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Optimization and Control of Acoustic Liner Impedance with Bias FlowBecause communities are impacted by steady increases in aircraft traffic, aircraft noise continues to be a growing problem for the growth of commercial aviation. Research has focused on improving the design of specific high noise source areas of aircraft and on noise control measures to alleviate noise radiated from aircraft to the surrounding environment. Engine duct liners have long been a principal means of attenuating engine noise. The ability to control in-situ the acoustic impedance of a liner would provide a valuable tool to improve the performance of liners. The acoustic impedance of a liner is directly related to the sound absorption qualities of that liner. Increased attenuation rates, the ability to change liner acoustic impedance to match various operating conditions, or the ability to tune a liner to more precisely match design impedance represent some ways that in-situ impedance control could be useful. With this in mind, the research to be investigated will focus on improvements in the ability to control liner impedance using a mean flow through the liner which is referred to as bias flow.
Document ID
20000088637
Acquisition Source
Langley Research Center
Document Type
Other
Authors
Wood, Houston (Virginia Univ. Charlottesville, VA United States)
Follet, Jesse (Virginia Univ. Charlottesville, VA United States)
Date Acquired
September 7, 2013
Publication Date
August 4, 2000
Subject Category
Acoustics
Funding Number(s)
CONTRACT_GRANT: NCC1-340
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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