Accession Number : ADA188504

Title :   The Temporal and Spatial Acoustical Response of a Point-Driven Fluid-Loaded Plate.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Stevens, James G

PDF Url : ADA188504

Report Date : Mar 1987

Pagination or Media Count : 125

Abstract : The radiated acoustic field from a point-driven, fluid-loaded plate was determined several years ago. However, current operational problems force a reexamination in the light of certain acoustic anomalies. The types of waves that propagate in a solid plate are reviewed for their relative importance. Experimental models were constructed in an anechoic acoustic tank in an attempt to model the aforementioned anomalies. It is found that the effect of the plexiglass plate placed at the boundary of a method of images geometry is that of a phase delay only. Therefore, mode conversion from compressional waves to flexural waves is thought to be insignificant. A second experiment is described in which a plexiglass plate was driven with a small longitudinal vibrator. Experimental radiation patterns suggest that of a quasi-piston. Plexiglass is an acoustically slow media, therefore the coincidence effect is not possible. Further, its absorption of acoustic waves make it poor choice for experiments where wave propagation is important.

Descriptors :   *RADIATION, *UNDERWATER ACOUSTICS, ACOUSTIC COATINGS, ACOUSTIC WAVES, ACOUSTICS, ANOMALIES, COINCIDENCE COUNTING, DELAY, EXPERIMENTAL DESIGN, FLEXURAL PROPERTIES, GEOMETRY, IMAGES, RADIATED NOISE, RADIATION PATTERNS, SPATIAL DISTRIBUTION, THESES, VIBRATORS(MECHANICAL), WAVE PROPAGATION, WAVES

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE