Noise emission during construction and operation of wind power plants investigated by numerical methods

The noise emission during construction and operation of wind power plants is an issue which gained of considerable importance in recent years. Therefore, not only experimental investigations but also calculations need to be performed in order to acoustically enhance the wind turbines and their installation. Due to the large size and the high complexity of the systems, however, the use of simulation methods is only possible, if the calculation models are distinguished by a particularly high numerical efficiency. In the current paper, it is shown which calculation methods are recommended and which accuracy can be expected when they are used to predict the sound emission. Two representative examples of significant practical relevance are discussed in detail: The prognosis of underwater construction noise when setting up offshore wind turbines and the acoustic emission of a complete onshore wind turbine during operation. For the investigations a variety of numerical methods is used, namely analytical formulae, the Finite Element Method (FEM), the Boundary Element Method (BEM), and the Finite Volume Method (FVM).