Study On The Dynamic Characteristics Of Blade Of The Wind Turbine

With the development of society and the progress of science and technology, the mankind faces the serious exhausted challenge with the problem of being deficient of resource and environmental pollution day by day. At this moment wind energy is remarked as a sort of new energy that is large in reserves, wide in distribution, the cheapest, the most clean and the most valuable to exploit. So it has received the extensive attention from all walks of life, the research to the wind turbine intensifies gradually too. In our country, the efficiency of the use of the wind turbine is comparably subjacent. So in order to handle it well we must accelerate the research of them.Blade, the force on which is the most complicate and the design on which is the most awkward, is an important component of the wind turbine, the blade is under aerodynamic force, mass force and elastic force, the amplitude of which is increasing on and on. Such unstable vibration, will cause very great stress of moving in the structure, influence the normal running of the wind turbine, will even cause the serious consequence that the part and complete machine are damaged. Then, the research of the aerodynamic and elastic character of the wind turbine, become the important problem, which is relation to the safety and reliability of the wind turbine, and also become the focus in development of the wind turbine.In this paper based on the aerodynamic theory, and by setting up the equation of dynamics . blade buffeting question were discussed under the function of the up-down force or twist aerodynamic force by dynamic equation and the formula, then it can be founded: pure up-down vibration basically is aerodynamic damping motivation and the pure aerodynamic twisl vibration is also aerodynamic damping motivation to some extent, therefore, the possibility that the single-degree-of-freedom buffeting happened is limited. Under the function of the up-down force and twist aerodynamic force the radiation vibration will happen on the wind turbine. The blade buffeting question were discussed under the function of the up-down force and twisl aerodynamic force, the effective factor to the buffeting marginal speed is also analyzed. Basedon model analysis, the natural frequency and the vibration shape are gotten by the means of finite element. The calculating results show that the first three mode of blade under the lower grade frequency are all integral sheer bending vibration. Enlarging the fourth and the fifth model shape figure, the slight twisted vibration was observed on the tip of the blade. Considering the integration order and the effect of constraint condition to the model shape, comparing model shape with experimental data, the analysis about theory is right.