The prediction of helicopter rotor discrete frequency noiseAn accurate prediction of the noise produced by helicopters requires a good understanding of the noise generating mechanisms involved. Such an understanding can lead to controlling the noise of existing helicopters by avoiding noisy regimes of flight or by redesigning the main and tail rotors. The present investigation is concerned with approaches which are suitable for the calculation of discrete frequency noise of helicopter rotors. The governing differential equation of acoustics used in a consideration of acoustic formulations is the Ffowcs Williams-Hawkings (FW-H) equation. Attention is given to a method reported by Farassat (1981), a method developed by Succi (1979), and a procedure discussed by Woan and Gregorek (1978).
Document ID
19820057018
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Farassat, F. (NASA Langley Research Center Hampton, VA, United States)
Succi, G. P. (Bolt Beranek and Newman, Inc. Cambridge, MA, United States)