Results 271 to 280 of about 228,844 (310)
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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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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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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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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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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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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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SAE Technical Paper Series, 1974
<div class="htmlview paragraph">This paper describes a variety of methods employed in the past to modify or suppress jet noise. Some of the intriguing aspects of the factors that contribute to noise suppression are brought out. The paper concludes that a systematic study of the physics of jet suppression, in place of the ad hoc methods used in ...
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<div class="htmlview paragraph">This paper describes a variety of methods employed in the past to modify or suppress jet noise. Some of the intriguing aspects of the factors that contribute to noise suppression are brought out. The paper concludes that a systematic study of the physics of jet suppression, in place of the ad hoc methods used in ...
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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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The Journal of the Royal Aeronautical Society, 1954
During the past few years, the introduction of the large jet air liner has introduced new noises into the sky which has caused the public to be more aware than ever of the increasing nuisance value of aircraft taking off, landing, or on the ground. Much of this is being blamed unfairly on the jet air liner but the problem in any case remains with us ...
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During the past few years, the introduction of the large jet air liner has introduced new noises into the sky which has caused the public to be more aware than ever of the increasing nuisance value of aircraft taking off, landing, or on the ground. Much of this is being blamed unfairly on the jet air liner but the problem in any case remains with us ...
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