Tonal noise production from a wall-mounted finite airfoil

dc.contributor.authorMoreau, D.
dc.contributor.authorDoolan, C.
dc.date.issued2016
dc.descriptionAvailable online 30 November 2015
dc.description.abstractThis study is concerned with the flow-induced noise of a smooth wall-mounted finite airfoil with flat ended tip and natural boundary layer transition. Far-field noise measurements have been taken at a single observer location and with a microphone array in the Virginia Tech Stability Wind Tunnel for a wall-mounted finite airfoil with aspect ratios of L/C=1-3, at a range of Reynolds numbers (<inf>ReC</inf>=7.9×<sup>105</sup>-1.6×<sup>106</sup>, based on chord) and geometric angles of attack (α=0-6°). At these Reynolds numbers, the wall-mounted finite airfoil produces a broadband noise contribution with a number of discrete equispaced tones at non-zero angles of attack. Spectral data are also presented for the noise produced due to three-dimensional vortex flow near the airfoil tip and wall junction to show the contributions of these flow features to airfoil noise generation. Tonal noise production is linked to the presence of a transitional flow state to the trailing edge and an accompanying region of mildly separated flow on the pressure surface. The separated flow region and tonal noise source location shift along the airfoil trailing edge towards the free-end region with increasing geometric angle of attack due to the influence of the tip flow field over the airfoil span. Tonal envelopes defining the operating conditions for tonal noise production from a wall-mounted finite airfoil are derived and show that the domain of tonal noise production differs significantly from that of a two-dimensional airfoil. Tonal noise production shifts to lower Reynolds numbers and higher geometric angles of attack as airfoil aspect ratio is reduced.
dc.description.statementofresponsibilityDanielle J. Moreau, Con J.Doolan
dc.identifier.citationJournal of Sound and Vibration, 2016; 363:199-224
dc.identifier.doi10.1016/j.jsv.2015.11.021
dc.identifier.issn0022-460X
dc.identifier.issn1095-8568
dc.identifier.urihttp://hdl.handle.net/2440/106946
dc.language.isoen
dc.publisherElsevier
dc.relation.granthttp://purl.org/au-research/grants/arc/LP110100033
dc.rights© 2015 Elsevier Ltd. All rights reserved.
dc.source.urihttps://doi.org/10.1016/j.jsv.2015.11.021
dc.titleTonal noise production from a wall-mounted finite airfoil
dc.typeJournal article
pubs.publication-statusPublished

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