Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

AK: Akustik

AK 5: Thermo- und Strömungsakustik (Sitzungsorganisation: Martin Ochmann und Rafael Piscoya, Berlin)

AK 5.7: Hauptvortrag

Dienstag, 8. März 2005, 15:00–15:30, TU EB222

An evaluation of coupling techniques for combined LES/LEE approaches to calculate aerodynamically generated noise — •Wim De Roeck, Gustavo Rubio, Yves Reymen, Martine Baelmans und Wim Desmet — K.U. Leuven, Dept. Mech. Eng., Celestijnenlaan 300B, 3001 Leuven

Due to the large disparity between the energy scales of the acoustic and flow variables, the direct solution of the compressible Navier-Stokes equations for computational aeroacoustics (CAA) is only possible for a limited number of applications. Therefore hybrid methods are proposed, in which, the computational domain is split into a source region and an acoustic propagation region. This paper evaluates the most commonly used techniques to couple both regions. A first class of methods uses equivalent sources: source terms based on turbulent velocities (Lighthill), vorticity (Möhring), pressure fluctuations (Hardin and Pope) and wall pressures (Curle) are used. The other class of methods is based on acoustic pressure boundary conditions on a surface, surrounding the dominant aeroacoustic sources. The different coupling techniques will be compared and validated for a cavity flow noise application, where the source region is calculated with large-eddy simulation (LES) and linearized Euler equations (LEE) are used as propagation equations. In this way, this paper aims at giving more insight in the accuracy and practical use of different hybrid CAA prediction techniques.