Wind energy utilization characteristics of blades under operation of wind turbines with fixed pitches and variable pitches

Based on the momentum-blade element theory,the geometric shape and operating conditions of the wind turbine blades were designed,and the finite element model for wind turbine blades was established.The model was then used for numerical study of the aerodynamic characteristics of the blade.It was shown that with large angle of attack and low rotating speed,the blade tip loss has a more evident impact on the blade power and efficiency;under variable conditions,the blade power and efficiency curves are generally in accordance with the law of the airfoil and blade aerodynamic characteristics,and the curve slope is influenced by the blade lift-drag ratio and stall effect,and the tip loss.