Akamine Masahito, Okamoto Koji, Teramoto Susumu, Tsutsumi Seiji
Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, 277-8561,
Graduate School of Engineering, University of Tokyo, Bunkyo, Tokyo, 113-8656,
J Acoust Soc Am. 2019 Jan;145(1):EL122. doi: 10.1121/1.5088493.
Acoustic-triggered conditional sampling analysis can extract the broadband-noise-related intermittent fluctuations from complicated schlieren visualization movies around the source region, which is difficult when using conventional methods. In this study, an analysis of the Mach wave radiation from a supersonic jet was performed. The extracted results properly captured the known features of the Mach waves and their sources (i.e., wavepacket at the jet boundary) and clearly showed the correlation between these near-field fluctuations and the far-field intermittent acoustic events. This analysis can potentially be applied to other broadband, intermittent turbulent noise and will provide a better understanding of their generation mechanisms.
