Recent results are presented from several research efforts aimed at the understanding of rotorcraft blade-vortex interaction noise generation, directivity, and control. The results are based on work performed by researches at the NASA Langley Research Center, both alone and in collaboration with other research organizations. Based on analysis of a simplified physical model, the critical parameters controlling the noise generation are identified. Detailed mapping of the acoustic radiation field reveals the extreme sensitivity of directivity to rotor advance ratio and disk attitude. A means of controlling blade-vortex interaction noise by higher harmonic pitch control is discussed.
Rotorcraft blade/vortex interaction noise - Its generation, radiation, and control
ICAS Congress
1990-01-01
Conference paper
No indication
English
Reducing Blade-Vortex-Interaction Noise From Rotorcraft
Online Contents | 1996
Recent Studies of Rotorcraft Blade-Vortex Interaction Noise
Online Contents | 1994
|Rotorcraft Blade-Vortex Interaction Controller
NTRS | 1995
|