Evaluation of Wind Turbine Noise based on Numerical Simulation Methods

Abstract

The objective of this paper is to propose a more general, largely non-empirical prediction method for sound spectra and directivity functions based on high fidelity 2D computations. In its current state the approach concentrates on turbulent boundary-layer trailing-edge noise (TBL-TEN) but could be later expanded to include also leading-edge / inflow interaction- and TBL separation noise. In the current work an aeroacoustic data base is set up consisting of pre-computed aeroacoustic results of independent computations for different airfoils, different representative angles of attack, and different flow conditions. Making use of these data, the authors estimate the sound emission of single blade elements. The suggested method allows for a representation of all operational conditions along the acoustically relevant part of the outer rotor blade. The method is verified at certain test conditions. It is applied to angles of attack and blended airfoil geometries not originally included in the data base.