Effects of ingested atmospheric turbulence on measured tail rotor acousticsResults from an outdoor hover test of a full-scale Lynx tail rotor are presented. The investigation was designed to further the understanding of the acoustics of an isolated tail rotor hovering out-of-ground effect in atmospheric turbulence, without the effects of the main rotor wake or other helicopter components. Measurements include simultaneous rotor performance, noise, inflow, and far-field atmospheric turbulence. Results with grid-generated inflow turbulence are also presented. The effects of turbulence ingestion on rotor noise are quantified. Turbulence ingestion noise is found to be the dominant noise mechanism at locations near the rotor axis. At these locations, the sound radiated by the hovering rotor increases with both increasing atmospheric wind speed and ingested rms turbulent velocity.
Document ID
19930051967
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Signor, David B. (NASA Ames Research Center Moffett Field, CA, United States)
Yamauchi, Gloria K. (NASA Ames Research Center Moffett Field, CA, United States)
Mosher, Marianne (NASA Ames Research Center Moffett Field, CA, United States)
Hagen, Martin J. (California Polytechnic State Univ. San Luis Obispo, United States)
George, Albert R. (Cornell Univ. Ithaca, NY, United States)