Folding Cavity Acoustic Liner For Combustion Noise Reduction

Yu, Jia; Chien, Eugene

doi:10.2514/6.2006-2681

Cited by 11 publications

(3 citation statements)

References 2 publications

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“…This allows for mitigation of noise in the 400-630Hz target range in which combustion noise typically falls. This design showed a 3 to 4dB reduction in combustor noise at approach [29]. A weight penalty is applied with the noise reduction to account for the mass of the liner.…”

Section: Combustor Plug Linermentioning

confidence: 99%

“…The addition of acoustic liners allows viscous dissipation of the pressure waves reducing the noise. The Goodrich Aerostructure Group developed an acoustic liner for a hot nozzle plug using a folding cavity Helmholtz resonator concept to comply with the space constraint [29]. The low frequency noise produced by the combustor would require a large chamber for a conventional Helmholtz resonator design.…”

Section: Combustor Plug Linermentioning

confidence: 99%

See 1 more Smart Citation

Noise Assessment of NASA Environmentally Responsible Aviation (ERA) Technologies and Concepts

Jiménez

Pfaender

Havrilesko

et al. 2012

12th AIAA Aviation Technology, Integration, and Operations (ATIO) Conference and 14th AIAA/ISSMO Multidisciplinary Analysis And

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We present a comprehensive assessment of NASA Environmentally Responsible Aviation Project technologies across aircraft component, single event, and multi-event levels. Modeling capabilities appropriate for each level of abstraction are introduced. We examine noise technologies in terms of component-level performance effects, modeling considerations, and aircraft-level impacts. Single event performance results include discussion of reference vehicle models and their accuracy, as well as modeled vehicle performance in the form of noise certification point measurements and single event contours. We then present an assessment of the technology portfolio in the context of a generic airport multi-event study where the noise performance of industry project aircraft expected to enter the market over the next decade is also approximated. Results discussed provide a comprehensive characterization of noise reductions achievable with technologies in question and provide further analytical support for their continued development.

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Section: Combustor Plug Linermentioning

confidence: 99%

Section: Combustor Plug Linermentioning

confidence: 99%

Noise Assessment of NASA Environmentally Responsible Aviation (ERA) Technologies and Concepts

Jiménez

Pfaender

Havrilesko

et al. 2012

12th AIAA Aviation Technology, Integration, and Operations (ATIO) Conference and 14th AIAA/ISSMO Multidisciplinary Analysis And

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“…Recent developments try to address a larger frequency range by combining cells of different volumes in one single structure [11,12]. By placing larger and smaller cells next to each other and folding the cavities for the larger cells, the effective damping range can be increased with only moderate increase in overall liner-depth [10,25]. A virtual increase of cell depth is also used in the special acoustic absorber concept aiming to address multiple frequencies with a special emphasis on the low-frequency region [19].…”

Section: Introductionmentioning

confidence: 99%

Novel liner concepts

Bake

Knobloch

2019

CEAS Aeronaut J

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Modern, low emission aero-engine concepts like for instance Ultra-High-Bypass-Ratio (UHBR) designs claim higher demands on the damping performance of acoustic wall treatment, called liner, installed in the engine. New liner concepts are needed providing a more broadband damping efficiency ranging explicitly to the low frequency range. However, space and weight constrains are still also one of the crucial criteria which need to be fulfilled by the liner structure. To overcome this challenge two novel liner concepts are presented here. One concept, the hybrid ZML, combines the classical Single-Degree-Of-Freedom (SDOF) liner with a Zero-Massflow-Liner (ZML) principle. The other one, the FlexiS concept, takes advantage of the intrinsic material damping of flexible walls within the liner structure. A proof of concepts study of both novel concepts is provided highlighting the enhanced damping performance with respect to broadband capacity and low frequency damping.

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