Vibration Attenuation of Rotating Blades Using a Non-Linear Energy Sink

Wall, Ira P.; Amoozgar, Mohammadreza; Popov, Atanas

Abstract

The global climate crisis is placing higher demands on the performance of wind turbines. One of the promising methods to enhance the wind turbine performance is to increase the rotor diameter by having larger blades. However, the blade length is always constrained by its fatigue life due to vibratory loads or aeroelastic instabilities. To overcome this limitation, in this study a Nonlinear Energy Sink (NES) device is proposed to be integrated inside the blade to reduce the plunge and twist vibrations of the blade. NES devices are ineffective until an energy threshold of the primary system is exceeded at which point, they become highly effective at damping nonlinear structures. In this paper, this energy threshold correlates to the onset of flutter instability. One of the limitations of using a passive NES is that it could enhance the vibration of the system considerably in regions prior to flutter occurring if it is optimised for unstable damping. For this reason, this paper proposes the usage of a tuneable NES as an active vibration absorber that is capable of tuning to the optimum parameters of a given wind condition. A genetic algorithm has been used to demonstrate the effectiveness of tuning the NES to the optimum conditions for each flow speed. The Tuned NES (TNES) is shown to have an average amplitude reduction of about 19% across the range of flow speeds compared to 9% for the passive design with fixed optimum parameters.

• Conference Name: AIAA AVIATION 2023 Forum
• Conference Location: San Diego, CA and Online
• Start Date: Jun 12, 2023
• End Date: Jun 16, 2023
• Acceptance Date: Jun 8, 2023
• Online Publication Date: Jun 8, 2023
• Publication Date: Jun 12, 2023
• Deposit Date: May 18, 2024
• Publisher: American Institute of Aeronautics and Astronautics
• Book Title: AIAA 2023-3952 Session: Applied Aeroelasticity and Aerodynamic-Structural Dynamics Interaction II
• DOI: https://doi.org/10.2514/6.2023-3952
• Public URL: https://nottingham-repository.worktribe.com/output/22154838
• Publisher URL: https://arc.aiaa.org/doi/10.2514/6.2023-3952