Microphone Arrays for Aeroacoustic Measurements Theory and Practice- Course Notes

Abstract

Aim of this course is to improve the knowledge for the practical application of microphone array measurements in wind tunnels, including the post-processing and the interpretation of the achieved results. Test engineers can participate to obtain the necessary knowledge to improve the quality of aeroacoustic measurements with microphone arrays and prevent costly errors. Contractors and end-users of array measurement results will learn how to assess the potential of aeroacoustic wind tunnel measurements and how to interpret the achieved results appropriately. In this course a knowledge base regarding the necessary theoretical background, practical knowledge about the hardware requirements and the potential of post processing will be taught. The theoretical part will concentrate on those aspects of aeroacoustics relevant to microphone array measurements. Besides giving lectures on the fundamental aspects, special emphasis will be placed on solutions of the practical problems which are faced during the implementation of this technique in wind tunnels. During practice the participants will have the opportunity in small groups to carry out recording and evaluation of data, with special emphasis being given to the impact of experimental settings on the beamforming results. The post processing and particularly the various deconvolution algorithms, including their advantages and disadvantages, will be explained and demonstrated.