Analysis Of Aerodynamic Characteristics Of Swept-back Wind Turbine Based On Co-simulation

Wind turbine is a complex system with mechanical,fluid and control coupling.It is very important to establish an accurate dynamic model of wind turbine at the beginning of design to simulate the performance of wind turbine in normal operation.Swept blade is a kind of wind turbine blade with the overlapping line bending towards the trailing edge of blade.Compared with straight blade,swept blade can achieve lower load and higher wind energy utilization rate,but this kind of blade has prominent bending-torsion coupling in structure,and the three-dimensional flow phenomenon is obvious.This thesis uses the advantages of modeling software of different disciplines to establish the structural model and aerodynamic model respectively,and completes the construction of aerodynamic coupling analysis model of wind turbine through co-simulation.The aerodynamic coupling effect of wind turbine in operating environment is simulated accurately.The research work provides simulation data support for the design of safe,reliable and efficient power generation of the swept-back wind turbine and the maintenance of stable and efficient operation of the turbine,which has important engineering application value.The main research contents of this thesis are as follows:（1）The 10 MW wind turbine is taken as the research object.Through the multi-body dynamics analysis software to build wind turbines-soft coupling multibody dynamics model of the "super element method",will be swept blades,tower,main shaft and after grazing type wind turbine engine discrete dynamics system,and the swept-back blade and swept-back type wind turbine machine of eigenvalue analysis,validate this article build wind turbines effectiveness and accuracy of the multi-body model,On this basis,the structure modules of blade and swept-back wind turbine are built.（2）Based on the lift line theory,the aerodynamic load calculation model suitable for swept blade was established in MATLAB.The model has good three-dimensional flow field analysis ability,and can accurately simulate the structural nonlinearity and the bending-torsion coupling characteristics of swept blade,and carry out aerodynamic and elastic coupling analysis and calculation.The aerodynamic load calculation model of swept blade is integrated and the co-simulation aerodynamic model is established in Simulink platform.（3）Due to the large structure,complex composition and many degrees of freedom of the whole wind turbine model,it will be difficult to use the lift line theory based on eddy current theory to conduct air-elastic coupling analysis.Therefore,the relative coordinate system motion equation theory and complete recursive algorithm of multi-body dynamics analysis software and rich powerful,with a variety of efficient solver Simulink software co-simulation.Multi-body dynamics analysis software and Simulink co-simulation technology are used to realize synchronous control and coupling calculation of structural model and aerodynamic load model.（4）The co-simulation model was used to simulate and calculate the dynamic responses of large scale swept-back wind turbine under wind speed of 5-25 m /s,random wind speed and gust,analyzed the power characteristics and elastic response characteristics of windswept wind turbine,and studied the structural deformation,motion characteristics and the influence of parameters of windswept wind turbine during operation.In this thesis,the simulation analysis model of large-scale swept-back wind turbine is established by means of co-simulation,which not only improves the modeling speed of large-scale and large deformation complex structure model,but also achieves better analysis and calculation accuracy.At the same time,the work of this paper provides an effective numerical calculation method and analysis approach for optimal design of large wind turbines and dynamic response analysis under complex wind conditions.