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On the Comparison of the Long Penetration Mode (LPM) Supersonic Counterflowing Jet to the Supersonic Screech JetThe authors provide a brief overview of the classic tonal screech noise problem created by underexpanded supersonic jets, briefly describing the fluid dynamic-acoustics feedback mechanism that has been long established as the basis for this well-known aeroacoustics problem. This is followed by a description of the Long Penetration Mode (LPM) supersonic underexpanded counterflowing jet phenomenon which has been demonstrated in several wind tunnel tests and modeled in several computational fluid dynamics (CFD) simulations. The authors provide evidence from test and CFD analysis of LPM that indicates that acoustics feedback and fluid interaction seen in LPM are analogous to the aeroacoustics interactions seen in screech jets. Finally, the authors propose applying certain methodologies to LPM which have been developed and successfully demonstrated in the study of screech jets and mechanically induced excitation in fluid oscillators for decades. The authors conclude that the large body of work done on jet screech, other aeroacoustic phenomena, and fluid oscillators can have direct application to the study and applications of LPM counterflowing supersonic cold flow jets.
Document ID
20150016244
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Farr, Rebecca A. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Chang, Chau-Lyan. (NASA Langley Research Center Hampton, VA, United States)
Jones, Jess H. (AI Signal Research, Inc. Huntsville, AL, United States)
Dougherty, N. Sam (Engineering Research and Consulting, Inc. Huntsville, AL, United States)
Date Acquired
August 21, 2015
Publication Date
June 22, 2015
Subject Category
Acoustics
Report/Patent Number
M15-4529
Meeting Information
Meeting: AIAA/CEAS Aeroacoustics Conference/AIAA Aviation and Aeronautics Forum and Exposition 2015
Location: Dallas, TX
Country: United States
Start Date: June 22, 2015
End Date: June 26, 2015
Sponsors: American Inst. of Aeronautics and Astronautics, Council of European Aerospace Societies
Distribution Limits
Public
Copyright
Public Use Permitted.

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