Aeroelastic performance analysis of horizontal axis wind turbine (HAWT) swept blades

Abstract Over the past decades, the capacity of commercial wind turbines has risen from 50 kW with 10 to 15 m rotor diameter to 5 MW with more than 120 m rotor diameter. Conversely, increase in the rotor blade length causes substantial blade deflection in torsional, lead-lag and flap-wise directions which leads to unsteady aerodynamic load distributions. The structural safety and stability of the wind turbine will also be affected by the undesirable aerodynamic performance. It is important to analyze the aeroelastic performance of wind turbines under yaw conditions for large scale wind turbine design. Swept blade is a recent innovation to increase the power production of wind turbines while reducing the blade loads. There are insufficient studies in which the effect of yaw error on aeroelastic performance of Horizontal Axis Wind Turbine (HAWT) swept blade has been analysed yet. In this study, aeroelastic performance analysis was performed to investigate the effect of yaw angle on the aeroelastic performance of HAWT with swept blades. The same analysis was performed on HAWT unswept blade, so as to compare the results with that of HAWT swept blade. CFD analysis in ANSYS Fluent was chosen for aerodynamic analysis whereas FEA in ANSYS Static Structural was chosen for structural dynamic analysis. The aeroelastic performance analysis of wind-swept blades under yaw angles of 0°, 10°, 30° and 60° at wind speed of 10 m/s was performed. The results show that yaw error has negative effect on the aeroelastic performance of swept blade as well as unswept blade. It can be proven that swept blades have a better aeroelastic performance in terms of higher rotor power and lower deformation than unswept blades, i.e. higher stability of swept blades under yaw condition compared to unswept blades.