Noisy Kites? Exploring Noise Annoyance for Airborne Wind Energy Systems with a Laboratory Listening Experiment

Comparison of cavity geometries for a microphone array in an open-jet wind-tunnel experiment

This paper analyses the influence of microphone cavity geometry on beamforming measurements with a turbulent boundary layer present on the microphone array. A 16- microphone array was tested in the anechoic open-jet wind tunnel of the Delft University of Technology. The array was placed on a flat plate mounted flush with the exit nozzle of the...

Comparison between analog and digital microphone phased arrays for aeroacoustic measurements

Microphone arrays are useful measurement devices for estimating the location and strength of sound sources. Numerous comparative studies have been conducted regarding the performance of acoustic imaging methods in the past, but literature lacks of a systematic investigation on the role of the hardware on the measurements. This research...

Trailing edge serrations: Effect of their flap angle on flow and acoustics

Trailing edge serrations have been proven to work as a passive noise reduction device. Nevertheless, they have also previously been found to increase noise in a particular frequency range, argued in earlier research to be due to the misalignment of the serrations with the direction of the flow in the wake. It emerges as a high-frequency noise...

Acoustic measurements of a DU96-W-180 airfoil with flow-misaligned serrations at a high Reynolds number in a closed-section wind tunnel

Trailing-edge serrations are passive noise reduction add-ons widely used in wind-turbine applications. This study presents acoustic beamforming results of microphone array measurements of a cambered airfoil (DU96-W-180) in a closed-section wind-tunnel at a Reynolds number of industrial interest. Two different serration geometries with different...

Near-wall pressure fluctuations over noise reduction add-ons

Broadband Trailing-Edge Noise Reduction Using Permeable Metal Foams