6—The Instability of Two Vortex Sheets Enclosing a Subsonic Jet due to Acoustic Radiation

1974 ◽  
Vol 72 (1) ◽  
pp. 79-91 ◽  
Author(s):  
N. Hardisty
Keyword(s):  
Acoustic Radiation ◽  
Vortex Sheets ◽  
Instability Waves ◽  
Subsonic Jet

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.

13.—The Instability of Two Vortex Sheets enclosing a Subsonic Jet due to an Acoustic Point Source

1975 ◽  
Vol 73 ◽  
pp. 215-229 ◽  
Author(s):  
N. Hardisty
Keyword(s):  
Point Source ◽  
Vortex Sheets ◽  
Instability Waves ◽  
Subsonic Jet

SynopsisThe propagation of sound from a point source placed in a subsonic jet separated by two plane 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.

Shear-layer acoustic radiation in an excited subsonic jet: experimental study

2005 ◽  
Vol 333 (10) ◽  
pp. 746-753 ◽  
Author(s):  
Vincent Fleury ◽  
Christophe Bailly ◽  
Daniel Juvé
Keyword(s):  
Experimental Study ◽  
Shear Layer ◽  
Acoustic Radiation ◽  
Subsonic Jet

Modeling and Prediction of Acoustic Resonance for Round Supersonic Jets

2000 ◽  
Author(s):  
A. W. Cary ◽  
W. W. Bower ◽  
A. B. Cain ◽  
E. J. Kershen
Keyword(s):  
Acoustic Waves ◽  
Sound Pressure ◽  
Acoustic Radiation ◽  
Acoustic Resonance ◽  
Supersonic Jets ◽  
Operating Conditions ◽  
Analysis Tool ◽  
Instability Waves ◽  
Round Jets ◽  
Modeling And Prediction

Abstract A computationally rapid analysis tool has been developed to compute the acoustic resonance of off-design supersonic jets known as “screech”. For the case of round jets, the computational model is described which is based on coupling analytical representations of each of the four components of the resonance: 1) the shear layer instability; 2) the vortex/shock interaction; 3) the upstream-propagating acoustic radiation; and 4) the receptive coupling of scattered acoustic waves and instability waves at the nozzle lip. Comparisons among predicted and measured sound pressure levels and frequencies of the resonance are presented for a range of jet operating conditions.

12.—The Instability due to Acoustic Radiation striking a Vortex Sheet on a Subsonic Stream

1973 ◽  
Vol 71 (2) ◽  
pp. 141-149
Author(s):  
N. Hardisty
Keyword(s):  
Mach Number ◽  
Sound Source ◽  
Acoustic Radiation ◽  
Vortex Sheet ◽  
Instability Waves ◽  
Two Fluids ◽  
Moving Fluid

SynopsisThe propagation of sound across a vortex sheet separating two fluids in relative subsonic motion is examined for both harmonic and impulsive sources, the sound source being in the moving fluid. It is found that instability waves arise in a certain region depending on M, the Mach number.

A model supersonic buried-nozzle jet: instability and acoustic wave scattering and the far-field sound

2015 ◽  
Vol 778 ◽  
pp. 189-215 ◽  
Author(s):  
Arnab Samanta ◽  
Jonathan B. Freund
Keyword(s):  
Far Field ◽  
Sound Waves ◽  
Vortex Sheets ◽  
Instability Waves ◽  
Acoustic Wave Scattering ◽  
Instability Modes ◽  
Source Mechanisms ◽  
Upstream Direction ◽  
Field Radiation ◽  
Hopf Method

We consider sound source mechanisms involving the acoustic and instability modes of dual-stream isothermal supersonic jets with the inner nozzle buried within an outer shroud-like nozzle. A particular focus is scattering into radiating sound waves at the shroud lip. For such jets, several families of acoustically coupled instability waves exist, beyond the regular vortical Kelvin–Helmholtz mode, with different shapes and propagation characteristics, which can therefore affect the character of the radiated sound. In our model, the coaxial shear layers are vortex sheets while the incident acoustic disturbances are the propagating shroud modes. The Wiener–Hopf method is used to compute their scattering at the sharp shroud edge to obtain the far-field radiation. The resulting far-field directivity quantifies the acoustic efficiency of different mechanisms, which is particularly important in the upstream direction, where the results show that the scattered sound is more intense than that radiated directly by the shear-layer modes.

Gasdynamic and Acoustic Characteristics of a Subsonic Jet-Edge Rod Generator of Acoustic Radiation

2020 ◽  
Vol 93 (5) ◽  
pp. 1179-1190
Author(s):  
K. N. Volkov ◽  
V. N. Emel’yanov ◽  
A. V. Efremov ◽  
A. I. Tsvetkov
Keyword(s):  
Acoustic Radiation ◽  
Acoustic Characteristics ◽  
Subsonic Jet
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