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TITLE AND SUBTITLE:
Some Acoustic Results from the Pratt and Whitney Advanced Ducted Propulsor - Fan 1
AUTHOR(S):
Dittmar, James, H.; Elliot, David, M.; Bock, Lawrence, A.
REPORT DATE:
1999-03-01
FUNDING NUMBERS:
WU-538-03-11-00
PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES):
National Aeronautics and Space Administration John H. Glenn Research Center at Lewis Field Cleveland, Ohio 44135-3191
PERFORMING ORGANIZATION REPORT NUMBER:
E-11582
SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES):
National Aeronautics and Space Administration Washington, DC 20546-0001
REPORT TYPE AND DATES COVERED:
Technical Memorandum
SPONSORING/MONITORING AGENCY REPORT NUMBER:
NASA/TM-1999-209049
SUPPLEMENTARY NOTES:
James H. Dittmar and David M. Elliot, NASA Glenn Research Center; and Lawrence A. Bock, United Technologies Corporation, Pratt & Whitney, East Hartford, CT. Responsible person, James H. Dittmar, organization code 5940, (216) 433-3291.
ABSTRACT:
Noise measurements were obtained for the Advanced Ducted Propulsor (ADP) - Fan 1, with and without nacelle acoustic treatment. The fan was tested with no acoustic treatment (hard wall) and with acoustic treatment installed in three configurations in the nacelle (mid, mid plus aft, fully treated). The hard wall results showed that the radiated noise from the fan came primarily from the aft end of the nacelle. At takeoff and higher speeds, the noise measured at the inlet angles was also found to be dominated by noise from the aft end. Significant amounts of attenuation were observed with acoustic treatment installed and comparison with predictions showed the treatment save more attenuation than predicted. Effective Perceived Noise Levels were determined for a large hypothetical 4 engine airplane. These levels showed that the installed acoustic treatment provided as much as 5 EPNdB of noise reduction. A traverse with a probe having three microphones, one above the other, showed azimuthal variations in the noise that need to be further investigated.
SUBJECT TERMS:
Ducted propulsor noise; Fan Noise
NUMBER OF PAGES:
86
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