@article {Abshagen:2018:0736-2935:587,
title = "Noise induced in a cylindrical towed model from separated/reattached turbulent flows",
journal = "INTER-NOISE and NOISE-CON Congress and Conference Proceedings",
parent_itemid = "infobike://ince/incecp",
publishercode ="ince",
year = "2018",
volume = "257",
number = "1",
publication date ="2018-12-01T00:00:00",
pages = "587-596",
itemtype = "ARTICLE",
issn = "0736-2935",
url = "https://ince.publisher.ingentaconnect.com/content/ince/incecp/2018/00000257/00000001/art00059",
keyword = "underwater application, separated/reattached turbulent boundary layer, elastic tube, flow induced noise",
author = "Abshagen, Jan and Nejedl, Volkmar",
abstract = "Results from an underwater experiment on turbulent flow-induced noise in the interior of a cylindrical towed model are presented. The thin axisymmetric model consist of an elastic hose filled with a fluid and the towing experiments were performed under sea conditions at three different
towing velocity U = 2.5, 3.3, and 4.2 m s-1 (flow velocities U' = 2.0, 2.7, and 3.6 m s-1) at a towing depth of about 10 m. During a tow the elastic hose is excited from an axisymmetric turbulent boundary layer flow that has reattached after being triggered upstream at axisymmetric obstacle
due to flow separation. Turbulent flow-induced noise in the (quiescent) interior of the model is measured with a hydrophone array located on the axis of symmetry and analyzed by wavenumber-frequency analysis. By scaling with outer variables (model diameter d, fluid density, flow velocity U')
the power spectral densities of flow-induced noise collapse onto each and decay according to an f-3 law (at low U' between f-2 and f-3) below a corner frequency of about 150 Hz. In this regime (interior) noise is governed by properties of the (outer) turbulent boundary layer. Above the corner
frequency a substantial drop in spectral level is observed going along with an incomplete collapse of the scaled power spectral densities.",
}