NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Sound radiation from single and annular stream nozzles, with modal decomposition of in-duct acoustic powerAn experimental program was carried out to study the acoustic characteristics of single and annular stream duct-nozzle systems at various flow conditions by using a refined acoustic impulse technique. In this technique, signal synthesis and signal averaging processes are incorporated to generate a desired impulsive signal from acoustic driver(s) and to eliminate background noise (flow noise) from in-duct and far field signals, respectively. The contribution of higher order modes to incident reflected and transmitted acoustic powers is accounted for by using a modal decomposition process. The annular stream terminations were tested statically at various annular stream flow velocities with no inner stream flow. The results derived from the experiments include in-duct acoustic powers, termination reflection coefficients, transmission coefficients, far field power, and acoustic dissipation.
Document ID
19870050355
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Salikuddin, M.
(Lockheed-Georgia Co. Marietta, United States)
Date Acquired
August 13, 2013
Publication Date
March 22, 1987
Publication Information
Publication: Journal of Sound and Vibration
Volume: 113
ISSN: 0022-460X
Subject Category
Acoustics
Accession Number
87A37629
Funding Number(s)
CONTRACT_GRANT: NAS3-20797
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available