F. Magagnato, I. Pantle, M. Gabi

The sound emission reduction of rotating machinery such as pumps and fans is a topic of increasing importance especially with growing environmental consciousness. Any currently available prediction method is typically based on empirical or semi-empirical considerations. It is desirable to find accurate prediction methods yet in the development process, considering geometry and flow behaviour such that parameter studies can be performed without setting up expensive experiments. This paper describes a numerical prediction method of sound emission adapted to bodies in flows. It is based on unsteady flow calculations (URANS or LES) using the Ffowcs Williams and Hawkings Acoustic Analogy (FWHAA) to predict the sound field. The FWHAA is computed by extracting the relevant acoustic sources (aerodynamic, movement and replacement) out of the flow information. For demonstration the acoustic signal of a 3-dimensional unsteady flow around a circular cylinder with developed vortex street will be described. Flow calculations are performed by Large Eddy Simulation (LES). The sound signal is dominated by fluctuating forces on the cylinder surface. Also broadband noise from turbulence in the flow can be detected. The frequency spectrum at a specific observer point as well as a comparison with experimental data will be shown.

International Workshop on "LES for Acoustics"; Göttingen; 2002

Conference Paper

englisch

A4, 11 Seiten

DGLR-Bericht, 2002, 2002-03, LES for Acoustics - Proceedings; S.1-11; 2002; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

in getr. Zählung;

aeroacoustics, large eddy simulation

Bibliothek

2002