The prediction of rotor rotational noise using measured fluctuating blade loadsIn tests conducted at the NASA Langley Research Center Helicopter Rotor Test Facility, simultaneous measurements of the high-frequency fluctuating aerodynamic blade loads and far-field radiated noise were made on a full-scale, nontranslating rotor system. After their characteristics were determined, the measured blade loads were used in an existing theory to predict the far-field rotational noise. A comparison of the calculated and measured rotational noise is presented with specific attention given to the effect of blade loading coefficients, chordwise loading distributions, blade loading phases, and observer azimuthal position on the predictions.
Document ID
19740053865
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Hosier, R. N. (U.S. Army, Air Mobility Research and Development Laboratory, Hampton Va., United States)
Pegg, R. J. (NASA Langley Research Center Hampton, Va., United States)