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On the relationship between acoustic energy density flux near the jet and far field acoustic intensityThe relationship between the distribution of the outflow of acoustic energy over the jet boundary and the far-field directivity and intensity distribution is established by measurement and analysis. The numerical and experimental procedures involved have been checked out by using a known source. The results indicate that the acoustic power output per unit length of the jet, in the region from which the sound emanates, peaks at approximately 9 diameters downstream. The acoustic emission for a jet Strouhal number of about 0.3 exceeds the emission for all other Strouhal numbers nearly everywhere along the measurement plane. However, the far-field peak intensity distribution obtained from the contribution of each station was found to depend on the spatial extent of the region where sound emanates from the jet, which, in turn, depends more on the far-field angle than on the Strouhal number. The implications of these results for sound suppression techniques are discussed.
Document ID
19740030450
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Maestrello, L.
(NASA Langley Research Center Hampton, Va., United States)
Date Acquired
August 7, 2013
Publication Date
October 1, 1973
Subject Category
Fluid Mechanics
Report/Patent Number
AIAA PAPER 73-988
Meeting Information
Meeting: Aero-Acoustics Conference
Location: Seattle, WA
Start Date: October 15, 1973
End Date: October 17, 1973
Sponsors: American Institute of Aeronautics and Astronautics
Accession Number
74A13200
Distribution Limits
Public
Copyright
Other

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