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Multielement suppressor nozzles for thrust augmentation systems.The noise reduction and nozzle performance characteristics of large-scale, high-aspect-ratio multielement nozzle arrays operated at low velocities were determined by test. The nozzles are selected for application to high-aspect-ratio augmentor suppressors to be used for augmentor wing airplanes. Significant improvements in noise characteristics for multielement nozzles over those of round or high-aspect-ratio slot nozzles are obtained. Elliptical noise patterns typical of slot nozzles are presented for high-aspect-ratio multielement nozzle arrays. Additional advantages are available in OASPL noise reduction from the element size and spacing. Augmentor-suppressor systems can be designed for maximum beam pattern directivity and frequency spectrum shaping advantages. Measurements of the nozzle wakes show a correlation with noise level data and frequency spectrum peaks. The noise and jet wake results are compared with existing prediction procedures based on empirical jet flow equations, Lighthill relationships, Strouhal number, and empirical shock-induced screech noise effects.
Document ID
19720033222
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Lawrence, R. L.
O'Keefe, J. V.
Tate, R. B.
(Boeing Co. Seattle, Wash., United States)
Date Acquired
August 6, 2013
Publication Date
January 1, 1972
Subject Category
Aircraft
Report/Patent Number
AIAA PAPER 72-131
Meeting Information
Meeting: American Institute of Aeronautics and Astronautics, Aerospace Sciences Meeting
Location: San Diego, CA
Start Date: January 17, 1972
End Date: January 19, 1972
Sponsors: Science Research Council
Accession Number
72A16888
Funding Number(s)
CONTRACT_GRANT: NAS2-6344
CONTRACT_GRANT: NASA TASK I
Distribution Limits
Public
Copyright
Other

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