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Impact of Air Injection on Jet NoiseThe objective of this viewgraph presentation is to review the program to determine impact of core fluidic chevrons on noise produced by dual stream jets (i.e., broadband shock noise - supersonic, and mixing noise - subsonic and supersonic). The presentation reviews the sources of jet noise. It shows designs of Generation II Fluidic Chevrons. The injection impacts shock structure and stream disturbances through enhanced mixing. This may impact constructive interference between acoustic sources. The high fan pressures may inhibit mixing produced by core injectors. A fan stream injection may be required for better noise reduction. In future the modification of Gen II nozzles to allow for some azimuthal control: will allow for higher mass flow rates and will allow for shallower injection angles A Flow field study is scheduled for spring, 2008 The conclusions are that injection can reduce well-defined shock noise and injection reduces mixing noise near peak jet noise angle
Document ID
20080002268
Acquisition Source
Langley Research Center
Document Type
Reprint (Version printed in journal)
Authors
Henderson, Brenda (NASA Langley Research Center Hampton, VA, United States)
Norum, Tom (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 24, 2013
Publication Date
December 4, 2007
Subject Category
Acoustics
Meeting Information
Meeting: Fall Acoustics Technical Working Group
Location: Cleveland, OH
Country: United States
Start Date: December 4, 2007
End Date: December 5, 2007
Funding Number(s)
WBS: WBS 984754.02.07.07.17.03
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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