Wind turbine rotor aerodynamics

Abstract

Wind turbines are operating under very complex and uncontrolled environmental conditions, including atmospheric turbulence, atmospheric boundary layer effects, directional and spatial variations in wind shear, etc. Over the past decades, the size of a commercial wind turbine has increased considerably. All the complex and uncontrolled conditions mentioned above result in uncertainties of aerodynamic loads calculation on very large wind turbine blades and thus better numerical codes are needed for predicting the loads in the design phase. With the aim to eliminate these uncontrolled effects and improve the aerodynamic models, in last decades, several important experimental campaigns of different wind turbine models have been performed in large wind tunnels. The objective of such experiments (e.g. using the NREL wind turbine and the MEXICO rotor) is to provide high quality measurement data which can be used to validate numerical models and improve different fidelity numerical codes, particularly for predicting wind turbine aerodynamic loads.