University of Trieste has collaborated with Valorem via secondments in order to achieve in relation to noise pollution associated with wind turbines.
During this period they highlighted the realistic problem related to wind turbine and wind farms, in term of noise pollution.
Their research identified the primary areas of interest within this field as the acoustic characterization of a single wind turbine under different conditions, and the propagation model for complex noise sources in realistic environments.
In particular, with regard to the acoustic characterization of a single wind turbine we want to include the effects of wind turbine immersed in an atmospheric boundary layer, the acoustic signature of a downwind wind turbine, the influence of turbine geometry, and the interaction between mechanical properties of wind turbine and areodynamic fluid flow (Fluid Structure Interaction).
In parallel, the objective of the propagation modeling is to propagate these complex noise sources in order to achieve an accurate representation of noise related to realistic wind farms.
As a preliminary step, a comparison was conducted between the noise identified through numerical simulation of a single wind turbine and the technical specifications of a similar, realistic wind turbine.
The numerical simulation employs a high-fidelity approach to characterize the aerodynamic turbulent flow around a single wind turbine, utilizing the Large Eddy Simulation (LES) method. Ultimately, the Computational Aero Acoustics (CAA) method, founded upon the acoustic analogy, enables the measurement of the noise generated by the wind turbine at the same point as the technical specification.
The initial comparison, illustrated in Figure 1, demonstrates a satisfactory correlation between our computations and the technical specifications with regard to the noise spectrum (1/3 octave band) with A-attenuation decibels (dBA). This enables us to evaluate the efficacy of our numerical simulations.
Further developments will entail the consideration of the geometry of a realistic wind turbine and the extension of the database in order to achieve a spectrum with a range of frequencies from 1 Hz to 10 000 Hz. This approach allows us to evaluate the efficacy of our numerical method and to obtain a precise characterization of the acoustic signature of a wind turbine.
