These slides were presented at the NAFEMS World Congress 2025, held in Salzburg, Austria from May 19–22, 2025.

Abstract

Renewable energy, particularly wind power, has become one of the fastest-growing and most affordable energy sources globally. To meet climate goals, expanding wind energy infrastructure requires extensive land use, which has driven more stringent regulatory standards to manage environmental and noise impacts. As wind turbines proliferate, concerns over their acoustic footprint, especially in densely populated and environmentally sensitive areas, have intensified, both aero-acoustic and vibro-acoustic modeling becomes essential to predict and mitigate wind turbine noise. This study introduces a multi-fidelity framework for aero-acoustic simulation of wind turbines. The framework combines semi-analytical aerodynamic/aero-acoustic calculations with detailed Computational Fluid Dynamics (CFD) simulations, leveraging both two-dimensional blade profile analysis and full three-dimensional turbine models. The framework is initially validated using full-scale field test data, which serves as a baseline for testing methodology accuracy and reliability. The focus then shifts to assessing noise mitigation potential through the analysis and optimization of serrated trailing edges on wind turbine blades. By analyzing blade sections in both quasi-two-dimensional wind tunnel and full three-dimensional conditions, it is found that serrated trailing edges effectively reduce airfoil trailing-edge noise. As aero-acoustic levels decrease significantly through advanced simulation methods, previously masked tonal noise issues emerge as prominent challenges. These distinct, narrow-band sounds are particularly intrusive and can disrupt nearby communities, prompting stricter regulations to protect public health and environmental quality. A common source of tonal noise is transmission error from gear meshing within the drivetrain, generating vibrations that travel along load-dependent paths to radiating surfaces'”typically the tower'”before propagating through the air to microphones at ground level. This study introduces a high-fidelity, multi-disciplinary simulation workflow to enhance understanding and mitigation of these vibro-acoustic challenges. Given the complexity of wind turbine noise management, the collaboration between original equipment manufacturers (OEMs) and suppliers is crucial. This multi-disciplinary approach to system modeling, with new functionalities enabling the integration of IP-protected subsystems, facilitates a holistic approach to noise reduction while maintaining proprietary technology protections. In conclusion, the proposed multi-fidelity framework offers a robust tool for predicting and mitigating wind turbine noise. By combining aerodynamic, aero-acoustic, multibody and vibro-acoustic simulations, this approach addresses both broadband and tonal noise issues, providing a pathway toward quieter, more environmentally compatible wind turbine designs.