Sound propagation through a variable area duct - Experiment and theoryA comparison of experiment and theory has been made for the propagation of sound through a variable area axisymmetric duct with zero mean flow. Measurement of the acoustic pressure field on both sides of the constricted test section was resolved on a modal basis for various spinning mode sources. Transmitted and reflected modal amplitudes and phase angles were compared with finite element computations. Good agreement between experiment and computation was obtained over a wide range of frequencies and modal transmission variations. The study suggests that modal transmission through a variable area duct is governed by the throat modal cut-off ratio.
Document ID
19810065342
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Silcox, R. J. (NASA Langley Research Center Hampton, VA, United States)
Lester, H. C. (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 11, 2013
Publication Date
October 1, 1981
Subject Category
Acoustics
Report/Patent Number
AIAA PAPER 81-1967
Meeting Information
Meeting: Aeroacoustics Conference
Location: Palo Alto, CA
Start Date: October 5, 1981
End Date: October 7, 1981
Sponsors: American Institute of Aeronautics and Astronautics