P.A. Vitsas, P. Menounou

Helicopter rotor Blade Wake Interaction (BWI) noise is known to be significant during take-off and level flight. Less attention has been given to descent flight conditions, where Blade Vortex Interaction (BVI) noise is dominant. The present study investigates BWI noise in descent flight conditions by analyzing acoustic and aerodynamic data from the HELISHAPE test. It is shown that BWI fluctuations (of both acoustic and blade pressure waveforms) can be categorized in two types with respect to their origin: one type is associated with impulsive BVI, while the other with blade turbulence interaction. The statistical and spectral properties of these fluctuations reinforce theories that relate BWI noise to coherent eddies present in the flow. Further, the location of the interacting vortices reveals that younger vortices do not contribute to BWI noise levels. Finally, it is shown that the blade tip shape does not significantly affect BWI noise.

35th European Rotorcraft Forum 2009,

Conference Paper

englisch

21,0 x 29,7 cm, 11 Seiten

DGLR-Bericht, 2009, 2009-03, 35th European Rotorcraft Forum 2009 - Conference Proceedings; S.1-11; 2009; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

in getr. Zählung;

rotor blades, rotorcrafts, blade vortex interaction, blade wake interaction

Bestellbar

2009