CN-121997805-A - Marine fan refined integral coupling calculation method under wind-ice combined effect

CN121997805ACN 121997805 ACN121997805 ACN 121997805ACN-121997805-A

Abstract

The invention discloses a method for calculating refined integral coupling of an offshore wind turbine under the combined action of wind and ice, and belongs to the technical field of structural calculation of offshore wind turbines. The method is based on structural power nonlinearity, pile-soil interaction, aerodynamic load and aerodynamic damping effect, fluid-solid coupling and sea ice breaking failure modes, achieves wind-water-ice-soil-fan structure integrated coupling reaction analysis, and achieves integral refined coupling calculation of offshore fan ice-induced vibration by taking FAST and ANSYS/LS-DYNA as platforms, and obtains dynamic ice load and structural power response time. The invention can accurately and perfectly estimate the ice vibration response and the dynamic ice force load of the whole structure of the offshore wind turbine, and provides basis for fine coupling dynamic analysis.

Inventors

LIU YINGZHOU
YAN XIANGYU
YAO YE
SHI WEI
LIAN JIJIAN
ZHANG NA
LI XIN

Assignees

天津理工大学

Dates

Publication Date: 20260508
Application Date: 20251230

Claims (9)

1. A method for calculating the refined integral coupling of an offshore wind turbine under the combined action of wind and ice is characterized by comprising the following steps: s1, establishing an offshore wind turbine coupling motion control equation under the combined action of wind and ice load; S2, establishing an offshore wind turbine integral model in FAST, wherein the offshore wind turbine integral model comprises a aeroelastic model of a wind turbine blade and an offshore wind turbine tower-foundation structure model, developing a dynamic ice power module in FAST, and inputting a dynamic ice power time course curve, applying a dynamic ice power load on an offshore wind turbine structure node, and analyzing the response of the offshore wind turbine structure node, including acceleration, speed and displacement, based on the offshore wind turbine coupling motion control equation in S1; s3, building a sea ice-offshore wind turbine three-dimensional refined interaction model in LS-DYNA based on a finite element method-cohesive unit method; s4, setting soil parameters in LS-DYNA based on the sea ice-offshore wind turbine three-dimensional refined interaction model established in S3, and establishing a nonlinear spring-damping theoretical model of a soil layer on the basis of piles to obtain the sea ice-offshore wind turbine three-dimensional refined interaction model considering pile-soil interaction; s5, constructing a sea ice-offshore wind turbine three-dimensional refined interaction model which is based on the S4 and takes the interaction of piles and soil into consideration, constructing a flow field which comprises an air field and a sea water field in LS-DYNA, and coupling the structure of the offshore wind turbine, sea ice, sea water and air to obtain the sea ice-offshore wind turbine three-dimensional refined interaction model which takes the fluid-solid coupling effect into consideration; S6, calculating the dynamic ice force time course under the current time step based on the sea ice-sea fan three-dimensional refined interaction model obtained in the S5, and inputting the dynamic ice force time course into a dynamic ice force module of FAST to obtain the response of a structure node of the sea fan; S7, calculating aerodynamic load and aerodynamic damping of the current time step based on a aeroelastic model of the fan blade in the FAST, inputting the sea ice-offshore wind turbine three-dimensional refined interaction model obtained in the S5, and calculating to obtain dynamic ice force time course, pile foundation node force, node response of the offshore wind turbine tower structure and node response of the offshore wind turbine foundation structure in the current time step; And S8, inputting the dynamic ice force time course obtained by the calculation of S7 into a dynamic ice force module of FAST, circularly executing S6-S7, and performing integral fan structure node dynamic response analysis of all time steps through iteration to obtain a final offshore fan ice excitation dynamic response result and a full-time domain dynamic ice force calculation result.
2. The method for calculating the refined integral coupling of the offshore wind turbine under the combined action of wind and ice according to claim 1, wherein in the step S1, the equation of motion control of the offshore wind turbine under the combined action of wind and ice load is as follows: (1) Wherein [ M ] is a mass matrix of the fan foundation structure, [ C ] is a damping matrix of the fan foundation structure, [ K ] is a rigidity matrix of the fan foundation structure; 、、 Acceleration, speed and displacement vectors of the fan foundation structure nodes respectively; { f ice } is the dynamic ice force load vector, { f elastodyn } and { f G } are the dynamic and gravitational load vectors acting on the fan infrastructure, respectively; to resist the hourglass energy generated by ice crushing when the hourglass energy effect is considered, an hourglass resistance vector needs to be added The motion control equation shown in the formula (1) is converted into: (2) Wherein, the In the event of a wind load, In the case of an ice load, Is an internal force vector; by centre difference solving the formula (2) to obtain: (3) (4) (5) Wherein, the Is the vector of the external force, Is that The acceleration of the moment of time is, Is that The speed of the moment of time, Is that And (5) time displacement.
3. The method for calculating the refined integral coupling of the offshore wind turbine under the combined action of wind and ice according to claim 1, wherein in step S2, the step of establishing the integral model of the offshore wind turbine in FAST comprises the following steps: Setting airfoil aerodynamic parameters of the fan blade, and establishing a aeroelastic model of the fan blade; and establishing an offshore wind turbine tower-foundation structure model based on the geometric parameters of the wind turbine tower-foundation structure.
