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The design and flight test of an engine inlet bulk acoustic linerThis paper summarizes the design, fabrication and flight evaluation of a Kevlar acoustic liner configuration for a JT15D turbofan engine. The liner was designed to suppress, by a measurable amount, a dominant (13,0) BPF tone. This tone or spinning mode was produced for research purposes by installing 41 circumferentially distributed small diameter rods upstream of the 28 fan blades. Duct liner attenuations calculated by a finite element procedure were compared to far field power (insertion) losses deduced from flight data. The finite element program modeled the variable geometry of the JT15D inlet and used a uniform flow with a boundary layer roll-off to model the inlet flow field. Calculated liner losses were generally conservative. That is, measured far field power losses were generally greater than attenuations calculated by the finite element computer program.
Document ID
19830044745
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Lester, H. C.
(NASA Langley Research Center Hampton, VA, United States)
Preisser, J. S.
(NASA Langley Research Center Hampton, VA, United States)
Parrott, T. L.
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 11, 2013
Publication Date
April 1, 1983
Subject Category
Aircraft Propulsion And Power
Report/Patent Number
AIAA PAPER 83-0781
Meeting Information
Meeting: American Institute of Aeronautics and Astronautics, Aeroacoustics Conference
Location: Atlanta, GA
Start Date: April 11, 1983
End Date: April 13, 1983
Sponsors: American Institute of Aeronautics and Astronautics
Accession Number
83A25963
Distribution Limits
Public
Copyright
Other

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