The influence of the inlet duct contour on forward radiated fan noiseMeasurements have been obtained to determine the extent to which the shape of the inlet duct affects the directivity pattern of forward radiated noise from aircraft gas turbine engines. The test program was conducted using a model fan to which were attached any of three inlet ducts with each designed to cause a particular noise directivity pattern. Existing information on the effects of wave refraction in inlet-type flow fields was used to design the duct contours. Results indicated that the shape of the inlet duct strongly influenced the radiated noise field but that wave refraction was not the dominant factor in controlling the noise directivity pattern.
Document ID
19770068256
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Sloan, D. (Boeing Commercial Airplane Co. Seattle, WA, United States)
Farquhar, B. W. (Boeing Commercial Airplane Co. Seattle, WA, United States)
Rayl, C. (Boeing Commercial Airplane Co. Seattle, Wash., United States)
Date Acquired
August 9, 2013
Publication Date
October 1, 1977
Subject Category
Acoustics
Report/Patent Number
AIAA PAPER 77-1355
Meeting Information
Meeting: Aeroacoustics Conference
Location: Atlanta, GA
Start Date: October 3, 1977
End Date: October 5, 1977
Sponsors: American Institute of Aeronautics and Astronautics