P.L. Lavrich, J.C. Simonich, D.C. McCormick, D. Parzych

An experimental study was performed to measure the vortical wakes from Propfan configurations run with both aft swept and forward swept blading. A comparison of the wake structure was made between the two configurations at three loading conditions. Flow visualization indicated a leading edge vortex exists on the aft swept blading which had previously been identified as a nominant interaction noise mechanism. In contrast, the forward swept blading exhibited a leading edge flow separation which did not form a vortex. Differences in the tip vortex structure were exhibited and were attributed to the presence or absence of a leading edge vortex. The tip vortex of the forward swept blade had much less core velocity deficit than the aft swept wake. It was observed that the forward swept configuration requires additional blade sweep at the leading edge to induce a leading edge vortex. Despite the lack of a leading edge vortex, an estimate of the interaction noise for a counter-rotating configuration did not indicate a noise reduction with the forward swept configuration with suction surface separation. Blade sweep at the leading edge would have to be increased from the (rather mild) sweep of the current configuration to have the potential to reduce interaction noise.

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.898-906; 1992; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroacoustics, propellers

Bibliothek

1992