Zachary Anderson, Brigham Young University
Physical Sciences
Correlation analysis is useful in extracting spatiotemporal relationships between signals and can be used to examine features of near-field jet noise for source properties. Characteristic correlation envelopes determined by Harker et al. [JASA 133, EL458 (2013)] can be used to relate correlation lengths to fine and large-scale turbulent structures. As an extension, cross-correlation shows spatial variation in jet noise and further reveals the transition between short (fine-scale) and long (large-scale) correlation lengths. These analyses are applied to a military jet dataset of a ground based linear microphone array positioned 11.6 m from the jet axis. Correlation analyses over multiple engine conditions and observation directions are reported. In particular, a maximum correlation coefficient greater than 0.5 exists over a range spanning multiple wavelengths in the region of greatest overall sound pressure level at military power. [Work supported by ONR.]