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Noise of a simulated installed model counterrotation propeller at angle-of-attack and takeoff/approach conditionsTwo modern high-speed advanced counterrotation propellers, F7/A7 and F7/A3 were tested in the NASA Lewis Research Center's 9- by 15-Foot Anechoic Wind Tunnel at simulated takeoff/approach conditions of 0.2 Mach. Both rotors were of similar diameter on the F7/A7 propeller, while the aft diameter of the F7/A3 propeller was 85 percent of the forward propeller to reduce tip vortex-aft rotor interaction. The two propellers were designed for similar performance. The propellers were tested in both the baseline configuration and installed configuration consisting of a simulated upstream nacelle support pylon and fuselage section. Acoustic measurements were made with a polar microphone probe which recorded sideline directivities at various azimuthal locations. Aerodynamic measurements were also made to establish propeller operating conditions. The propellers were run at initial blade setting angles adjusted to achieve equal forward/aft torque ratios at angle of attack with the pylon and fuselage simulation in place. Data are presented for propeller operation at 80 and 90 percent of design speed (the forward rotor design tip speed was 238 m/sec (780 ft/sec). Both propellers were tested at the maximum rotor-rotor spacing of 14.99 cm (5.90 in.) based on the pitch change axis separation.
Document ID
19900011478
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Woodward, Richard P. (NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1990
Subject Category
Acoustics
Report/Patent Number
AIAA PAPER 90-0283
NASA-TM-102440
E-5210
NAS 1.15:102440
Meeting Information
Meeting: Aerospace Sciences Meeting
Location: Reno, NV
Country: United States
Start Date: January 8, 1990
End Date: January 11, 1990
Sponsors: AIAA
Accession Number
90N20794
Funding Number(s)
PROJECT: RTOP 535-03-01
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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