Results of the initial phase of a research project to study the design constraints on helicopter noise are presented. These include the calculation of nonimpulsive rotor harmonic and broadband hover noise spectra, over a wide range of rotor design variables and the sensitivity of perceived noise level (PNL) to changes in rotor design parameters. The prediction methodology used correlated well with measured whirl tower data. Application of the predictions to variations in rotor design showed tip speed and thrust as having the most effect on changing PNL.
Design of helicopter rotors to noise constraints
1978-08-01
Aufsatz (Konferenz)
Keine Angabe
Englisch
High-speed noise of helicopter rotors
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|Jet-propelled helicopter rotors
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|Thickness noise of helicopter rotors at high tip speeds
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|Thickness Noise of Helicopter Rotors a High Tip Speeds
NTIS | 2004
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