风力机叶片动态特性与分形维数关系研究

RESEARCH ON RELATIONSHIP BETWEEN DYNAMIC CHARACTERISTICS OF WIND TURBINE BLADES AND FRACTAL DIMENSION

为探究风力机叶片动态特性与分形维数之间的关系，基于湍流风谱模型Von Karman和NWTCUP生成2种风场，通过多体动力学软件FAST仿真出不同风速条件下的风力机叶片挥舞和摆振时域动态响应，采用计盒维数法求解其分形维数。用发电机输出功率验证分形维数描述风力机叶片动态特性的可行性。结果表明：挥舞时域动态响应的分形维数随风速的增大逐渐减小，而摆振则相反，当达到额定功率时挥舞和摆振的分形维数变化都较小；相同风速下不同湍流风谱模型的功率虽几乎相同，但其对应的分形维数却不同，表明不同的湍流风谱模型有其特定的分形维数。

In order to explore the relationship between dynamic characteristics and the fractal dimension of wind turbine blades, the two kinds of wind field were generated based on Von Karman and NWTCUP turbulent wind spectrum models, the multi-body dynamics software FAST is used to simulate the dynamic response of wind turbine blade flapping and shimmy under different wind speed conditions, and the fractal dimension is solved by the box-counting dimension method. The generator output power was used to verify the feasibility using the fractal dimension to describe the dynamic characteristics of the wind turbine blade. The results show that the fractal dimension of the dynamic response of the waving time domain decreases with the increase of wind speed and the shimmy is opposite, As reaching rating power, the fractal dimension changes of waving and shimmy are smaller; Although the power of different turbulence wind spectrum models under the same wind speed is almost the same, but the corresponding fractal dimension is different, indicating that different turbulence wind spectrum models have their specific fractal dimension.