Development of an Empirical Methods for Predicting Jet Mixing Noise of Cold Flow Rectangular Jets
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Page : 100 pages
File Size : 39,2 MB
Release : 1999
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Page : 100 pages
File Size : 39,2 MB
Release : 1999
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Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 98 pages
File Size : 32,29 MB
Release : 2018-05-30
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ISBN : 9781720478560
This report presents an empirical method for predicting the jet mixing noise levels of cold flow rectangular jets. The report presents a detailed analysis of the methodology used in development of the prediction method. The empirical correlations used are based on narrow band acoustic data for cold flow rectangular model nozzle tests conducted in the NASA Langley Jet Noise Laboratory. There were 20 separate nozzle test operating conditions. For each operating condition 60 Hz bandwidth microphone measurements were made over a frequency range from 0 to 60,000 Hz. Measurements were performed at 16 polar directivity angles ranging from 45 degrees to 157.5 degrees. At each polar directivity angle, measurements were made at 9 azimuth directivity angles. The report shows the methods employed to remove screech tones and shock noise from the data in order to obtain the jet mixing noise component. The jet mixing noise was defined in terms of one third octave band spectral content, polar and azimuth directivity, and overall power level. Empirical correlations were performed over the range of test conditions to define each of these jet mixing noise parameters as a function of aspect ratio, jet velocity, and polar and azimuth directivity angles. The report presents the method for predicting the overall power level, the average polar directivity, the azimuth directivity and the location and shape of the spectra for jet mixing noise of cold flow rectangular jets.Russell, James W.Langley Research CenterAEROACOUSTICS; PREDICTION ANALYSIS TECHNIQUES; AERODYNAMIC NOISE; JET MIXING FLOW; COLD FLOW TESTS; ACOUSTIC FREQUENCIES; DATA REDUCTION; MICROPHONES; SCREECH TONES; SHOCK WAVES; NARROWBAND; AZIMUTH; NOZZLE GEOMETRY
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Page : 182 pages
File Size : 28,87 MB
Release : 2000
Category : Astronautics
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Page : 938 pages
File Size : 15,59 MB
Release : 2000-07
Category : Government publications
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Page : 272 pages
File Size : 47,69 MB
Release : 1991
Category : Aeronautics
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Page : 514 pages
File Size : 46,87 MB
Release : 1993
Category : Airplane sounds
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Author : American Institute of Aeronautics and Astronautics
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Page : 960 pages
File Size : 30,59 MB
Release : 2005
Category : Aeronautics
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Author : Harvey H. Hubbard
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Page : 620 pages
File Size : 33,92 MB
Release : 1991
Category : Aerodynamic noise
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Page : 116 pages
File Size : 44,58 MB
Release : 1962
Category : Aeronautics
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Page : 998 pages
File Size : 11,91 MB
Release : 1989
Category : Aeronautics
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A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA)