Abstract
Wavelet transform has become a common tool for processing non-stationary signals in many different fields. The present paper reports a review of some applications of wavelet in aeroacoustics with a special emphasis on the analysis of experimental data taken in compressible jets. The focus is on three classes of wavelet-based signal processing procedures: (i) conditional statistics; (ii) acoustic and hydrodynamic pressure separation; (iii) stochastic modeling. The three approaches are applied to an experimental database consisting of pressure time series measured in the near field of a turbulent jet. Future developments and possible generalization to other applications, e.g., airframe or propeller noise, are also discussed.
Highlights
Wavelet transform is widely used as an efficient tool to extract localized features from random signals, whatever the nature of the analyzed quantity
The present paper reports a review of some applications of wavelet in aeroacoustics with a special emphasis on the analysis of experimental data taken in compressible jets
The focus is on three classes of wavelet-based signal processing procedures: (i) conditional statistics; (ii) acoustic and hydrodynamic pressure separation; (iii) stochastic modeling
Summary
Wavelet transform is widely used as an efficient tool to extract localized features from random signals, whatever the nature of the analyzed quantity. The correlation between the intermittent and localized nature of those flow structures and the noise production mechanism has been verified by several authors [14,15,16,17], and it is nowadays recognized that a correct prediction of the jet far-field noise can only be accomplished if such an intermittent dynamic is considered (e.g., [18]) Within this context, due to their temporally localized nature, wavelet analysis has been applied successfully to extract intermittent sound sources in jet flows. The main features of the selected methodologies are briefly worked out, along with a review of the relevant literature To better exploit their properties, examples of applications will be given by considering an experimental database consisting of pressure data taken in the near field of a single stream-compressible sub-sonic jet.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