4. The method for calculating the refined integral coupling of the offshore wind turbine under the combined action of wind and ice according to claim 1, wherein in the step S3, the building of the three-dimensional refined interaction model of the offshore wind turbine and the offshore wind turbine specifically comprises the following steps: preprocessing sea ice parameters, determining an integral coordinate system of a sea ice-offshore wind turbine interaction model and a sea ice local coordinate system, and setting action points of sea ice and a wind turbine foundation structure; establishing a finite element and a cohesive element of the sea ice respectively, and coupling the finite element and the cohesive element to establish a three-dimensional fine interaction model of the sea ice and the offshore wind turbine; And dividing a specific calculation grid for the sea ice and the offshore wind turbine structure, and carrying out grid refinement on the interaction position of the sea ice and the wind turbine foundation structure.
5. The method for calculating the refined integral coupling of the offshore wind turbine under the combined action of wind and ice according to claim 1, wherein in the step S4, the method for constructing the three-dimensional refined interaction model of the offshore wind turbine and the offshore wind turbine by considering the interaction of pile and soil comprises the following steps: And building a nonlinear spring-damping theoretical model of the soil layer on nodes in the x and y directions of the pile foundation by a p-y curve method, wherein the spring damping adopts frequency-independent radiation damping per unit length: (6) in the formula, Damping for the spring; is soil layer density; The shear wave velocity of the soil layer; The diameter of the pile foundation; in order to take into account the dynamic effect of the spring, it is assumed that the dynamic effect of the spring is represented by an amplification factor and a static force: (7) in the formula, Is spring power; is an amplification factor; Is the node at the two ends of the spring absolute value of relative velocity; The dynamic test speed is the initial drifting speed of sea ice; Is static.
6. The method for calculating the three-dimensional fine interaction model of the sea ice-sea fan under the combined action of wind and ice according to claim 1, wherein in the step S5, the method for calculating the three-dimensional fine interaction model of the sea ice-sea fan under the combined action of the wind and the ice comprises the following steps: Based on the S-ALE method, a flow field comprising an air field and a sea water area is constructed, and the coupling interaction of the flow field-sea ice-offshore wind turbine structure is modeled and numerically simulated, wherein a control equation based on the S-ALE method is as follows: (8) in the formula, Is a jacobian matrix; material speed in the i direction; euler coordinates for the i direction; Mass, energy and momentum conservation equations based on the S-ALE fluid-solid coupling method are respectively as follows: (9) (10) (11) in the formula, Is the density of the flow field; material speed in the j direction; euler coordinates in the j direction; And The relative speeds in the i and j directions, respectively; Time is; Is energy; Force per unit volume; is the stress tensor in the j direction.
7. The method for calculating the refined integral coupling of the offshore wind turbine under the combined action of wind and ice according to claim 1, wherein the specific process of the step S7 comprises the following steps: S7.1, setting initial conditions and initial boundary conditions of dynamic response analysis of the integral fan structure in FAST, and reading a wind speed time course file; S7.2, guiding the obtained aerodynamic load and aerodynamic damping of the current time step into the sea ice-offshore wind turbine three-dimensional refined interaction model obtained in the step S5, obtaining dynamic ice force, calculating the node acceleration, displacement and speed of the offshore wind turbine tower structure under the current time step based on the offshore wind turbine coupling motion control equation of the step S1, judging whether the dynamic ice force under the time step reaches the sea ice yield and failure criteria, and calculating the effective stress of a sea ice unit, if the sea ice unit fails, guiding the dynamic ice load under the time step into a dynamic ice force module of the FAST to circulate S6-S7.2, and recalculating the node acceleration, displacement and speed of the offshore wind turbine tower structure; the aerodynamic load and the aerodynamic damping of the current time step are led out to the sea ice-offshore wind turbine three-dimensional refined interaction model obtained in the step S5, pile foundation node force is obtained through calculation, analysis and calculation of the acceleration, displacement and speed of the offshore wind turbine foundation structure node at the next moment are carried out, and the influence of a flow field on the wind turbine foundation structure is analyzed; And S7.3, updating the power response of each part of the whole fan structure at the next moment based on the node acceleration, displacement and speed of the offshore wind turbine tower structure and the node acceleration, displacement and speed of the offshore wind turbine foundation structure.
8. The method for calculating the fine integral coupling of the offshore wind turbine under the combined action of wind and ice as set forth in claim 1, wherein in step S7, the aerodynamic load includes aerodynamic thrust acting on the blades And pneumatic torque load vector The calculation formula is as follows: (12) in the formula, Is an aerodynamic load; Is air density; The number of blades of the fan; is the incoming wind speed; Is an axial induction coefficient; is the inflow angle; is the string length; Is the normal force coefficient; is a tangential force coefficient; Is the tangential induction coefficient; is a circular frequency; Is the relative radius of the blade; Is the phyllin length.
9. The method for calculating the refined integral coupling of the offshore wind turbine under the combined action of wind and ice according to claim 1, wherein in the step S7, the calculation formula of the pneumatic damping is as follows: (13) in the formula, Is pneumatic damping; is rotor thrust; is the wind speed at the height of the hub of the fan.

