Static and flyover noise measurements of an inverted profile exhaust jetTests using a TF30 mixed flow afterburning turbofan engine in an F-111 airplane were conducted to study the noise characteristics of an inverted velocity profile jet. Full-authority digital engine control allowed the inverted profile jet to be compared to a uniform jet of equal thrust statically and in flight. An exhaust velocity survey showed that the ratio of the outer to inner stream velocities was 1.37; therefore, only small noise reductions were expected. At static conditions, the inverted profile jet was approximately 3 decibels quieter than the uniform jet at peak noise angles. During a flyover it was approximately 1 decibel quieter.
Document ID
19770045740
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Burcham, F. W., Jr. (NASA Hugh L. Dryden Flight Research Center Edwards, CA, United States)
Lasagna, P. L. (NASA Hugh L. Dryden Flight Research Center Edwards, CA, United States)
Kurtenbach, F. J. (NASA Flight Research Center Edwards, Calif., United States)
Date Acquired
August 8, 2013
Publication Date
March 1, 1977
Subject Category
Aircraft Propulsion And Power
Report/Patent Number
ASME PAPER 77-GT-81
Meeting Information
Meeting: Gas Turbine Conference and Products Show
Location: Philadelphia, PA
Start Date: March 27, 1977
End Date: March 31, 1977
Sponsors: American Society of Mechanical Engineers