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Effect of Microjet Injection on Supersonic Jet NoiseThe effect of microjet (jet) injection on the noise from supersonic jets is investigated. Three convergent-divergent (C-D) nozzles and one convergent nozzle, all having the same exit diameters, are used in the study. The jets are injected perpendicular to the primary jet close to the nozzle lip from six equally-spaced ports having a jet-to-primary-jet diameter ratio of 0.0054. Effects in the over-expanded, fully expanded as well as underexpanded flow regimes are explored. Relative to the effect on subsonic jets, larger reductions in the overall sound pressure level (OASPL) are achieved in most supersonic conditions. The largest reductions are typically associated with suppression of screech and transonic tones. For a shock-free, fully expanded case, the OASPL reductions achieved are comparable to that in the subsonic case; the same correlation, found for subsonic jet noise reduction at shallow observation angle, applies.
Document ID
20110016099
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Authors
Zaman, K. B. M. Q.
(NASA Glenn Research Center Cleveland, OH, United States)
Podboy, G. G.
(NASA Glenn Research Center Cleveland, OH, United States)
Date Acquired
August 25, 2013
Publication Date
June 7, 2010
Subject Category
Acoustics
Report/Patent Number
E-17967
Meeting Information
Meeting: 16th AIAA/CEAS Aeroacoustics Conference
Location: Stockholm
Country: Sweden
Start Date: June 7, 2010
End Date: June 9, 2010
Sponsors: American Inst. of Aeronautics and Astronautics
Funding Number(s)
WBS: WBS 984754.02.07.03.17.04
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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