| dc.description.abstract | Wind turbine blades are growing progressively larger and lighter relative to their size, and these trends can lead to early failure due to fatigue. Effort to design fatigue-resistant blades relies on understanding of aeroelasticity—the study of unsteady interaction of structural, inertial, aerodynamic phenomenon.
The goal of this work is to provide needed wind tunnel experiments targeted at aeroelastic phenomenon relevant to wind turbine blades. The design of a wind tunnel test platform consisting of a rigid, cantilevered blade mounted to an elastic base, capable of flap and twist motion, is presented. The parameters of this model blade are intended to match the dynamic aeroelastic response of a reference design for a large-scale, megawatt-class wind turbine blade. A time-domain predictive model, based on 3D unsteady aerodynamics, is presented to simulate the aeroelastic response of the test platform subjected to arbitrary aerodynamic disturbances. Experimental validation of the predictive model is presented, and comparisons between different aerodynamics models are performed to identify regions of validity. From the experiments and model, conditions of interest to the study of fatigue are identified.
Experimental responses to periodic disturbances with a reduced frequency ranging from 0.098 to 0.56 are measured and compared to simulations. The simulated spanwise lift distribution agrees well with the measurements over the entire frequency range. The simulated flapwise deflection angles agree well with measurements when reduced frequency is less than 0.25. This simulation model, and the accompanying test article, will serve as a platform for future research into wind turbine aeroelasticity and active control. | en |
