Accession Number : AD0717582

Title :   Preliminary Investigation of the Effect of Surface Fluctuations on Sound Amplitude in Guided Mode Propagation.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF

Personal Author(s) : Jordan,Wesley Earl , Jr

Report Date : DEC 1970

Pagination or Media Count : 108

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 the 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. (Author)

Descriptors :   (*SOUND, PROPAGATION), (*WATER WAVES, SURFACE ROUGHNESS), FREQUENCY, MATHEMATICAL MODELS, THESES

Subject Categories : Acoustics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE