Blade/vortex interactions and noise abatement techniques during descent
Abstract
Investigations conducted to obtain a fundamental understanding of the impulsive blade slap noise characteristic of helicopters in descent and to recommend noise abatement procedures are described. The aerodynamic modeling utilized is outlined; the acoustic pressure formulation is shown; the correction of ground reflection effects is summarized; and the model verification is described. Boundary mapping and noise level variability results which provide guidance for slap noise reduction are discussed.
- Publication:
-
European Rotorcraft Forum
- Pub Date:
- September 1985
- Bibcode:
- 1985erf..rept.....P
- Keywords:
-
- Blade Slap Noise;
- Blade-Vortex Interaction;
- Descent;
- Helicopters;
- Noise Reduction;
- Rotor Blades;
- Sound Pressure;
- Wave Reflection;
- Acoustics