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Separation of Core Noise and Jet Noise
AIAA Journal, 1980A method of identificatio n and measurement of c*re W\«» and let noise separately has been developed based on cross-correlation of signals from microphones located at ...
S. P. Parthasarathy +2 more
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Theoretical and Computational Fluid Dynamics, 1998
Jet noise research was initiated by Sir James Lighthill in 1952. Since that time, the development of jet noise theory has followed a very tortuous path. This is, perhaps, not surprising for the understanding of jet noise is inherently tied to the understanding of turbulence in jet flows. Even now, our understanding of turbulence is still tenuous.
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Jet noise research was initiated by Sir James Lighthill in 1952. Since that time, the development of jet noise theory has followed a very tortuous path. This is, perhaps, not surprising for the understanding of jet noise is inherently tied to the understanding of turbulence in jet flows. Even now, our understanding of turbulence is still tenuous.
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Effects of Jet Noise on Mortality Rates
British Journal of Audiology, 1979The test area is in the 90 dBA contour, for 1970–1980, and contains about 100 000 people, under the landing patterns at Los Angeles International Airport. A control area has approximately the same number of people, contiguous to the test area with racial distribution and income the same within a few percent. We can control age distribution by mortality
W C, Meecham, N, Shaw
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Changes of Jet Noise by Mixing and an Upper Limit on Jet Noise Production
The Journal of the Acoustical Society of America, 1957A simple analysis is given of the effect on jet noise by mixing with an induced secondary air flow. The combination of the secondary air with the primary air of the jet creates a new jet stream of larger area and lower velocity. Power level, spectrum, and directivity changes are presented.
Peter J. Westervelt +2 more
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On the Aerodynamic Noise of a Turbulent Jet
Journal of the Aerospace Sciences, 1961Summary A new model is advanced for analyzing the broad-spectrum noise of a turbulent jet. The shear layer bounding the turbulent jet is assumed to play an important role in modifying the "quadrupole sound radiation" from the interior. To the sound-emit ting, small-scale turbulent eddies (with frequencies much higher than those of large-scale eddies),
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Noise and Noise Reduction in Supersonic Jets
2018This paper describes a novel noise reduction method for supersonic jets. It involves the injection of relatively small amounts of air into the diverging section of a convergent-divergent nozzle. The air is injected through a series of injectors that are aligned axially. The injected air diverts the jet core flow and forms “fluid inserts.” These inserts
Philip J. Morris, Dennis K. McLaughlin
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5th AIAA/CEAS Aeroacoustics Conference and Exhibit, 1999
Noise related restrictions and rules have been increasing all over the world. Between 1997 and 2017 aircraft traffic is projected to double. Increased impact on population due to the traffic growth needs to be mitigated by technology to reduce noise. If noise reductions are not achieved, the noise restrictions around airports may increase significantly
Belur Shivashankara, Thonse Bhat
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Noise related restrictions and rules have been increasing all over the world. Between 1997 and 2017 aircraft traffic is projected to double. Increased impact on population due to the traffic growth needs to be mitigated by technology to reduce noise. If noise reductions are not achieved, the noise restrictions around airports may increase significantly
Belur Shivashankara, Thonse Bhat
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Reduction of peak jet noise using jet refraction
Journal of Sound and Vibration, 1972The directivity pattern of sound generated by a subsonic jet exhibits a peak at angles between 15° and 45° to the jet axis decreasing to a minimum on the axis. Theoretical and experimental investigations have previously demonstrated that this minimum is due to refraction of sound by the jet flow.
P. J. Morris, W. Richarz, H. S. Ribner
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4th Aeroacoustics Conference, 1977
The fundamentals of jet noise generation and suppression have been studied in great detail over the past twenty-five years. Considerable progress has been made recently in our understanding of this subject, though some aspects of it remain perplexing. The importance of accounting for the influence of the jets mean flow in shrouding acoustic sources is ...
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The fundamentals of jet noise generation and suppression have been studied in great detail over the past twenty-five years. Considerable progress has been made recently in our understanding of this subject, though some aspects of it remain perplexing. The importance of accounting for the influence of the jets mean flow in shrouding acoustic sources is ...
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Jet noise and the effects of jet forcing
2007This paper gives a review of the experimental situation regarding the acoustic field of axisymmetric jets subject to controlled excitation. Two very different types of response are found in the literature; in one the response to tonal forcing involves a significant reduction in the broadband noise signal except in frequency bands around the tone and ...
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