Vibration Analysis And Optimal Design Of Large-scare Wind Turbine Blade

The study of aerodynamic performance of wind turbine blades has the majorsignificance for the design of wind turbine blades. For the model of1.5MW wind turbineit is established by applying the first three-dimensional modeling software. Under the fanrated conditions, the blades of dynamic characteristics and modal are analyzed theseventh-order vibration and natural frequency are also solved, which provides a referencefor the actual design and manufacture of wind turbine blades.In order to obtain the comparing results of the lift coefficient and drag coefficientunder the condition of airfoil and icing airfoil, with the way of CFD calculations, thesimulation of aerodynamic performance is given. From the results, it is obtained that thelift coefficient is greatly impacted by icing airfoil; however, the drag coefficient has thelimited impact. When the values of Reynolds number are different, there is also has limitedimpact on the lift coefficients and drag coefficients. Convection field is greatly affected byicing airfoil, which leads to pressure mutations and wake vortex occurring in advance. Thekey reason for the phenomenon is the asymmetric of the flow field. Through this study, atheoretical reference and the analysis of new ideas are provided for blade designers.Secondly, this paper presents fault recognition method of wind turbine blade based onfuzzy neural network. This method carries out fault diagnosis according to vibrationspectrum diagram in each frequency band range of the wind turbine blade. Experimentalresults show that the method can recognize various faults of wind turbine blade such as icy,crack, wear and tear effectively, which has an accuracy rate above90%.Finally, a model for optimization design of wind turbine blades is presented. Thismodel bases on momentum-leaf pigment theory. Considering the aerodynamic forces ofwind turbine blades, optimization search is carried out by using of genetic algorithm with agoal of the annual energy output in every section of the wind turbine blades. The bestchord length and torsion angle of specific section wind field is designed by using thedeveloped program of the optimum design, Simulation results show that, with theoptimization of improved genetic algorithm, aerodynamic performance of wind turbine blade can be obviously i mproved.