Flutter-suppressing Analysis Of Perforated Damping Structural Blade For Large Wind Turbine

Wind energy,as a renewable green energy,has developed rapidly with the increasing prominent energy security issues in the global context,and keep moving towards the direction of single high-power.As the most basic and key component of the wind turbine,the blade is becoming more and more flexible.The coupled vibration between modes of the blade is more likely to happen and becomes more prominent with the development of the blade under the coupling effect of aerodynamic force,elastic force and inertial force.The alternating stress induced by the flutter of the blade can cause the fatigue crack of the blade and even breakage.Therefore,the suppression of long-type blade flutter has become a new topic on the research of large-scale wind turbine.As for the flutter problem of the long-type blade,the main contents of this paper are as follows:1.The status quo of the development of wind power industry at home and abroad and the research progress of modern wind turbines were studied.The problems of flutter and the research of vibration suppression technology in the process of large-scale wind turbine development were pointed out.2.Co-curing perforated damping blade was proposed in the consideration of structural damping and stiffness,and the structural loss factor,the stiffness parameter and the shear parameter were derived based on the constrained damping structure theory.The influence of the perforation parameters on the structural performance of the blade was discussed in detail.3.The structural stability and the flutter-suppressing abilities of the perforated damping structural model were studied by establishing the bending-torsion coupling vibration model and the airfoil micro-unit deformation model.The mechanism of the aeroelastic flutter of the perforated damping structural blade was also discussed.4.According to the relevant parameters of a 1500 kW wind turbine blade,the finite element models of turbine blades with undamped,damped and perforated damping combined with the equivalent mass method and modal peak analysis method were respectively established in ANSYS software to simulate flutter-suppressing abilities and structural properties.The contact pairs between the interfaces of the co-curing damping blade and the co-curing perforated damping blade were created with MPC algorithm.5.Based on the finite element model of the three kinds of blade,the modal analysis and the transient dynamic analysis of the three types of blade were carried out respectively.The dynamic wind load was simulated based on the two-parameter Weibull distribution function.On the basis of the large deformation analysis theory and by setting multi-load steps and two parameters of Rayleigh damping,the transient dynamic response analysis was accomplished under the action of gravity load,centrifugal force load and aerodynamic load combined with the Newmark time integration algorithm.The comparison results show that the perforated damping structure blade has both higher structural damping and better structural stiffness,and can also effectively suppress the vibration strength and vibration speed of the blade during the run.Consequently,the operation stability of the blade is improved effectively.