A two-way coupling method for the study of aeroelastic effects in large wind turbines

• Published in: Renewable energy 2022-05, Vol.190, p.971-992
• Main Authors: Della Posta, Giacomo, Leonardi, Stefano, Bernardini, Matteo
• Format: Article
• Language: English
• Subjects: Actuator line model; Aeroelasticity; CFD-CSD method; Large-eddy simulation; Modal structural dynamics; Wind energy
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2022.03.158

The relevant size of state-of-the-art wind turbines suggests a significant Fluid-Structure Interaction. Given the difficulties to measure the phenomena occurring, researchers advocate high-fidelity numerical models exploiting Computational Fluid and Structural Dynamics. This work presents a novel aeroelastic model for wind turbines combining our Large-Eddy Simulation fluid solver with a modal beam-like structural solver. A loose algorithm couples the Actuator Line Model, which represents the blades in the fluid domain, with the structural model, which represents the flexural and torsional deformations. For the NREL 5 MW wind turbine, we compare the results of three sets of simulations. Firstly, we consider one-way coupled simulations where only the fluid solver provides the structural one with the aerodynamic loads; then, we consider two-way coupled simulations where the structural feedback to the fluid solver is made of the bending deformation velocities only; finally, we add to the feedback the torsional deformation. The comparison suggests that one-way coupled simulations tend to overpredict the power production and the structural oscillations. The flapwise blades vibration induces a significant aerodynamic damping in the structural motion, while the nose-down torsion reduces the mean aerodynamic forces, and hence the power, yet without introducing a marked dynamical effect. [Display omitted] •We propose a two-way coupling method to study aeroelasticity in big wind turbines.•The Actuator Line Model includes blades’ bending deformation velocities and torsion.•One-way coupled simulations overpredict power production and structural vibrations.•The torsion reduces the mean aerodynamic forces, but has limited dynamic influence.•The presence of the tower is key to predicting the fluid and structural dynamics.