CN-121981025-A - Strong nonlinear simulation method and device suitable for large floating fan

CN121981025ACN 121981025 ACN121981025 ACN 121981025ACN-121981025-A

Abstract

The application provides a strong nonlinear simulation method and a strong nonlinear simulation device suitable for a large-scale floating fan, wherein the method comprises the steps of dividing a target floating fan into a plurality of body structures according to model parameters of the target floating fan, constructing a multi-body model comprising a plurality of degrees of freedom, building a whole machine load and a motion transmission path, calculating pneumatic load input of each body structure, calculating nonlinear power response of a blade according to the pneumatic load input of each body structure, converting the nonlinear power response of the blade into a whole coordinate system through the coordinate transformation relation, inputting the whole coordinate system into a multi-body power model of the whole machine, and calculating generalized main power and generalized inertial force of each body structure in the target floating fan to obtain the motion response of each body structure of the target floating fan through simultaneous solving. Through the scheme, the motion response of each body structure of the target floating fan can be accurately determined, so that the running state of the floating fan in the deep-open sea complex environment can be accurately estimated.

Inventors

ZHOU BINZHEN
YU KUN
XIE ZHANLI
LIU SIYUAN
XIA ZHONGBANG
LIU QIANHUA
LU JIANHUA
WANG TAO
Xiang Ruoxuan
WANG ZEDONG
WU XIUSHAN
HU JIANJIAN
ZHOU ZHAOMIN
JIN PENG
YANG LI

Assignees

中电建新能源集团股份有限公司
华南理工大学
中电建(万宁)新能源有限公司

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (14)

