@article {Sturm:2012:0736-2501:699,
title = "Tonal fan noise of an isolated axial fan rotor due to inhomogeneous coherent structures at the intake",
journal = "Noise Control Engineering Journal",
parent_itemid = "infobike://ince/ncej",
publishercode ="ince",
year = "2012",
volume = "60",
number = "6",
publication date ="2012-11-01T00:00:00",
pages = "699-706",
itemtype = "ARTICLE",
issn = "0736-2501",
url = "https://ince.publisher.ingentaconnect.com/content/ince/ncej/2012/00000060/00000006/art00005",
doi = "doi:10.3397/1.3701041",
keyword = "21.6.3, 11.4.1",
author = "Sturm, Michael and Carolus, Thomas",
abstract = "In spite of low circumferential Mach number and no obvious disturbances up- and downstream, the sound of axial fans is often dominated by distinctive tones at blade passing frequency (BPF) and its higher harmonics. Flow visualization at the air intake and a correlation analysis of measured
blade pressure fluctuations reveal that quasi-stationary coherent structures exist in the inflow which may act as a source of the tones. They can partly be suppressed by a hemispherical inflow control device which supports this finding.",
}