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Mach number scaling of helicopter rotor blade/vortex interaction noiseA parametric study of model helicopter rotor blade slap due to blade vortex interaction (BVI) was conducted in a 5 by 7.5-foot anechoic wind tunnel using model helicopter rotors with two, three, and four blades. The results were compared with a previously developed Mach number scaling theory. Three- and four-bladed rotor configurations were found to show very good agreement with the Mach number to the sixth power law for all conditions tested. A reduction of conditions for which BVI blade slap is detected was observed for three-bladed rotors when compared to the two-bladed baseline. The advance ratio boundaries of the four-bladed rotor exhibited an angular dependence not present for the two-bladed configuration. The upper limits for the advance ratio boundaries of the four-bladed rotors increased with increasing rotational speed.
Document ID
19870061636
Document Type
Conference Paper
Authors
Leighton, Kenneth P. (General Electric Co. Syracuse, NY, United States)
Harris, Wesley L. (MIT Cambridge, MA, United States)
Date Acquired
August 13, 2013
Publication Date
September 1, 1985
Subject Category
ACOUSTICS
Funding Number(s)
CONTRACT_GRANT: NSG-1583
Distribution Limits
Public
Copyright
Other