1. The strong nonlinear simulation method suitable for the large floating fan is characterized by comprising the following steps of: Obtaining model parameters of a target floating fan, wherein the model parameters comprise at least one of shape parameters and quality parameters; dividing the target floating fan into a plurality of body structures according to the model parameters to construct a multi-body model comprising a plurality of degrees of freedom and establish a complete machine load and motion transmission path, wherein the plurality of body structures comprise at least one of blades, wind wheels, cabins, main shafts, yaw bearings, towers and floating platforms; according to the relative position relation of each body structure in the target floating fan, respectively establishing a local coordinate system of each body structure, and establishing a coordinate transformation relation of all body structures of the whole machine from the local to the global coordinate system by taking the origin of the bottom of the tower as the reference origin of the global coordinate system; calculating the pneumatic load input of each body structure, and calculating the nonlinear power response of the blade according to the pneumatic load input of each body structure; And converting nonlinear power response of the blade into an integral coordinate system through the coordinate transformation relation, inputting the integral coordinate system into a multi-body power model of the whole machine, and calculating to obtain generalized main power and generalized inertia force of each body structure in the target floating fan so as to obtain motion response of each body structure of the target floating fan through simultaneous solving.
2. The method of claim 1, wherein calculating the aerodynamic load input for each body structure comprises: acquiring wind condition parameters of the target floating fan operation area; Establishing a free vortex trail reinforced vortex lattice pneumatic model of the blade; based on the free vortex trail reinforced vortex lattice pneumatic model of the blades and the wind condition parameters, calculating unsteady pneumatic loads of three blades of the wind wheel respectively; Transforming the unsteady pneumatic load coordinates of the three blades to a wind wheel coordinate system for superposition to obtain the pneumatic load of the wind wheel; And sequentially transforming the pneumatic load of the wind wheel to each body structure in coordinates to serve as the pneumatic load input of each body structure.
3. The method of claim 2, wherein calculating a nonlinear power response of the blade based on aerodynamic load inputs of the individual structures comprises: obtaining structural parameters of the blade; Constructing a nonlinear control equation of the blade according to the nonlinear power model of the long and flexible blade and the structural parameters of the blade; and according to the nonlinear control equation, combining the unsteady aerodynamic load of the blade and the gravity and inertial force loads of the blade, and carrying out iterative solution to obtain the nonlinear dynamic response of the blade.
4. The method of claim 2, wherein establishing a free vortex trail enhanced vortex lattice pneumatic model of the blade comprises: calculating the induction speed of the vortex on the blade control point according to the evolution and the mutual influence of the blade attachment vortex and the wake vortex; Converting the free inflow wind and the rigid motion speed of the target floating fan under the integral coordinate system into a blade coordinate system, and obtaining the total speed at the control point through the free inflow wind speed, the rigid motion speed of the fan and the elastic deformation speed of the blade: ; Wherein, the To control the overall speed at the point of control, For the free-flowing wind speed, Is the rigid body motion speed of the fan, For the rate of elastic deformation of the blade, For the induction speed, i represents the i-th control point of the blade lifting surface vortex lattice; based on the impermeable boundary hypothesis, determining a aerodynamic coefficient matrix of influence of the attached vortex and the wake vortex on the induction speed of the control point; establishing a speed equation at a control point according to the pneumatic coefficient matrix, and calculating the adhesive vortex strength according to the speed equation ; The unsteady aerodynamic lift and unsteady aerodynamic drag of the blade are calculated according to the following formula: ; ; Wherein, the For the unsteady aerodynamic lift of the blade, For the blade to be in an unsteady aerodynamic drag, In order to achieve an air density of the air, For the chord length of the airfoil shape, In order to have a viscous aerodynamic lift coefficient, In order for the airfoil to have an effective angle of attack, In order to have a viscous aerodynamic drag coefficient, For the length of the unit where the airfoil is located, Based on the adhesive vortex strength The calculated unsteady induced drag, j, represents the j-th wake shed from the trailing edge of the blade.
5. The method of claim 4, wherein obtaining the viscous aerodynamic lift coefficient and the viscous aerodynamic drag coefficient comprises: the effective angle of attack of the airfoil is calculated according to the following formula: ; ; Wherein, the In order for the airfoil to have an effective angle of attack, Is the influence of the variable pitch control of the fan on the attack angle, The lift force is induced for the blade unstably, Is the airfoil lift coefficient; and carrying out table lookup matching on two-dimensional wing profile wind tunnel data through the effective attack angle of the wing profile to obtain a viscous aerodynamic lift coefficient and a viscous aerodynamic drag coefficient.
6. A method according to claim 3, wherein iteratively solving for a nonlinear power response of the blade in combination with an unsteady aerodynamic load of the blade and gravity and inertial loads of the blade according to the nonlinear control equation comprises: According to structural parameters of the blade, a tangential stiffness matrix of the blade structure is established by deducing a second-order transverse and longitudinal displacement field and Green strain: ; Wherein, the In the form of a tangential stiffness matrix, In the form of a linear stiffness portion, In the case of a portion with a large deformation rigidity, Is a centrifugal tempering part; Acquiring the quality parameters of the blade, and determining a quality matrix and a structural damping matrix of the blade according to the quality parameters of the blade; Obtaining an external load according to the pneumatic load plus the gravity load and the inertial load of the blade; according to the external load, the tangential stiffness matrix, the mass matrix and the structural damping matrix, a nonlinear control equation of the blade for describing the structural large deformation is established: ; Wherein, the Representing the displacement acceleration of the blade, Indicating the speed of displacement of the blade, Representing the increment of the displacement of the blade, For the purpose of an external load, In the form of a tangential stiffness matrix, In the form of a quality matrix, Is a structural damping matrix; deriving a follow-up coordinate system by a co-rotation coordinate method; establishing a co-rotation transformation relation between a coordinate system of an internal unit of the blade and an integral coordinate system according to the follow-up coordinate system, wherein the co-rotation transformation relation is used for realizing the large rotation description of the blade: ; Wherein, the Representing the follow-up coordinate system, is a coordinate transformation matrix from the unit coordinate system to the whole coordinate system, Representing a tangential stiffness matrix of the blade unit; Time-step integration is performed by a nonlinear Newmark-beta method under the framework of a modified Lagrangian method, and nonlinear dynamic response of the blade is iteratively solved by a Newton-Raphson method in each time step.
