Influence of meteorological conditions on sound propagation of a wind turbine in complex terrain

Abstract

In this work the influence of different meteorological parameters on the sound propagation of a wind turbine in complex terrain is evaluated based on measurement data assimilated in the Vale de Cobrão (Perdigão, Portugal) throughout the NEWA-Project. Therefore, meteorological data in vicinity of the wind turbine as well as data of three microphones placed in distances of up to 900m from the wind turbine were evaluated. For the two near field microphones a very good correlation between the sound pressure levels and a strong dependency of the actual sound pressure level from the wind speed is found. The correlation between the near field and far field microphones is much less pronounced with a significantly larger variation of the data but still an increase in the sound pressure levels with the wind speed is found. Using data filtering, the measurements were compared for different meteorological situations. It is shown how the sound pressure levels in the far field differ among different meteorological situations for both the A-weighted levels and a single octave band.