Instability waves as a source of subsonic jet noise

SummaryThe propagation of sound in a subsonic jet separated by two vortex sheets from two semi-infinite still media is considered and it is found that instability waves arise at particular points on the vortex sheets and that their effect is confined to certain regions.

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Subsonic Jet Noise Source Location as a Function of Nozzle Geometry

AIAA Scitech 2019 Forum ◽

10.2514/6.2019-0250 ◽

2019 ◽

Author(s):

Nick P. Breen ◽

Krishan K. Ahuja

Keyword(s):

Noise Source ◽

Jet Noise ◽

Source Location ◽

Nozzle Geometry ◽

Subsonic Jet

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A prediction method for the effects of flight on subsonic jet noise

Journal of Sound and Vibration ◽

10.1016/0022-460x(77)90425-4 ◽

1977 ◽

Vol 53 (3) ◽

pp. 435-453 ◽

Cited By ~ 17

Author(s):

B.J. Cocking

Keyword(s):

Jet Noise ◽

Prediction Method ◽

Subsonic Jet

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Subsonic Jet Noise (Including Effect of Convection)

Aerodynamic Noise - Springer Aerospace Technology ◽

10.1007/978-1-4614-5019-1_5 ◽

2012 ◽

pp. 73-82

Author(s):

Tarit Bose

Keyword(s):

Jet Noise ◽

Subsonic Jet

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Effect of nozzle exit conditions on subsonic jet noise

17th AIAA/CEAS Aeroacoustics Conference (32nd AIAA Aeroacoustics Conference) ◽

10.2514/6.2011-2704 ◽

2011 ◽

Cited By ~ 11

Author(s):

Khairul Zaman

Keyword(s):

Nozzle Exit ◽

Jet Noise ◽

Subsonic Jet

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On the effect of swirling motion of sources on subsonic jet noise

Journal of Sound and Vibration ◽

10.1016/s0022-460x(73)80285-8 ◽

1973 ◽

Vol 29 (3) ◽

pp. 281-293 ◽

Cited By ~ 8

Author(s):

H.K. Tanna

Keyword(s):

Jet Noise ◽

Subsonic Jet

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Downstream subsonic jet noise: link with vortical structures intruding into the jet core

Comptes Rendus Mécanique ◽

10.1016/s1631-0721(02)01499-7 ◽

2002 ◽

Vol 330 (8) ◽

pp. 527-533 ◽

Cited By ~ 5

Author(s):

Christophe Bogey ◽

Christophe Bailly

Keyword(s):

Jet Noise ◽

Vortical Structures ◽

Subsonic Jet

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Subsonic Jet Noise from Nonaxisymmetric and Tabbed Nozzles

AIAA Journal ◽

10.2514/2.1029 ◽

2000 ◽

Vol 38 (4) ◽

pp. 592-599 ◽

Cited By ~ 77

Author(s):

Christopher K. W. Tam ◽

K. B. M. Q. Zaman

Keyword(s):

Jet Noise ◽

Subsonic Jet

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The role of shear-layer instability waves in jet exhaust noise

Journal of Fluid Mechanics ◽

10.1017/s0022112077001700 ◽

1977 ◽

Vol 80 (2) ◽

pp. 321-367 ◽

Cited By ~ 347

Author(s):

C. J. Moore

Keyword(s):

Shear Layer ◽

Large Scale ◽

Broad Band ◽

Jet Noise ◽

Acoustic Power ◽

Thermal Fluctuations ◽

Excess Noise ◽

Number Range ◽

Instability Waves ◽

Noise Measurements

Large-scale structures in the form of instability waves are an inherent part of a shearlayer mixing process. Such structures are shown to be present in an acoustically and aerodynamically well behaved jet even at high Mach numbers. They do not directly radiate significant acoustic power in a subsonic jet, but do govern the production of the turbulent fluctuations which radiate broad-band jet noise. Over the whole subsonic Mach number range, a significant increase in jet noise can be produced by exciting the shear layer with a fluctuating pressure at the nozzle of only 0·08 % of the jet dynamic head but with the correct Strouhal number. Such excitation by internal acoustic, aerodynamic or thermal fluctuations could explain the variability of jet noise measurements between different rigs and could also be responsible for some components of ‘excess’ noise.

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