Aeroelastic investigation and stability of small- and mid-scale wind turbine blades

An enhanced reduced-order model is proposed to analyze the stability of small- and mid-scale wind turbine blades. A series of linear and nonlinear analyses are presented conjointly to assess the effects of various design parameters on the blade’s stability, namely, the blade length, the manufacturing material, the additive manufacturing aspect, and the blade’s scaling approach among others. The effect of different nonlinearities, mainly geometric and inertial, on the aeroelastic system’s response is also explored for different stall coefficient scenarios. Furthermore, a more accurate determination of the stall characteristics from the lift curve data of various symmetric and nonsymmetric airfoils is discussed in details along with its incorporation in the suggested blade reduced-order model for an accurate and robust modeling that shall accurately portray different intricate fluid–structure interaction aspects between the blade and its surrounding flow. Additionally, the moments of inertia of the modeled blade are obtained via an exact airfoil cross-section solution and are compared to the rectangular approximation conventionally used in the literature. The results show the large impact of the blade’s material selection and the additively manufactured cross-section types on the stability of the blade, and therefore highlight the importance of conducting aeroelastic and stability analyses with accurate nonlinear reduced-order models even for smaller-scale turbine blades.