Direct Computation of Mach Wave Radiation in an Axisymmetric Supersonic Jet

AIAA Journal ◽  
10.2514/2.15 ◽  
1997 ◽  
Vol 35 (10) ◽  
pp. 1574-1580 ◽  
Author(s):  
Brian E. Mitchell ◽  
Sanjiva K. Lele ◽  
Parviz Moin
Keyword(s):  
Supersonic Jet ◽  
Wave Radiation ◽  
Direct Computation ◽  
Mach Wave

Direct computation of Mach wave radiation in an axisymmetric supersonic jet

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1574-1580
Author(s):  
Brian E. Mitchell ◽  
Sanjiva K. Lele ◽  
Parviz Moin
Keyword(s):  
Supersonic Jet ◽  
Wave Radiation ◽  
Direct Computation ◽  
Mach Wave

scholarly journals Conditional sampling analysis of high-speed schlieren movies of Mach wave radiation in a supersonic jet

2019 ◽  
Vol 145 (1) ◽  
pp. EL122-EL128 ◽  
Author(s):  
Masahito Akamine ◽  
Koji Okamoto ◽  
Susumu Teramoto ◽  
Seiji Tsutsumi
Keyword(s):  
High Speed ◽  
Supersonic Jet ◽  
Wave Radiation ◽  
Conditional Sampling ◽  
Mach Wave

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.

scholarly journals Mach Wave Radiation from a Jet at Mach 1.92

2001 ◽  
Vol 13 (9) ◽  
pp. S3-S3 ◽  
Author(s):  
R. Darke ◽  
J. B. Freund
Keyword(s):  
Wave Radiation ◽  
Mach Wave

A study of Mach wave radiation using active control

2011 ◽  
Vol 681 ◽  
pp. 261-292 ◽  
Author(s):  
M. KEARNEY-FISCHER ◽  
J.-H. KIM ◽  
M. SAMIMY
Keyword(s):  
Large Scale ◽  
Near Field ◽  
Pressure Fluctuations ◽  
Hydrodynamic Pressure ◽  
Detailed Examination ◽  
Operating Conditions ◽  
Wave Radiation ◽  
Stagnation Temperature ◽  
Azimuthal Mode ◽  
Mach Wave

Mach wave radiation is one of the better understood sources of jet noise. However, the exact conditions of its onset are difficult to determine and the literature to date typically explores Mach wave radiation well above its onset conditions. In order to determine the conditions for the onset of Mach wave radiation and to explore its behaviour during onset and beyond, three ideally expanded jets with Mach numbers Mj = 0.9, 1.3 and 1.65 and stagnation temperature ratios ranging over To/T∞ = 1.0–2.5 (acoustic Mach number 0.83–2.10) were used. Data are collected using a far-field microphone array, schlieren imaging and streamwise two-component particle image velocimetry. Using arc filament plasma actuators to force the jet provides an unprecedented tool for detailed examination of Mach wave radiation. The response of the jet to various forcing parameters (combinations of one azimuthal mode m = 0, 1 and 3 and one Strouhal number StDF = 0.09–3.0) is explored. Phase-averaged schlieren images clearly show the onset and evolution of Mach wave radiation in response to both changes in the jet operating conditions and forcing parameters. It is observed that Mach wave radiation is initiated as a coalescing of the near-field hydrodynamic pressure fluctuations in the immediate vicinity of the large-scale structures. As the jet exit velocity increases, the hydrodynamic pressure fluctuations coalesce, first into a curved wavefront, then flatten into the conical wavefronts commonly associated with Mach wave radiation. The results show that the largest and most coherent structures (e.g. forcing with m = 0 and StDF ~ 0.3) produce the strongest Mach wave radiation. Conversely, Mach wave radiation is weakest when the structures are the least coherent (e.g. forcing with m = 3 and StDF > 1.5).

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