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Acoustic and aerodynamic study of a pusher-propeller aircraft modelAn aerodynamic and acoustic study was made of a pusher-propeller aircraft model in the NASA-Ames 7 x 10 ft Wind Tunnel. The test section was changed to operate as an open jet. The 591 mm diameter unswept propeller was operated alone and in the wake of three empennages: an I tail, Y tail, and a V tail. The radiated noise and detailed wake properties were measured. Results indicate that the unsteady blade loading caused by the blade interactions with the wake mean velocity distribution had a strong effect on the harmonics of blade passage noise. The blade passage harmonics above the first were substantially increased in all horizontal directions by the empennage/propeller interaction. Directivity in the plane of the propeller was maximum perpendicular to the blade surface. Increasing the tail loading caused the propeller harmonics to increase 3 to 5 dB for an empennage/propeller spacing of 0.38 mean empennage chords. The interaction noise became weak as empennage propeller spacing was increased beyond 1.0 mean empennage chord lengths. Unlike the mean wake deficit, the wake turbulence had only a small effect on the propeller noise, that effect being a small increase in the broadband noise.
Document ID
19910012515
Acquisition Source
Legacy CDMS
Document Type
Technical Publication (TP)
Authors
Soderman, Paul T.
(NASA Ames Research Center Moffett Field, CA, United States)
Horne, W. Clifton
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
September 6, 2013
Publication Date
September 1, 1990
Subject Category
Acoustics
Report/Patent Number
A-89038
NASA-TP-3040
NAS 1.60:3040
Accession Number
91N21828
Funding Number(s)
PROJECT: RTOP 505-61-11
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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