Development of new liner technology for application in hot stream areas of aero-engines
2004 (English)In: Collection of Technical Papers - 10th AIAA/CEAS Aeroacoustics Conference, 2004, 2650-2662 p.Conference paper (Refereed)
Conventional perforate acoustic liners are presently used in hot areas of aero-engines. The acoustic characteristics of these liners are extremely sensitive to flow and sound pressure level. Current liner technology regarding linear liners for engine intakes ("cold stream") does not meet the thermal and other functional requirements valid for engine exhaust areas ("hot stream"= typically 700°C). The object of the present study relates to the development of a linear liner for hot environment. It is found that a liner top sheet assembly consisting of a layer of metallic foam in combination with a perforate shows acoustic characteristics that are nearly independent of both flow and temperature. The metallic foam layer can be compressed to a predetermined degree, which is a very effective way of both increasing the acoustic resistance and lowering the non-linearity of the liner with respect to both flow and temperature variations. Varying degree of foam compression in a liner can enhance the broadband characteristics of the resulting noise reduction. This paper describes the liner development such as design, manufacturing and use of metallic foams in combination with perforate metallic sheets and the results of acoustic tests carried out in the new NLR hot stream acoustic liner test facility. The developed hot stream liner technology is suitable for application in aero-engines and is designed to give noise reduction in the order of -3dB compared to currently available technology.
Place, publisher, year, edition, pages
2004. 2650-2662 p.
Acoustic liners, Aircraft noise, Linear liners, Metallic foams, Acoustics, Attenuation, Ducts, Modulation, Noise abatement, Optimization, Pressure distribution, Sensitivity analysis, Aircraft engines
IdentifiersURN: urn:nbn:se:kth:diva-157311ScopusID: 2-s2.0-19944376165ISBN: 1563477130ISBN: 9781563477133OAI: oai:DiVA.org:kth-157311DiVA: diva2:770625
Collection of Technical Papers - 10th AIAA/CEAS Aeroacoustics Conference, 10 May 2004 through 12 May 2004, Manchester, United Kingdom
QC 201412112014-12-112014-12-082014-12-11Bibliographically approved