J. Rebel, V. Grützmacher, P. Neuwald, D. Ronneberger

The control of the unstable shear layer between moving and stagnant fluid is investigated in a water channel. The shear layer separating from the trailing edge of a flat splitter plate is forced by two alternative methods, namely an unsteady pressure gradient and a Tollmien-Schlichting (TS) wave excited in the boundary layer of the plate. The unsteady flow separation and the near field of the edge are of particular interest since this is the location where unwanted perturbations of the flow have to be detected and counteracted in practical applications. Large differences between the two forcing methods become obvious in the spatial distribution of the unsteady vorticity. The shear layer is excited more efficiently by the pressure gradient than by the TS wave, and some further indications hint at the dominant role of the pressure in both forcing methods. The streamwise wave number of the vorticity together with the lowest order moments of the distribution in normal direction are sufficient for the description of the potential field outside the shear layer. At the edge the streamwise development of the circulation and the deflection of an equivalent vortex sheet calculated from the first two moments depends on both the forcing method and the Strouhal number.

DGLR/AIAA 14th Aeroacoustics Conference, 1992

Conference Paper

englisch

21,0 x 29,7 cm, 9 Seiten

DGLR-Bericht, 1992, 1992-03, DGLR/AIAA 14th Aeroacoustics Conference - Proceedings; S.949-957; 1992; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroacoustics

Bibliothek

1992