Preliminary investigation of the effect of surface fluctuations on sound amplitude in guide mode propagation.
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Authors
Jordan, Wesley Earl Jr.
Subjects
propagation
normal mode
irregular boundary
amplitude fluctuation
surface waves
normal mode
irregular boundary
amplitude fluctuation
surface waves
Advisors
Coppens, Alan B.
Date of Issue
1970-12
Date
December 1970
Publisher
Monterey, California ; Naval Postgraduate School
Language
en_US
Abstract
A simple theoretical relation between a one- dimensional surface
wave and the amplitude fluctuations of an acoustic standing
wave in a cavity with idealized boundaries is presented. An experiment
was designed to investigate the applicability of the
theory to a more complicated configuration. A 237 cm x 117 cm
x 9 cm water-filled cavity with pressure-release walls was excited
in a normal mode by a source placed in one corner. The resulting
acoustic signal was monitored at various locations throughout the
cavity with a small probe receiver. Wind-driven surface waves
were generated by a multi-fan blower placed at one end of the
cavity. The relationship between the resulting fluctuation of this
acoustic signal and the surface fluctuation above the receiver was
investigated. The results are consistent with the simple theory
at low surface-wave frequencies. Anomalous behavior was observed
for the higher frequencies of the surface wave spectrum. Possible
mechanisms for this inconsistency are postulated and discussed.
Type
Thesis
Description
Series/Report No
Department
Engineering Acoustics
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.