基于时域方法的风机叶片经典颤振分析OA

With the rapid growth of the installed capacity of wind turbines,the blades are developed to be larger and more flexible,thus more potential structural problems arise inevitably,especially aeroelastic issues such as blade flutter or stall.The flutter problem should be carefully considered during the blade designing process,as it is more critically destructive than general structure vibrations,given the significant economic loss resulting from structural damage to these blades.This paper proposes a time-domain coupled method for blade flutter analysis,which overcomes the reliance on linear assumptions inherent in traditional frequency-domain approaches and thus can be applied to nonlinear complex models.The method integrates modified blade element momentum(BEM)theory with Theodorsen's unsteady aerodynamic forces and computational structural dynamics(CSD),offering a new approach for rapid flutter prediction in engineering applications.It is found that this method can provide an acceptable accuracy at a relatively low computation cost.As an application,the flutter characteristic,by using the developed method,of the NREL 5 MW wind turbine blade is presented and discussed.The results are compared to those in other studies and verified to be reliable.Additionally,we investigate the effects of various assumptions made in various research projects to the results.