Change search
ReferencesLink to record
Permanent link

Direct link
Determination of liner impedance under high temperature and grazing flow conditions
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. KTH, School of Industrial Engineering and Management (ITM), Centres, Competence Center for Gas Exchange (CCGEx). (MWL)
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. (MWL)ORCID iD: 0000-0002-8474-8563
2014 (English)In: 20th AIAA/CEAS Aeroacoustics Conference, 2014Conference paper (Refereed)
Abstract [en]

Acoustic liners have traditionally been used to reduce fan noise from the aircraft engine intake. To increase noise reduction there are now plans to also put liners in hot stream parts of the engine. In order to test liners under as realistic conditions as possible there has been a large development in inverse techniques for determination of liner impedance under grazing flow conditions, so called impedance eduction techniques. Testing under hot stream conditions has received smaller attention. This paper discusses techniques for measuring liner impedance under hot stream conditions and present some results obtained for single degree of freedom Helmholtz resonator liners with different configurations. It could be argued that the main effect of high temperatures is a change of medium properties such as: density, viscosity and speed of sound. If this is true the high temperature impedance could be predicted by scaling from the result at cold conditions. This is investigated in the paper by comparing measured results from liner impedance models available in the literature.

Place, publisher, year, edition, pages
Keyword [en]
Acoustic impedance, Aeroacoustics, Aircraft engines, Noise abatement, Helmholtz resonators, High temperature, Impedance eduction, Inverse techniques, Measured results, Realistic conditions, Single degree of freedoms, Stream condition, Acoustic noise
National Category
Aerospace Engineering
URN: urn:nbn:se:kth:diva-167578ScopusID: 2-s2.0-84903888324ISBN: 9781624102851OAI: diva2:815883
20th AIAA/CEAS Aeroacoustics Conference 2014, 16 June 2014 through 20 June 2014, Atlanta, GA

QC 20150602

Available from: 2015-06-02 Created: 2015-05-22 Last updated: 2015-06-02Bibliographically approved

Open Access in DiVA

No full text


Search in DiVA

By author/editor
Kabral, RaimoBodén, Hans
By organisation
Aeronautical and Vehicle EngineeringCompetence Center for Gas Exchange (CCGEx)Linné Flow Center, FLOW
Aerospace Engineering

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 78 hits
ReferencesLink to record
Permanent link

Direct link