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Comparison of Noise Source Localization Data with Flow Field Data Obtained in Cold Supersonic Jets and Implications Regarding Broadband Shock NoisePhased array noise source localization have been compared with 2 types of flow field data (BOS and PIV). The data show that: 1) the higher frequency noise in a BBSN hump is generated further downstream than the lower frequency noise. This is due to a) the shock spacing decreasing and b) the turbulent structure size increasing with distance downstream. 2) BBSN can be created by very weak shocks. 3) BBSN is not created by the strong shocks just downstream of the nozzle because the turbulent structures have not grown large enough to match the shock spacing. 4) The point in the flow where the shock spacing equals the average size of the turbulent structures is a hot spot for shock noise. 5) Some of the shocks responsible for producing the first hump also produce the second hump.
Document ID
Document Type
Podboy, Gary
(NASA Glenn Research Center Cleveland, OH, United States)
Wernet, Mark
(NASA Glenn Research Center Cleveland, OH, United States)
Clem, Michelle
(NASA Glenn Research Center Cleveland, OH, United States)
Fagan, Amy
(NASA Glenn Research Center Cleveland, OH, United States)
Date Acquired
July 3, 2014
Publication Date
April 23, 2013
Subject Category
Fluid Mechanics And Thermodynamics
Aircraft Design, Testing And Performance
Report/Patent Number
Meeting Information
Acoustics Technical Working Group(Cleveland, Ohio)
Funding Number(s)
WBS: WBS 473452.
Distribution Limits
Work of the US Gov. Public Use Permitted.
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