for modeling, and then the equations can be established after the physical relationships of each sub-model are connected. Select the simulation duration and time step, and the solver will automatically discretize the time and solve the equations, which greatly reduces the steps in the physical modeling process and reduces the difficulty of solving the equations, 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, the equation is established, and the solver will automatically discretize the time and solve the equations, which increases the scalability of the wave energy float model; the OpenModelica simulation platform used provides a graphical custom model corresponding to the class, and 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 , a wave energy buoy model time domain simulation device provided in an embodiment of the present application includes:

[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 each sub-model obtained by decomposition through OpenModelica and establish connection relationships between each sub-model, and solve the model through the solver;

[0129] The simulation unit is specifically used for:

[0130] The gravity field model is modeled through OpenModelica to determine the gravity field where each sub-model is located;

[0131] The truss structure connecting the wave energy float was modeled through OpenModelica, and 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, and the wave energy float system model was connected with the remaining sub-models.

[0132] The buoyancy calculation model is modeled through OpenModelica to obtain the buoyancy and pass the buoyancy to the wave energy float system model;

[0133] The viscous force calculation model is modeled by OpenModelica, the viscous force is calculated according to 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 modeled by 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;

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

[0136] The additional mass calculation model is modeled by OpenModelica, the additional mass force is calculated according to the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and the additional mass force is transmitted to the wave energy float system model;

[0137] The hydrostatic restoring force calculation model is built through 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;

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

[0139] In this application, the wave energy float model is decomposed into multiple sub-models according to the potential flow theory by using OpenModelica for modeling, and then the equations can be established after the physical relationships of each sub-model are connected. Select the simulation duration and time step, and the solver will automatically discretize the time and solve the equations, which greatly reduces the steps in the physical modeling process and reduces the difficulty of solving the equations, 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, the equation is established, and the solver will automatically discretize the time and solve the equations, which increases the scalability of the wave energy float model; the OpenModelica simulation platform used provides a graphical custom model corresponding to the class, and 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] The embodiment of the present application also provides an electronic device, the device comprising a processor and a memory;

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

[0142] The processor is used 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] The embodiment of the present application also provides a computer-readable storage medium, which is used to store 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 can 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] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of this application and the above-mentioned drawings 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 device that includes 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.

[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 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.

[0147] 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 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.

[0148] The units described 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.

[0149] 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.

[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 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. The computer software product is stored in a storage medium, including a number of 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 in English: Read-Only Memory, English abbreviation: ROM), random access memory (full name in English: Random Access Memory, English abbreviation: RAM), disk or optical disk and other media that can store program codes.

[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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A time domain simulation method for a wave energy buoy model, characterized in that: include: The wave energy float model is decomposed to obtain the gravity field model, the wave energy float system model, the wave force calculation model, the buoyancy calculation model, the added mass calculation model, the damping force calculation model, the hydrostatic restoring force calculation model, and the viscous force calculation model; Use OpenModelica to build models for each sub-model obtained by decomposition and establish connections between each sub-model. Use the solver to solve the model, including: Modeling the gravity field model through OpenModelica to determine the gravity field where each sub-model is located; Model the truss structure connected to the wave energy float through OpenModelica, set the spring stiffness and damper damping, monitor the displacement, velocity, acceleration, angular displacement, angular velocity and angular acceleration of the float, and establish a connection relationship between the wave energy float system model and the remaining sub-models; Modeling the buoyancy calculation model through OpenModelica to obtain buoyancy, and transferring the buoyancy to the wave energy buoy system model; Modeling the viscous force calculation model through 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 through 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; Modeling the damping force calculation model through OpenModelica to obtain the damping force, and transmitting the damping force to the wave energy buoy system model; Modeling the additional mass calculation model through OpenModelica, calculating the additional mass force according to the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and transmitting the additional mass force to the wave energy float system model; Modeling the hydrostatic restoring force calculation model through OpenModelica, calculating the hydrostatic restoring force according to 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: The viscous force calculation model is modeled by OpenModelica, the viscous force is calculated according to 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, including: The velocity and angular velocity of the float transmitted by the wave energy float system model are received through the RealInput module in OpenModelica, and the damping value is set through the Gain module in OpenModelica; 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 buoy 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 by 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: The initial angle and displacement of the float are received 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 is characterized in that: The damping force calculation model is modeled by OpenModelica to obtain the damping force, and the damping force is transmitted 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: The damping force calculation model is modeled by OpenModelica to obtain the damping force, and the damping force is transmitted to the wave energy buoy system model, including: A frequency domain delay function is constructed by using an additional mass coefficient and a potential flow damping coefficient obtained by a potential flow frequency domain calculation software, and a fitting transfer function is obtained by identifying the frequency domain delay function by using a frequency domain regression method; Converting the transfer function into a state space representation to obtain state space coefficients; Constructing a state space model in OpenModelica, 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 is characterized in that: The additional mass calculation model is modeled by OpenModelica, the additional mass force is calculated according to the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and the additional 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 module in OpenModelica, connect the RealInput module to the Gain module, and output the added mass force obtained by multiplying the acceleration and angular acceleration with the added mass; The additional mass force is converted into force and torque through the ForceAndTorque module in OpenModelica, and then the force and torque converted from the additional mass force 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 is characterized in that: The hydrostatic restoring force calculation model is modeled by 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, angular displacement and 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 buoy 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 each sub-model obtained by decomposition through OpenModelica and establish connection relationships between each sub-model, and solve the model through the solver; The simulation unit is specifically used for: Modeling the gravity field model through OpenModelica to determine the gravity field where each sub-model is located; Model the truss structure connected to the wave energy float through OpenModelica, set the spring stiffness and damper damping, monitor the displacement, velocity, acceleration, angular displacement, angular velocity and angular acceleration of the float, and establish a connection relationship between the wave energy float system model and the remaining sub-models; Modeling the buoyancy calculation model through OpenModelica to obtain buoyancy, and transferring the buoyancy to the wave energy buoy system model; Modeling the viscous force calculation model through 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 through 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; Modeling the damping force calculation model through OpenModelica to obtain the damping force, and transmitting the damping force to the wave energy buoy system model; Modeling the additional mass calculation model through OpenModelica, calculating the additional mass force according to the acceleration and angular acceleration of the float transmitted by the wave energy float system model, and transmitting the additional mass force to the wave energy float system model; Modeling the hydrostatic restoring force calculation model through OpenModelica, calculating the hydrostatic restoring force according to 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 comprises 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 1-7 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 codes, and when the program codes are executed by a processor, the time-domain simulation method for a wave energy buoy model according to any one of claims 1 to 7 is implemented.

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