Within the project an interdisciplinary approach is adopted, which links physical sound generation and radiation with the psychoacoustic assesment at the place of immission.
With the collaboration of the industry partner Senvion and several institutes of the Leibniz University Hannover an overall acoustic model is developed. The model includes sound generation on the rotor, on wind turbine components and on the nacelle, as well as sound propagation to the recipient under realistic atmospheric conditions. The overall model also considers the psychoacoustic annoyance assessment of the calculated sound immissions, which is particularly important for public acceptance.
To validate the submodels and the overall model, extensive field tests are carried out under different environmental conditions. The influence of different operating conditions and appropriate measures for sound reduction are evaluated. In future, with the validated model, it will possible to obtain a psychoacoustic assesment and an acoustic simulation of the wind turbine at an early stage in the planning phase, taking into account the predicted sound emissions, sound propagation and sound preception.
The joint project pursues several subgoals:
Sound generation and sound reduction - Partner Senvion
• Development of a validated model for aerodynamic sound which includes add-on components, effects of aging, special operating states and wind farm effects.
• Development of a model for structural dynamics and sound radiation, as well as the excitation and transmission of structure-borne sound by wind turbine-specific components.
Sound propagation - Partner Leibniz University of Hannover (Institute of Structural Dynamics and Institute of Meteorology and Climatology)
• Development of a meteorological model for the determination of important atmospheric parameters for sound propagation.
• Development of a sound propagation model that accurately maps atmospheric conditions and the influence of topography.
Sound perceptions - Partner Leibniz University of Hannover (Institute of communications technology)
• Creation of a 3D audiovisual simulation environment for the psychoaccoustic evaluation of wind turbine operating sound at the placeof immission, including simulations of different radiation, weather and wind turbine operating conditions, also for comparative acceptance studies in the planning phase.
• Assesment of the wind turbine immission regarding annoyance in different domestic working and living situations.
• Psychoacoustic modeling of the loudness and annoyance of wind turbines at the immission site in order to specify validated and more realistic loudness and annoyance measurement methods for objective measurements as well as for the optimization of sound design with regard to minimum annoyance.
Complete model - All partner
• Coupling of the individual submodels to the overall acoustic model.
• Superimposition of the aeroacoustic frequency spectrum with the sturcture-borne sound tones to identify possible tonalities in the design phase.
• Development, design and presentation of measures for cost-effective reduction of sound generation, sound transmission and sound radiation, as well as adaption of the sound spectrum to psychoacoustic specifications (sound design).
• Definition of relevant meteorological situations for operational interventions.
