Aeroacoustic analysis of various noise sources: comparison of jet nozzles on BeamformX

Abstract

This work revolves around the research in aeroacoustics: first an introduction to the concepts of noise, aeroacoustics and the importance of noise monitoring, identification and control will be presented. After that, the main tool used in the experiments and measurements will be introduced: BeamformX, a cutting edge technology software that has been the principal asset and way to record, identify and quantify the various noise sources with which experiments have been conducted. The basics of this tool will be explained, with easy-to-understand explanations and graphics, so the reader can feel comfortable with the terminology and later results interpretation and plots. Next, the necessary equipment, tooling and experiment setup will be explained, in order to get somehow standardized experiments and comparable results from one test to another, with the intention of showing how the experiments have been conducted and how they could be reproduced and further validated in future work. The reader will find two main sections of experiments: general tests, where simple noise sources will be analyzed, and have the intention of helping understand the basic concepts of aeroacoustics as well as the BeamformX software and getting used to the general equipment and methodology, and comparison of jet nozzles, where different shaped nozzles have been tested at different flow speeds with the use of a compressed jet facility. With these, the experiment results will be presented in a comprehensible way, comparing the values obtained from one noise source to another and analyzing the reasons behind these results, extracting useful and reasonable cause-effect relationships and trends. Last, some conclusions of the work done, both generally speaking and with regards to the specific experiments and results already commented, and some ideas for future works or research in the area are commented.