A.T. Fedorchenko

A general two-medium theory of aerodynamic sound has been created. This non-linear theory is based on the original decomposition of all five independent scalar variables of a high-unsteady flow into acoustic and non-acoustic components, and a special integro-differential operator has been designed to implement this. The absence of an adequate algorithm for such a decomposition was the most feeble point of all the "conventional" approaches to the theory of aerodynamic sound sources. The general concept of such a decomposition is considered within an initial-boundary-value problem posed for a flow of inviscid gas. The Galilean invariant non-local formulae are derived for sound sources in the equation system which governs the acoustic field. Some general problems of computational aeroacoustics are discussed, including those which take place within LES approach. The key questions are emphasized in specifying the most complex boundary conditions, and new non-local procedures of boundary control are suggested. In the practical aspect the primary attention is focused on the study of the key mechanisms of sound generation in high-unsteady subsonic flows, both internal and free, acoustic feedback and self-excited resonance effects in ducts with separated flows, non-linear interaction between small-scale turbulence and large-scale vortical motion in jets and mixing layers, etc. Diverse two-dimensional flows were investigated to obtain the computational and analytic solutions with using the new theory of aerodynamic sound.

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

Conference Paper

englisch

A4, 12 Seiten

DGLR-Bericht, 2002, 2002-03, LES for Acoustics - Proceedings; S.1-12; 2002; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

in getr. Zählung;

aeroacoustics, large eddy simulation

Bibliothek

2002