7. The method of claim 1, further comprising, after calculating the aerodynamic load input for each volume structure: acquiring wave parameters; calculating irregular incident waves acting on the floating platform based on Gao Jiepu models and the wave parameters; and calculating the nonlinear wave hydrodynamic force of the floating platform under the interaction of the inner domain waves based on the time domain full nonlinear potential flow theory and the high-order boundary element method.
8. The method of claim 7, wherein calculating an irregularly incident wave acting on the floating platform based on the Gao Jiepu model and the wave parameters comprises: solving nonlinear free surface boundary conditions by pseudo-spectrometry to generate an incident wave field containing modulation instability: ; ; Wherein, the In order to achieve a vertical velocity of the steel, In the case of a convection term, In order to be a static pressure recovery term, Is a dynamic pressure term, which is used for the dynamic pressure, As a non-linear coupling term, Is an incident wave field; three-dimensional reconstruction is carried out on the incident wave field so as to obtain the horizontal velocity and the horizontal velocity of the incident wave: ; ; Wherein, the For the horizontal velocity of the incident wave, Is a vector of the horizontal position of the object, At the level of the speed of the machine, Is an inverse two-dimensional fourier transform, Is a vector of horizontal wavenumbers, , In order to calculate the hyperbolic tangent value, Is a three-dimensional velocity potential spectrum, Is the incident wave velocity field; the incident wave velocity field is interpolated to an inner domain boundary to determine the effect of the wave field outer domain nonlinear evolution on the inner domain nonlinear hydrodynamic force.
9. The method of claim 7, wherein calculating the nonlinear wave hydrodynamics of the floating platform under the in-domain wave interactions based on the time-domain full nonlinear potential flow theory and the high-order boundary element method comprises: Establishing a boundary integral equation: ; Wherein, the For the velocity potential at the field point P, For the self-influence of the velocity potential at the field point P, Is a function of the Rankine green's function, For the boundary velocity potential profile, As a boundary normal velocity disturbance, For boundary tangential velocity disturbances, The coefficient of the fixed angle is represented by, The field point is indicated as such, The velocity potential is represented by a velocity profile, The source point is represented by a reference numeral, The function of the green's is represented, Representing the normal derivative along the boundary, Representing the integral boundary where the source point is located; discretizing a boundary integral equation by a high-order boundary element method; calculating scattering potential through the boundary integral equation; calculating a total velocity potential from the scattering potential; The acceleration potential is calculated by the total velocity potential: ; Wherein, the In the form of an acceleration potential, In order to be a potential for a total velocity, For normal acceleration caused by the motion of the floating platform, For interaction of floating platform motion with fluid velocity gradients, For the reference frame rotation correction, Is the true flow rate of the fluid particles, Is the translational acceleration of the floating platform, For the rotational speed of the floating platform, For the rotational acceleration of the floating platform, Is the position vector of the floating platform object plane, Is the unit normal vector of the floating platform; calculating nonlinear wave hydrodynamic force of the floating platform according to the acceleration potential: ; Wherein, the Representing the nonlinear wave hydrodynamic forces of the floating platform, In order to achieve an air density of the air, A unit normal vector representing the integration boundary, Indicating the integration boundary at which the field point is located, For the hydrostatic distribution caused by the force of gravity of the fluid, A pressure term representing the conversion of fluid kinetic energy.
10. The method of any one of claims 7 to 9, further comprising, after calculating the nonlinear wave hydrodynamics of the floating platform under in-domain wave interactions based on time-domain full nonlinear potential flow theory and high-order boundary element method: Acquiring the motion speed and the motion acceleration of the floating platform of the last time step; Converting the motion speed and the motion acceleration of the floating platform of the last time step into the origin of the tower bottom through coordinate transformation so as to calculate the motion response of each structure of the target floating fan under the motion of the floating platform according to the multi-body dynamics equation of the current time step; the total tower bottom load calculated by taking pneumatic load, inertial force load, gravity load and damping load into consideration in the current time step is transferred to a platform reference point through coordinate transformation; and inputting the nonlinear wave hydrodynamic force, the viscous damping force and the mooring load of the floating platform into a platform coupling motion equation, and calculating to obtain the motion response of the floating platform.
11. Strong nonlinear simulation device suitable for large-scale floating fan, characterized by comprising: The acquisition module is used for acquiring model parameters of the target floating fan, wherein the model parameters comprise at least one of shape parameters and quality parameters; the building module is used for dividing the target floating fan into a plurality of body structures according to the model parameters so as to build a multi-body model comprising a plurality of degrees of freedom and build a whole machine load and motion transmission path, wherein the plurality of body structures comprise at least one of blades, wind wheels, cabins, main shafts, yaw bearings, towers and floating platforms; the building module is used for respectively building a local coordinate system of each body structure according to the relative position relation of each body structure in the target floating fan, taking the origin of the bottom of the tower as the reference origin of the whole coordinate system, and building a coordinate transformation relation of all body structures of the whole machine from the local to the whole coordinate system; the first calculation module is used for calculating the pneumatic load input of each body structure and calculating the nonlinear power response of the blade according to the pneumatic load input of each body structure; The second calculation module is used for converting nonlinear power response of the blade into an integral coordinate system through the coordinate transformation relation and inputting the integral coordinate system into a multi-body power model of the whole machine, and calculating to obtain generalized main power and generalized inertia force of each body structure in the target floating fan so as to obtain motion response of each body structure of the target floating fan through simultaneous solving.
12. A terminal device comprising a processor and a memory for storing processor executable instructions, characterized in that the processor, when executing the instructions, implements the steps of the method of any one of claims 1 to 10.
13. A computer readable storage medium having stored thereon a computer program/instruction, which when executed by a processor, implements the steps of the method of any of claims 1 to 10.
14. A computer program product comprising computer programs/instructions which, when executed by a processor, implement the steps of the method of any one of claims 1 to 10.

