Preliminary Investigation of Multilobe Fighter Jet Noise Sources Using Acoustical Holography

2017 ◽  
Author(s):  
Alan T. Wall ◽  
Kevin M. Leete ◽  
Kent L. Gee ◽  
Tracianne B. Neilsen ◽  
Michael M. James ◽  
...  
Keyword(s):  
Preliminary Investigation ◽  
Jet Noise ◽  
Noise Sources ◽  
Acoustical Holography

scholarly journals Jet-Surface Interaction Test: Phased Array Noise Source Localization Results

2012 ◽  
Author(s):  
Gary G. Podboy
Keyword(s):  
Source Localization ◽  
Phased Array ◽  
Noise Source ◽  
Jet Noise ◽  
Companion Paper ◽  
Far Field ◽  
Sound Waves ◽  
Axial Distribution ◽  
Noise Sources ◽  
Interaction Test

An experiment was conducted to investigate the effect that a planar surface located near a jet flow has on the noise radiated to the far-field. Two different configurations were tested: 1) a shielding configuration in which the surface was located between the jet and the far-field microphones, and 2) a reflecting configuration in which the surface was mounted on the opposite side of the jet, and thus the jet noise was free to reflect off the surface toward the microphones. Both conventional far-field microphone and phased array noise source localization measurements were obtained. This paper discusses phased array results, while a companion paper discusses far-field results. The phased array data show that the axial distribution of noise sources in a jet can vary greatly depending on the jet operating condition and suggests that it would first be necessary to know or be able to predict this distribution in order to be able to predict the amount of noise reduction to expect from a given shielding configuration. The data obtained on both subsonic and supersonic jets show that the noise sources associated with a given frequency of noise tend to move downstream, and therefore, would become more difficult to shield, as jet Mach number increases. The noise source localization data obtained on cold, shock-containing jets suggests that the constructive interference of sound waves that produces noise at a given frequency within a broadband shock noise hump comes primarily from a small number of shocks, rather than from all the shocks at the same time. The reflecting configuration data illustrates that the law of reflection must be satisfied in order for jet noise to reflect off of a surface to an observer, and depending on the relative locations of the jet, the surface, and the observer, only some of the jet noise sources may satisfy this requirement.

Military jet noise source imaging using multisource statistically optimized near-field acoustical holography

2016 ◽  
Vol 139 (4) ◽  
pp. 1938-1950 ◽  
Author(s):  
Alan T. Wall ◽  
Kent L. Gee ◽  
Tracianne B. Neilsen ◽  
Richard L. McKinley ◽  
Michael M. James
Keyword(s):  
Noise Source ◽  
Near Field ◽  
Jet Noise ◽  
Source Imaging ◽  
Acoustical Holography

Experimental Investigation on the Jet Noise Sources for Chevron Nozzles in Under-expanded Condition

2021 ◽  
Author(s):  
Hasan Kamliya Jawahar ◽  
Stefano Meloni ◽  
Roberto Camussi ◽  
Mahdi Azarpeyvand
Keyword(s):  
Experimental Investigation ◽  
Jet Noise ◽  
Noise Sources ◽  
Chevron Nozzles

Conditional Sampling for Jet Noise Sources Characterization

AIAA Journal ◽  
1978 ◽  
Vol 16 (11) ◽  
pp. 1121-1122
Author(s):  
Leon Avezard ◽  
Claude Dahan ◽  
Georges Elias ◽  
Annie Lelarge ◽  
Jean Maulard ◽  
...  
Keyword(s):  
Jet Noise ◽  
Conditional Sampling ◽  
Noise Sources
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