On the effect of flow direction on impedance eduction results
2016 (English)In: 22nd AIAA/CEAS Aeroacoustics Conference, 2016, 2016Conference paper (Refereed)
The last twenty years have seen a large development in inverse techniques for the determination of liner impedance under grazing flow conditions, so called impedance eduction techniques. This paper contributes to a continuing e ort to gain confidence in results obtained under different acoustical excitation configurations. Many test rigs use plane wave excitation on the upstream side of the liner for determination of liner impedance including the effect of mean flow. Some studies have compared the result for downstream acoustic excitation and found that different acoustic impedances are obtained in the two cases. It is still an open question if this result is due to the application of the Ingard-Myers boundary condition or to other errors or flaws in the measurements. This paper collects data available in the literature as well as some new data to see if the trend of obtaining di erent results for upstream and downstream excitation is persistent. The Ingard-Myers boundary condition and alternative formulations published in the literature are discussed. © 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.
Place, publisher, year, edition, pages
Aeroacoustics, Boundary conditions, Oil well casings, Acoustic excitation, Acoustical excitation, Flow direction, Grazing flows, Impedance eduction, Inverse techniques, Liner impedance, Plane wave excitation, Acoustic impedance
IdentifiersURN: urn:nbn:se:kth:diva-194608ScopusID: 2-s2.0-84982995055ISBN: 9781624103865OAI: oai:DiVA.org:kth-194608DiVA: diva2:1043885
22nd AIAA/CEAS Aeroacoustics Conference, 2016, 30 May 2016 through 1 June 2016
Conference Paper. QC 201611012016-11-012016-10-312016-11-02Bibliographically approved