Description

Strong nonlinear simulation method and device suitable for large floating fan Technical Field The application belongs to the technical field of integrated simulation of offshore wind power equipment, and particularly relates to a strong nonlinear simulation method and device suitable for a large floating fan. Background As offshore wind power development gradually extends to deep ocean, floating fans are an important development direction. In order to improve the unit installed capacity and reduce the electricity cost, the wind turbine is rapidly developed to be large-scale, the single machine power reaches 20MW, and the blade length can reach more than hundred meters. The super-long flexible blade generally adopts a lightweight design, has reduced rigidity, is easy to generate large deformation and large rotation, has obvious geometrical nonlinear effect, and has higher requirements on the calculation accuracy of the aeroelasticity. Further, the complex wind and wave environment in deep open sea brings stronger unsteady pneumatic and hydrodynamic coupling effect. The offshore wind field has non-uniform turbulence characteristics, the wind turbine wake flow evolves and has obvious interaction, and the wave environment not only contains regular waves and random waves, but also can generate extreme waves to induce the strong nonlinear motion and coupling response of the platform. The existing aerodynamic model is often based on a phyllin-momentum theory method, the unsteady inflow and wake effects are difficult to capture, most of the commonly used structural dynamics models assume small deformation and cannot accurately describe nonlinear aeroelastic characteristics of long and flexible blades, and in the aspect of hydrodynamic analysis, the frequency domain potential flow theory is insufficient in precision under extreme sea conditions, so that the engineering efficiency and the real reflection of nonlinear response are difficult to be simultaneously considered. Aiming at how to control the multi-field coupling effect, the accuracy of motion response of each body structure of the target floating fan is improved, and no effective solution is proposed at present. Disclosure of Invention The application aims to provide a strong nonlinear simulation method and a device suitable for a large floating fan, which can improve the accuracy of motion response of each body structure of a target floating fan. The application provides a strong nonlinear simulation method and a device suitable for a large floating fan, which are realized as follows: a strong nonlinear simulation method suitable for a large floating fan, the method comprising: Obtaining model parameters of a target floating fan, wherein the model parameters comprise at least one of shape parameters and quality parameters; dividing the target floating fan into a plurality of body structures according to the model parameters to construct a multi-body model comprising a plurality of degrees of freedom and establish a complete machine load and motion transmission path, wherein the plurality of body structures comprise at least one of blades, wind wheels, cabins, main shafts, yaw bearings, towers and floating platforms; according to the relative position relation of each body structure in the target floating fan, respectively establishing a local coordinate system of each body structure, and establishing a coordinate transformation relation of all body structures of the whole machine from the local to the global coordinate system by taking the origin of the bottom of the tower as the reference origin of the global coordinate system; calculating the pneumatic load input of each body structure, and calculating the nonlinear power response of the blade according to the pneumatic load input of each body structure; And converting nonlinear power response of the blade into an integral coordinate system through the coordinate transformation relation, inputting the integral coordinate system into a multi-body power model of the whole machine, and calculating to obtain generalized main power and generalized inertia force of each body structure in the target floating fan so as to obtain motion response of each body structure of the target floating fan through simultaneous solving. In one embodiment, calculating aerodynamic load inputs for each body structure includes: acquiring wind condition parameters of the target floating fan operation area; Establishing a free vortex trail reinforced vortex lattice pneumatic model of the blade; based on the free vortex trail reinforced vortex lattice pneumatic model of the blades and the wind condition parameters, calculating unsteady pneumatic loads of three blades of the wind wheel respectively; Transforming the unsteady pneumatic load coordinates of the three blades to a wind wheel coordinate system for superposition to obtain the pneumatic load of the wind wheel; And sequentially transforming the pneumatic load of the wind wheel