Sound Generating Flow Structures in a Thick Orifice Plate Jet
2014 (English)In: Progress in Turbulence V: Proceedings of the iTi Conference in Turbulence 2012, Cham, Switzerland: Springer, 2014, 201-204 p.Conference paper (Refereed)
The aim of thiswork is to study sound generating flowstructures in a thickcircular orifice plate jet, placed in a circular duct. Large eddy simulations (LES)are performed for two jet Mach numbers, 0.4 and 0.9. Characteristic frequenciesin the flow, and their corresponding flow structures, are identified with dynamicmode decomposition (DMD). The results show that a tonal noise is generated atfrequencies where the jet displays strong ring vortices, in the plane wave range.The main sound generating mechanisms seems to be a fluctuating mass flow at theorifice opening and a fluctuating surface force at the plate sides, caused by the ringvortices. The frequencies are believed to be chosen, and strengthened, by a feedbackmechanism between the orifice in- and outlet.
Place, publisher, year, edition, pages
Cham, Switzerland: Springer, 2014. 201-204 p.
, Springer Proceedings in Physics, ISSN 0930-8989 ; 149
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-161903DOI: 10.1007/978-3-319-01860-7_32ScopusID: 2-s2.0-84943226056ISBN: 978-3-319-01860-7OAI: oai:DiVA.org:kth-161903DiVA: diva2:796222
5th iTi Conference in Turbulence, 2012; Bertinoro; Italy; 25 April 2012 through 25 April 2012
QC 20150330. QC 201603142015-03-182015-03-182016-09-01Bibliographically approved