K.-J. Schultz, W.R. Splettstösser

A wind tunnel study was performed to investigate the noise characteristics and directivity pattern of a 40% scaled helicopter rotor system (BO 105 main/tail rotor model). The major objectives of the study were to estabJ i sh the importance of the tail rotor with respect to the overall noise radiation and to determine the noise reduction potential of aerodynamically improved blade design. The results show that under descent flight condition, where strong main rotor blade-vortex interact ion occurs, the tail rotor contribution is of secondary order, while at climb condition the tail rotor dominates the noise radiation over a significant range of noise emission angles. Main-/tail-rotor aerodynamic interference noise does not appear to be a prime contributor to the total noise emission. The acoustic benefit from fully utilizing the potential of aerodynamically improved blade design was determined: maintaining rotor thrust while reducing the tip speed of such blades by 10% yielded noise reductions on the order of 3 to 4 dB and in certain directions in excess of 7 to 8 dB.

DGLR/AIAA 14th Aeroacoustics Conference, 1992

Conference Paper

englisch

21,0 x 29,7 cm, 11 Seiten

DGLR-Bericht, 1992, 1992-03, DGLR/AIAA 14th Aeroacoustics Conference - Proceedings; S.123-133; 1992; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroacoustics, bo 105 helicopter

Bibliothek

1992