Optimization Study And CFD Analysis On Low Wind Speed Wind Turbine Swept Blade

Based on the bionic principle,a curved swept blade technique is adopted to design the blade of low wind speed wind turbine.Based on straight blade,swept blade is designed and optimized by using Isight integrated 3D modeling software and fluid simulation software.Then,the best swept blade is obtained.The straight blade used in this paper is from China&Danmark offshore wind power project.The following is the main work of this paper:1.The wind turbine blade design theory and the wind turbine blade design optimization method are deeply studied in this paper.2.This paper uses Isight optimization platform that integrate 3D modeling software,mesh generation software and fluid simulation software to optimize the swept blade' shape,at the same time,swept area of wind turbine remains unchanged.First,the blade model is parameterized by a self compiled program,and in each optimization process,Isight can invoke the program to modify the model data and ensure that the 3D modeling can be performed.Second,the mesh is automatically divided by ANSYS ICEM-CFD mesh.Finally,the jou script file in Fluent can be used to achieve the automatic setting and numerical calculation of the boundary conditions.The functions of Isight are to integrate and call all software,modify optimization variables,set optimization goals and constraints.Then,the whole 3D simulation optimization of wind turbine blades can be realized.3.The numerical results of straight blade and swept blade in axial inflow condition are analyzed.This paper This paper makes a comparative analysis of three aspects of the blade's outer characteristics(output torque,wind energy utilization factor,thrust force),angle of attack change and section pressure coefficient distribution.The results show that the aerodynamic performance of the swept blade is better than that of the straight blade.Compared with the straight blade,swept blade can increase the output power and improve the coefficient of wind energy utilization at low wind speed.At the same time,swept blade can reduce axial thrust and reduce the thrust peak value on the wind turbine blade surface,which is beneficial to the structural design of the blade.4.The numerical results of the yawing condition of straight blade and swept blade are analyzed.The swept blade can reduce axial load and tangential load on the wind turbine blade surface,and reduce the peak load on the wind turbine blade surface.Compared with the straight blade,the fluctuation range of the load on swept blade in the yaw condition is smaller,and the swept blade wind turbine is more stable at run time.