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Reflected shock tube experiments on aeroacoustic signature of hot jets

Jahromi, I. B ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1007/s12206-017-0725-9
  3. Abstract:
  4. We used a reflected shock tube to investigate the acoustic signature of a hot jet at the far-field. Experiments were performed at Mach = 1.4 and a total temperature of Tt = 950 Kelvin. Far-field acoustic signatures of the hot jet at six polar angles θ = 15˚ to θ = 90˚ from the jet axis) were measured and imaged by the means of continuous wavelet transform in scalograms. The results were compared with experiments from a steady test facility at similar test conditions. Further, the primary characteristics of noise events in jet far-field were compared with analytical models considering wavepacket as the main source of jet noise. The results indicate that higher frequency events at θ = 90˚ occur with a small time shift relative to the low azimuthal mode base event. This phenomenon might be the main reason why the acoustic signal at the side angles behaves more noisily than at low polar angles. © 2017, The Korean Society of Mechanical Engineers and Springer-Verlag GmbH Germany
  5. Keywords:
  6. Acoustic event ; Hot jet aeroacoustics ; Shock tube ; Wavepacket ; Acoustic variables measurement ; Aeroacoustics ; Shock tubes ; Wave packets ; Wavelet transforms ; Acoustic events ; Acoustic signals ; Acoustic signature ; Continuous wavelet ; Continuous wjavascript:;avelet transform ; Higher frequencies ; Jet aeroacoustics ; Total temperatures ; Acoustic noise
  7. Source: Journal of Mechanical Science and Technology ; Volume 31, Issue 8 , 2017 , Pages 3811-3820 ; 1738494X (ISSN)
  8. URL: https://link.springer.com/article/10.1007/s12206-017-0725-9