Trailing-edge noise can be the dominant noise source of diverse industrial applications, including wind turbines. Noise regulations may limit the power production and installation of new wind farms. There is a need to reduce it. In order to achieve so, we first need to predict it, and to do so we need experimental data to support and validate the new methodologies. A new experimental campaign has been carried out to provide a benchmark of trailing-edge noise applicable to wind turbine noise. It involves a broad range of Reynolds numbers and angles of attack, and covers the noise reduction effect of serrations. This Thesis studies the aforementioned novel data set. The trends of the far-field noise with the forcing of the boundary layer, angle
of attack, and Reynolds number have been studied. Furthermore, scaling laws have been applied to compare different test conditions. The collapse quality has been studied, and the differences have been linked to the aerodynamics and possible post-processing effects. The effect of the serrations has also been studied. Additionally, the noise reduction dependence on the aerodynamic loading is discussed. The influence of the microphone locations on the far-field spectra uncertainty is also studied. The Monte-Carlo method has been applied using the Delay-and-Sum and Clean-SC beamformers. The effect of the input uncertainty correlation, wind tunnel velocity, facility, and algorithm are examined.

In this master thesis project the initial steps for the design of a new wind tunnel
for aeroacoustic measurements are made. Well-documented sizing methods for
different wind tunnel parts were found in a literature study and were used
together with 2D CFD simulations to create a new wind tunnel design. Thick
corner vanes were used in this design with the purpose of using them as baffle
mufflers to create a better environment for aeroacoustic measurements inside the test section. The performance of the wind tunnel was evaluated thereafter by 3D CFD simulations. The 3D simulations provide an idea of the flow velocities, the flow uniformity, turbulence intensities, pressure losses and noise sources inside the wind tunnel. Since an existing wind tunnel fan and 42 kW motor was to be reused, noise measurements were done to find the noise characteristics of the fan-motor combination and to have an idea of how noise would propogate in
the environment were the new wind tunnel would be placed. After the noise
measurements, predictions of the transmission loss through the corner vanes
were made by using finite element analyses.