Aerodynamic Loads On Rotor Blades

Abstract: In the last decade, we have heard more and more about the need of renewableclean energy, but not much has been done. Currently, the wind powerenergy is the most popular of all of these green technologies. Thousands ofwind turbines are being invested and installed everywhere worldwide. Thus,many questions arise.The aerodynamic loads on the rotor blades are the largest loads acting ona wind turbine. The horizontal wind turbine types of blades are usually madeof two or three airfoils such as a propeller. In these types of blades, it is thelift force which makes the rotor turn. The drag force acts perpendicular tothe lift force due to the resistance of the airfoil from the wind and counteractsthe rotation to rotor. Therefore, predicting these loads accurately is one ofthe most important parts of the calculations in wind turbine aerodynamics.Another reason for computing the aerodynamic loads on rotor blades is tomodel the aeroelastic response of the entire wind turbine construction. Thereare different methods to calculate the aerodynamic loads on a wind turbinerotor with different level of complexity such as Blade Element MomentumMethod (BEM), Vortex Method, Panel Method and Computational FluidDynamics (CFD). Most aerodynamic codes use BEM (together with manyadditions) which is very fast and gives fairly accurate results.The main goal of this project is studying the Helical Vortex Method.In this text, helical vortex method has been developed and compared withBlade-Element Momentum (BEM) theory for the analysis of wind turbineaerodynamics.