Description

Marine fan refined integral coupling calculation method under wind-ice combined effect Technical Field The invention belongs to the field of calculation and analysis of offshore wind turbine structures, and relates to a method for fine integral coupling analysis of an offshore wind turbine under the combined action of wind and ice. Background With the strong development of ocean wind energy, the problem of ice vibration of the flexible offshore wind turbine is serious, and the safe operation of the structure and the physical and psychological health of workers are threatened. However, the offshore wind turbine system is a strong coupling system, bears the load actions of aerodynamic force, hydrodynamic force, dynamic ice force and the like, carries out pneumatic-hydrodynamic-elastic coupling modeling on the system structure, and is a basis and important guarantee for researching the dynamic characteristics of the offshore wind turbine system. At present, detailed definition of wind-ice combined action working conditions is lacking in the specifications, the interaction coupling effect among ice load, wind load, pile-soil interaction and structural reaction is complex, and only the influence of individual ice load on the power characteristics of the offshore wind turbine can be well developed in the research at present, and an offshore wind turbine integrated calculation method for wind-water-ice-soil-structural coupling is lacking. Disclosure of Invention In order to solve the problems in ocean engineering, the invention provides a method for calculating the fine integral coupling of an offshore wind turbine under the combined action of wind and ice, which considers the nonlinear structural power, pile-soil interaction, aerodynamic load and pneumatic damping effect, fluid-solid coupling and sea ice breaking failure modes and realizes the integral coupling reaction analysis of the wind-water-ice-soil-wind turbine structure. The technical scheme adopted by the invention is as follows: a method for calculating refined integral coupling of an offshore wind turbine under the combined action of wind and ice comprises the following steps: s1, establishing an offshore wind turbine coupling motion control equation under the combined action of wind and ice load; S2, establishing an offshore wind turbine integral model in FAST, wherein the offshore wind turbine integral model comprises a aeroelastic model of a wind turbine blade and an offshore wind turbine tower-foundation structure model, developing a dynamic ice power module in FAST, and inputting a dynamic ice power time course curve, applying a dynamic ice power load on an offshore wind turbine structure node, and analyzing the response of the offshore wind turbine structure node, including acceleration, speed and displacement, based on the offshore wind turbine coupling motion control equation in S1; S3, building a sea ice-offshore wind turbine three-dimensional refined interaction model in LS-DYNA based on a finite element method-cohesive unit method (FEM-CEM); s4, setting soil parameters in LS-DYNA based on the sea ice-offshore wind turbine three-dimensional refined interaction model established in S3, and establishing a nonlinear spring-damping theoretical model of a soil layer on the basis of piles to obtain the sea ice-offshore wind turbine three-dimensional refined interaction model considering pile-soil interaction; s5, constructing a sea ice-offshore wind turbine three-dimensional refined interaction model which is based on the S4 and takes the interaction of piles and soil into consideration, constructing a flow field which comprises an air field and a sea water field in LS-DYNA, and coupling the structure of the offshore wind turbine, sea ice, sea water and air to obtain the sea ice-offshore wind turbine three-dimensional refined interaction model which takes the fluid-solid coupling effect into consideration; S6, calculating the dynamic ice force time course under the current time step based on the sea ice-sea fan three-dimensional refined interaction model obtained in the S5, and inputting the dynamic ice force time course into a dynamic ice force module of FAST to obtain the response of a structure node of the sea fan; S7, calculating aerodynamic load and aerodynamic damping of the current time step based on a aeroelastic model of the fan blade in the FAST, inputting the sea ice-offshore wind turbine three-dimensional refined interaction model obtained in the S5, and calculating to obtain dynamic ice force time course, pile foundation node force, node response of the offshore wind turbine tower structure and node response of the offshore wind turbine foundation structure in the current time step; S8, inputting the dynamic ice force time course obtained by the calculation of S7 into a dynamic ice force module of FAST, circularly executing S6-S7, and performing integral fan structure node dynamic response analysis of all time steps through iteration t