Preliminary investigation of the effect of surface fluctuations on sound amplitude in guide mode propagation.

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.

Department dc:contributor.department

Engineering Acoustics

Grantor dc:publisher

Monterey, California ; Naval Postgraduate School

Year dc:date.issued

1970

Author dc:creator

• Jordan, Wesley Earl Jr.

Advisor dc:contributor.advisor

• Coppens, Alan B.

Statement dc: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.

Language dc:language.iso

en_US

Handle dc:identifier.uri

https://hdl.handle.net/10945/15132

OAI identifier oai:identifier

oai:calhoun.nps.edu:10945/15132