Optimization Design And Numerical Simulation Analysis Of Mw Grade Direct Driven Wind Turbine Blade

With the rapid development of economy and the increasing of people’s living standard, the demand for energy is growing quickly, but the serious problems of environment are caused at the same time. In the face of energy shortage, environment pollution and so on, every country has to begin to exploit and use clean, renewable energy. As wind power has the advantages of clean,non-polluting, renewable and others, it gets great support from lots of countries.On the other hand, resource of wind power is huge, and in the process of using will not cause any air pollution. Wind generator is the main way of using wind power. Blade is one of the core parts of wind generator and its design quality will directly affect the power generation efficiency, safety and life of wind generator. Especially, in recent years the increasing demand for high power wind turbine, its quality will directly affect the economic benefits of wind power industry. Therefore, it is very necessary to do research on the design and aerodynamic performance analysis of MW grade wind turbine blade.Based on 1.5MW direct drive wind turbine blade as the object of research,This paper has carried out the aerodynamic shape optimization design of wind turbine blade, the rotor aerodynamic performance calculation and the analysis of the numerical simulation of wind field. In order to study the aerodynamic anddynamic characteristic of wind turbine blade that is designed in this paper. The main research contents are as follows:First of all, based on the aerodynamic basic theory of wind turbine blade design and methods of rotor aerodynamic performance calculation, and combined with particle swarm optimization algorithm based on simulated annealing, the design optimization model of the aerodynamic shape of blade is established. The calculation programs are written, including of wind turbine blade optimization design and the correction processing calculation program of blade chord length and torsion Angle, at last, wind turbine blade is gained, it not only meets the actual manufacturing requirements, but also has the largest wind energy utilization coefficient.Secondly, based on the theory of momentum-airfoil, the designed wind turbine blade has been carried out the rotor aerodynamic performance calculation, and according to the calculation results, it proves that the result of design is consistent with the design requirements. Then according to the revised shape parameters of blade and the section airfoil, and combined with airfoil coordinates transformation theory, the three-dimensional solid model of wind turbine blade is established by MATLAB and Pro/E software.Finally, given the aerodynamic characteristics of wind turbine blade and the flow status of blade surrounding flow field, the numerical simulation analysis of rotor has been carried out, including the air flow conditions of different section along the direction of blade, the pressure distribution of different section and the blade pressure of different flow speed under the rated conditions, and on the basis of analysis of the flow field, the paper exploits the effect on dynamic characteristic, resulting from the fluid-structure coupling and pre-stressing. Through the analysis of the velocity and pressure of blade different cross-section and the pressure nephogram of different flow speed, it is concluded that the situation of flow field around the rotor and the surfacepressure condition of blade, these dates provides basis for the further design of blade. Through turbine torque from the analysis of flow field, the output power of wind turbine and power utilization coefficient is calculated, comparing with the results based on the theory of momentum and airfoil. It proved the correctness of the theoretical calculation results, and the effectiveness of the blade design once again. By analyzing the stress and deformation under the fluid structure coupling and the vibration situation of wind turbine under the action of pre-stress, the designed blade can operate properly without the phenomenon of resonance.