A. Witkowska, J.G. Brasseur, D. Juve

A numerical study of the problem of sound radiation by stationary isotropic turbulence is carried out. A hybrid approach which combines a forced Direct Numerical Simulation (DNS) with Lighthills acoustic analogy is used as a computational tool. An original forcing scheme, which preserves the realistic structure of turbulence is employed. The computed acoustic power proves to be in good agreement with results obtained previously for decaying isotropic turbulence. The acoustic spectrum shows that the characteristic frequency of the generated sound is approximately four times the inverse eddy turn over time. The contributions of the different turbulence scales to the generated noise are computed separately from filtered velocity fields. For the low Reynolds number turbulence analyzed, the scales contributing mostly to noise generation are 2-3 times smaller than the energy containing scales and lie between the energy and dissipation-rate spectral peaks.

First Joint CEAS/AIAA Aeroacoustics Conference, München, 1995

Conference Paper

englisch

21,0 x 29,7 cm, 8 Seiten

DGLR-Bericht, 1995, 1995-01, First Joint CEAS/AIAA Aeroacoustics Conference - Proceedings; S.255-262; 1995; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroacoustics

Bibliothek

1995