TY - GEN
T1 - A computational study of helicopter rotorwakes and noise generated during transient maneuvers
AU - Chen, Hsuan Nien
AU - Ananthan, Shreyas
AU - Leishman, Gordon
AU - Brentner, Kenneth S.
PY - 2005
Y1 - 2005
N2 - A study of three types of flight maneuvers, namely arrested descent, turns, and roll-reversal maneuvers, were examined using a rotorcraft aeroacoustics prediction model. The components of the model comprised a utility helicopter flight dynamic model, a time-accurate freevortex rotor wake model, and a maneuvering rotor noise prediction code. All rotorcraft motions and rigid body blade motions were included in the respective models. The rotor wake geometry and its development during the various flight maneuvers is described. In a transient maneuver, the rotor wake behavior is shown to be relatively complicated and in some cases the tip-vortices "bundle" together. The interaction of the tip vortices with the rotor blades creates a significant increase in levels of the impulsive noise, but primarily when the interaction of the nearly parallel to the blade. When a "bundle" of tip vortices interacts with the rotor in a near-parallel interaction, a very large increase in impulsive noise is observed over a very large region under the rotor.
AB - A study of three types of flight maneuvers, namely arrested descent, turns, and roll-reversal maneuvers, were examined using a rotorcraft aeroacoustics prediction model. The components of the model comprised a utility helicopter flight dynamic model, a time-accurate freevortex rotor wake model, and a maneuvering rotor noise prediction code. All rotorcraft motions and rigid body blade motions were included in the respective models. The rotor wake geometry and its development during the various flight maneuvers is described. In a transient maneuver, the rotor wake behavior is shown to be relatively complicated and in some cases the tip-vortices "bundle" together. The interaction of the tip vortices with the rotor blades creates a significant increase in levels of the impulsive noise, but primarily when the interaction of the nearly parallel to the blade. When a "bundle" of tip vortices interacts with the rotor in a near-parallel interaction, a very large increase in impulsive noise is observed over a very large region under the rotor.
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M3 - Conference contribution
AN - SCOPUS:84883532658
SN - 9781617829321
T3 - Annual Forum Proceedings - AHS International
SP - 37
EP - 62
BT - 61st Annual Forum Proceedings - AHS International
T2 - 61st American Helicopter Society International Annual Forum 2005
Y2 - 1 June 2005 through 3 June 2005
ER -