This paper studies the state of knowledge and the needed improvement in noise methodology and measurements for tilt rotor aircraft. Similarities and differences between tilt rotor aeroacoustic conditions and helicopter and propeller experience are identified. A discussion of the possible principal noise mechanisms throughout the flight envelope shows a need for further experimental and analytical investigations to develop an adequate understanding of the important sources and influencing factors. Existing experimental data from flight tests suggest terminal area noise reduction by operating within certain portions of the conversion flight envelope. Prediction methods are found to provide approximate indications only for low frequency harmonic and broadband noise for several of the tilt rotor's operating conditions. The acoustic effects of the hover case 'fountain' flow are pronounced and need further research. Impulsive noise and high frequency harmonic noise remain problems, as on helicopters, pending major improvements in wake, unsteady aerodynamics, and acoustics methodology.
Tilt rotor aircraft aeroacoustics
1989-05-01
Conference paper
No indication
English
Tilt rotor broadband hover aeroacoustics
Tema Archive | 1993
|Aerodynamics and Aeroacoustics of Helicopters and Tilt Rotor Aircraft
British Library Conference Proceedings | 1993
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