基于脉冲激励响应的风力机叶片结构阻尼计算

针对大型风力机叶片气弹振动问题,提出一种基于脉冲响应的大型风力机柔性叶片结构阻尼有效分析方法.采用一种5自由度的超级单元,将柔性叶片离散成由若干超级单元构成的多体系统,基于计算多体系统动力学中的R-W方法建立了叶片的动力响应模型.以美国可再生能源实验室(NREL)发布的5 MW近海风力机叶片为研究对象,通过分析叶片在脉冲激励下的动力学响应得到其传递函数,由半功率带宽法计算叶片在静止和运转工况下的挥舞与摆振结构阻尼,从而为确定叶片气弹稳定性的边界提供依据.该研究对于指导叶片结构与气动外形设计、帮助确定其气弹稳定性边界具有重要意义.

Structural damping calculation of wind turbine blade based on pulse excitation response

In order to solve the aeroelastic vibration problem of large wind turbine blade, an effective analytical method for the structural damping of flexible blade of large wind turbine based on pulse response was proposed. A kind of super units with 5 degrees of freedom(DOFs)was used to discretize the flexible blade into a multi-body system(MBS)which consists of several super units, and the dynamic response model for the blade was established based on the R-W method in computing the multi-body system dynamics. The 5MW offshore wind turbine blade issued by the United States Renewable Energy Laboratory(NREL)was chosen as the research subject, and the transfer function of blade was obtained by analyzing the dynamic response of blade under the action of pulse excitation. In addition, the structural damping of blade in both flapwise and edgewise modes under the static and rotating conditions was calculated by the half-power bandwidth method in order to provide a foundation for confirming the boundary of aeroelastic stability of blade. The present study is of important significance for the design of blade structure and aerodynamic shape, and helpful for the confirmation of aeroelastic stability boundary of blade.