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Effects of vane/blade ratio and spacing on fan noiseThe effects of vane/blade ratio and spacing on fan noise are investigated to develop a fan noise prediction scheme which is calibrated against experimental data. A 44 blade, 0.504 diameter fan is used to demonstrate the production of fan noise data free from excess noise caused by rotor turbulence interaction. Two stator sets consisting of a cut-off set with 86 vanes, and a cut-on set of 48 vanes are used, with a total range of spacing from 0.5 to 2.3 rotor chords. The model includes viscous wake interaction noise and the potential field interactions of both the rotor and stator. A free-field acoustic environment is achieved by covering the walls, ceiling and floor with 0.7 m polyurethane foam wedges, providing less than + or - 1 dB standing wave ratio at 200 Hz. Only a 3 dB drop in tone level occurs as the spacing is increased from 0.5 to 2.3 rotor chords, and results indicate that the rotor wakes impinging on the stator vanes are the principal noise source for subsonic rotor speeds.
Document ID
19820026922
Document Type
Conference Paper
Authors
Kantola, R. A.
(General Electric Co., Power Generation Group, Lynn MA, United States)
Gliebe, P. R.
(General Electric Co., Aircraft Engine Group, Cincinnati OH, United States)
Date Acquired
August 10, 2013
Publication Date
October 1, 1981
Subject Category
Aircraft Propulsion And Power
Report/Patent Number
AIAA PAPER 81-2033
Meeting Information
Aeroacoustics Conference(Palo Alto, CA)
Funding Number(s)
CONTRACT_GRANT: NAS3-22062
Distribution Limits
Public
Copyright
Other
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