Multi-objective Optimization Design And Structure Dynamics Analysis Of Horizontal Axis Wind Turbine Blade

This paper belongs to National Key Technologies R&D Program -------- Aerodynamic optimization design and structure dynamic analysis of wind turbines blade. To meet the requirements of the aerodynamics, structure and stability, multi-objective optimization methods of HAWT blades have been developed. Through optimizating the shape parameters in the different distance from blade root, such as, relative thicknesses, chord lengths and torsion angles of the airfoils, the aerodynamic design optimization results that a power utilization factor Cp reached the intended target could be got. Finally, considering some requirements of structure and manufacturing process, aerodynamic shape was revised. After optimizing HAWT blades, load calculations were carried through to decrease the loads of the root. And on the basis of loads calculation, there was strength analysis on HAWT blades. The main contents were as follows:The design objective was to find blade shape such that maximizing power utilization factor as well as decreasing the loads. Considering aerodynamic performance and loads, multi-objective optimization of the blade was carried to take care of the stability and structure strength indicators, in addition to ensure a good performance of wind-turbine rotor blade,. Blade optimization design was that relative thicknesses, chord lengths and torsion angles in different sections, were regarded as design variables, and a multi-objective optimization mathematical model was established. Based on the genetic algorithms with the use of MATLAB software, a multi-objective optimization blade design was achieved. At the same time, this method was used to optimize and design a 1.5 MW wind turbine blade. Compared with some commercial blade model, the effectiveness of the method had been verified.GAMBIT, the pre-processing module of FLUENT software, was used to establish a 3D model of the blade, and the wind-turbine rotor blade model was completed into ANSYS software to modal analysis. In view of the characteristics of fiber reinforces plastic, a mesh was built to carry out the model analysis, and the first 10 orders of the vibration frequencies and mode shapes were obtained, by imposing certain bound on the root of blade. Meanwhile, the impact of Coriolis on Modal Analysis of the blade was researched. Based on GL coordinates, aerodynamics, gravity and centrifugal force on the wind turbine were calculated. With the help of Bladed for Windows software, a 1.5 MW horizontal axis wind turbine blade was taken for example to calculate the loads of the root, and the maximum load of the root were identified. The finite element analysis was done in ANSYS software, and the deformation and stress cloud figures under limit load were got. After determining the safety coefficient, the static strength check was completed.According to IEC61400-1 standard, the various working conditions of 1.5 MW horizontal axis wind turbine were studied and the loads under various conditions were calculated, the maximum load and the corresponding condition were extracted from the post-processing modules in Bladed for Windows software, with which the strength of wind turbine blade cloud be checked.