0801 Experimental Study on the Velocity Distribution in the Supersonic Jet Shear Layer and the Acoustic Waves

2015 ◽  
Vol 2015 (0) ◽  
pp. _0801-1_-_0801-3_ ◽  
Author(s):  
Yuta Ozawa ◽  
Taku Nonomura ◽  
Kozo Fujii ◽  
Makoto Yamamoto ◽  
Yuya Mamori
Keyword(s):  
Experimental Study ◽  
Velocity Distribution ◽  
Shear Layer ◽  
Acoustic Waves ◽  
Supersonic Jet

Computational Aeroacoustic Analysis of Overexpanded Supersonic Jet Impingement on a Flat Plate With/Without Hole

2007 ◽  
Author(s):  
Soshi Kawai ◽  
Seiji Tsutsumi ◽  
Ryoji Takaki ◽  
Kozo Fujii
Keyword(s):  
Shear Layer ◽  
Flat Plate ◽  
Acoustic Waves ◽  
Near Field ◽  
Supersonic Jet ◽  
Jet Impingement ◽  
Wave Radiation ◽  
Shock Cell ◽  
Mach Wave ◽  
Source Power

Aeroacoustic mechanisms of an axisymmetric over-expanded supersonic jet impinging on a flat plate with and without hole are numerically investigated. High-order weighted compact nonlinear scheme is used to simulate the unsteady flow including shock waves and sound radiation in the near field of the jet. Analyses of unsteady flowfield and related near-sound field reasonably identify three major noise generation mechanisms, that is, noises from Mach wave, shock cell-shear layer interaction and small fluctuations of jet shear layer. Especially, intense noise radiation in the form of Mach waves and its reflection at the plate predominates the noises from the other two finer sources. The simulated distributions of sound source power and its frequency along the jet axis qualitatively well coincide with typical experimental data used in NASA SP-8072. Similar sound pressure spectrum shape is obtained both the cases of flat plate with and without hole, but the case of without hole shows higher SPL by several dB than that of with hole due to the stronger Mach wave radiation. Aeroacoustic flowfield is drastically affected by the Reynolds number because the jet shear layer instability directly causes the strength of acoustic waves.

EXPERIMENTAL STUDY OF NONLINEARITY IN FREE PROGRESSIVE ACOUSTIC WAVES IN AIR AT 20 kHz

1979 ◽  
Vol 40 (C8) ◽  
pp. C8-336-C8-340 ◽  
Author(s):  
Dr. J.A. GALLEGO-JUAREZ ◽  
L. GAETE-GARRETON
Keyword(s):  
Experimental Study ◽  
Acoustic Waves

Experimental study of shear-layer/acoustics coupling in Mach 5 cavity flow

AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 242-252
Author(s):  
O. H. Unalmis ◽  
N. T. Clemens ◽  
D. S. Dolling
Keyword(s):  
Experimental Study ◽  
Shear Layer ◽  
Cavity Flow

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

scholarly journals Акустические характеристики автоколебательного процесса, возникающего при взаимодействии сверхзвуковой недорасширенной струи с цилиндрической полостью

2020 ◽  
Vol 90 (5) ◽  
pp. 733
Author(s):  
К.Н. Волков ◽  
В.Н. Емельянов ◽  
А.В. Ефремов ◽  
А.И. Цветков
Keyword(s):  
Atmospheric Pressure ◽  
Acoustic Waves ◽  
Supersonic Jet ◽  
Cavity Resonator ◽  
Dynamic Structure ◽  
Gas Jet ◽  
Working Pressure ◽  
Gas Dynamic ◽  
Physical Pattern ◽  
Cylindrical Cavities

In high-pressure gas-jet emitters, the source of sound energy is kinetic energy of gas jet at supercritical pressure ratios between the working pressure and the atmospheric pressure. Under certain conditions, interaction of a supersonic jet with the resonator is accompanied by powerful self-excited oscillating process with the generation of acoustic waves into the environment and cavity resonator. A model of a self-excited oscillating process arising from the interaction of non-isobaric jet with semi-closed cylindrical cavities, allowing to distinguish typical elements of gas-dynamic structure of the forming flow, is considered. The physical pattern of the flow in the cavity of gas-jet emitter is discussed, and a study of the dependence of the characteristics of the self-excited oscillating process on the gas-dynamic and geometric parameters is performed.

Theoretical and experimental study of linear motors using surface acoustic waves

1998 ◽  
Vol 70 (1-2) ◽  
pp. 67-74 ◽  
Author(s):  
Philippe Hélin ◽  
Véronique Sadaune ◽  
Christian Druon
Keyword(s):  
Experimental Study ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Linear Motors
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