Design of an Optimized Acoustic Array for Aero-acoustic Research in an Open-jet Anechoic Wind Tunnel

Master thesis (2017)

Authors

S. Luesutthiviboon Aerospace Engineering

Contributors

M. Snellen (supervisor 1)
P. Sijtsma (supervisor 1)
A.M.N. Malgoezar (supervisor 1)
Faculty
Aerospace Engineering
Copyright: © 2017 Salil Luesutthiviboon
Optimization Design Acoustic array
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Published Date

22-11-2017

Language

English

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Faculty

Aerospace Engineering

Abstract

This work aims to determine the optimal microphone placement on an acoustic array of TU Delft’s ‘V-tunnel’ which is used for beamforming in aero-acoustic studies. The beamforming performance is driven by two parameters; the Maximum Side lobe Level (MSL) and the Main Lobe Width (MLW). The array design should give a good trade-off between these parameters. The proposed optimization method has two optimization loops. First, the main loop consists of design variables used to collectively describe the distribution of microphones. Then the nested loop generates arrays which satisfy the geometry descriptions from the main loop. Finally, the main loop searches for the optimal design variables. The optimized array is able to achieve the MSL below -15 dB up to the distance approximately four times the MLW around the main lobe. Experimental validation was also carried out to compare the optimized array’s performance with a benchmark array and an array from the beginning of the optimization.