Prediction of atmospheric sound propagation subject to parameter variability of atmospheric turbulence

As part of the project ""WEA-Akzeptanz""an atmospheric sound propagation model is developed to predict the sound immission from a wind turbine. The CNPE (Crank Nicolson Parabolic Equation) method, based on the Helmholz equation is chosen as the sound propagation model. Complex environmental conditions such as atmospheric turbulence can be implemented with a random number generator in this model. Atmospheric turbulence is characterized by temporal fluctuating wind speed and temperature, which has an impact on the sound propagation and leads to scattered sound waves due to the turbulent eddies. Accordingly, the input of the model contains parameter variability. As a result, the sound pressure level at the point of immission also has a high variability and is not entirely deterministic. In this work, the influence of random input variables due to atmospheric turbulence on the uncertainty of the resulting sound pressure level is investigated. Using this, the probability of the predicted sound pressure level can be quantified to get a better idea of sound immission under complex atmospheric conditions.