Abstract by Jacob Ward
Physics and Astronomy
Calculating the frequency-dependent apparent source location of jet noise using peak cross-correlation between nearfield and far-field microphone arrays
The apparent acoustic source region of jet noise varies as a function of frequency. In this study, the variation of the apparent maximum source location with frequency is considered for a laboratory scale Mach-1.8 jet. The source location is ascertained for one-third octave bands by evaluating peak cross-correlation between near-field linear microphone arrays at three sideline distances and a far-field microphone arc. The impact of the hydrodynamic field on correlation results is considered. Apparent source locations determined by these means are compared with intensity analyses for the same jet. Correlational methods together with filtering can provide a straightforward measure of the effective acoustic origin as a function of frequency and thus inform optimal microphone array layout for specific frequency regimes.