A. Frendi, L. Maestrello, A. Bayliss

The coupling between a two-dimensional, supersonic, laminar boundary layer and a flexible surface is studied using direct numerical computations of the Navier-Stokes equations coupled with the nonlinear plate equation. Two dimensional disturbances of Tollmien-Schlichting type are introduced into the boundary layer at the inflow boundary. If the surface is assumed rigid these disturbances grow and then decay as predicted by linear stability theory. When the surface is assumed to be flexible and these waves provide the only forcing, there is virtually no difference in disturbance growth between a rigid and flexible surface. However, when the surface is forced to vibrate by a combination of Tollmien-Schlichting and plane acoustic waves, the amplitudes of the disturbances are found to increase over the flexible surface. However, since the boundary layer is stable the disturbances decay downstream of the flexible surface. Numerical experiments are also carried out using the plane acoustic waves alone with a constant sound pressure level and variable frequency. The results show that decreasing the frequency of the acoustic waves results in higher growth of the disturbance over the flexible surface.

DGLR/AIAA 14th Aeroacoustics Conference, 1992

Conference Paper

englisch

21,0 x 29,7 cm, 10 Seiten

DGLR-Bericht, 1992, 1992-03, DGLR/AIAA 14th Aeroacoustics Conference - Proceedings; S.46-55; 1992; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

subsonic flow, aeroacoustics, boundary layers, laminar flow, Navier-Stokes equation

Bibliothek

1992