K. Knowles, D. Bray, M.J. Wilson

The flowfield surrounding single and twin jets impinging in a cross-flow has been investigated experimentally. Two regions of the flowfield are seen to be particularly unsteady: the ground vortex formed by separation of the wall jet in the cross-flow; and the fountain formed between two adjacent impinging jets. The ground vortex formed by twin (side-byside) impinging jets is found to be even more unsteady than that due to a single jet. The unsteadiness has been quantified by ground plane pressure measurements. These have shown the fluctuations to be broadband in nature but with a low frequency hump. This confirms results from elsewhere using low speed jets. The present work also suggests that the peak amplitudes in ground Plane pressure fluctuations occur either side of the vortex. There is, as yet, no evidence that the vortex fluctuations are fed by impinging jet instabilities. Nor does nozzle pressure ratio seem to have a direct effect on the spectrum of fluctuations.

DGLR/AIAA 14th Aeroacoustics Conference, 1992

Conference Paper

englisch

21,0 x 29,7 cm, 8 Seiten

DGLR-Bericht, 1992, 1992-03, DGLR/AIAA 14th Aeroacoustics Conference - Proceedings; S.882-889; 1992; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroacoustics

Bibliothek

1992