Aerodynamic Performance And Vibration Characteristics Study For Horizontal Axis Wind Turbine Blade

The blades are one of the most important components of the wind turbine，and itsperformance has important influence to the wind turbine．The untwisted blade is generally used for the small wind turbine，and the twistedblade is used for the large wind turbine．The less untwisted and twisted bladeaerodynamic performance research and their comparison of small wind turbinebecome necessary study content．Due to high quality and excessive cost, thegeometrical optimization for the blade airfoil of large wind turbine blade has becomeimportant research topic. The large wind turbine is tall large-scale in structure, thevibration characteristics of its blade is essential for structural safety. In this paper, theblade aerodynamic performance is researched by computational fluid dynamics (CFD)method, and the modal analysis of blade is done. The main content is listed asfollows：(1) The untwisted and twisted blade of small wind turbine and twisted blade oflarge wind turbine is designed firstly by Wilson optimization design model. Then,their geometry model is established by software Pro/E. The fluid computational modelmesh is established by software ICEM; The aerodynamic performance and modalcharacteristic of the blade is studied by CFX and ANSYS．(2) Changing the pitch angle can improve untwisted blade aerodynamicperformance greatly. The blade running at the appropriate tip speed ratio can capture more wind energy. The blade with initial airfoil of large wind turbine has the bestaerodynamic performance，but it is relatively expensive. With the slight increase ofblade thickness for large wind turbine, the aerodynamic performance decreased lessbut its cost reduced largely. When the blade relative thickness increase largely, theblade aerodynamic performance decline dramatically and its cost reduce rapidly.(3) The initial blade, thicker blade and thickest blade of the large wind turbinecan all avoid the vibration excitation frequency on running at the optimum tip speedradio. Three blades at low-level vibration shapes are waving and swinging and theshapes coupling also can be ignored, three blades at high-level vibration shapes aretwisting．By comparison of three blades10-order vibration shape, the initial blade hasthe best vibration characteristics, the thicker blade has the better vibrationcharacteristics，the thickest blade has the worst vibration characteristics．...