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Noise due to tip vortex formation on lifting rotorsThe high frequency broadband noise radiated by the local separated flow at rotor blade tips is analyzed. The aeroacoustic model is based on the convection of the tip region's separated flow pressure fluctuations past the trailing edge of the blade. The tip vortex formation and separation are modeled from available experimental studies. The separated flow pressure fluctuations are estimated using available separated flow experimental data and correlations. The trailing edge noise was approximated using a point dipole model. The point dipole strengths were evaluated by a method based on the trailing edge noise theory of Amiet. The point dipole approach compares favorably to stationary airfoil trailing edge noise analyses and experiments except near the plane of the airfoil. The rotor tip separation noise results are compared to other noise mechanism calculations and to experiments. The tip noise mechanism is shown to be quite important in the high frequency range. It is likely to be the major contributor to high frequency broadband noise for heavily loaded rotors with low turbulence inflow.
Document ID
19800054466
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
George, A. R.
(Cornell Univ. Ithaca, NY, United States)
Najjar, F. E.
(Cornell Univ. Ithaca, NY, United States)
Kim, Y. N.
(Cornell University Ithaca, N.Y., United States)
Date Acquired
August 10, 2013
Publication Date
June 1, 1980
Subject Category
Acoustics
Report/Patent Number
AIAA PAPER 80-1010
Meeting Information
Meeting: Aeroacoustics Conference
Location: Hartford, CT
Start Date: June 4, 1980
End Date: June 6, 1980
Sponsors: American Institute of Aeronautics and Astronautics
Accession Number
80A38636
Distribution Limits
Public
Copyright
Other

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