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Optics and AcousticsAcoustics

Experimental Testing of the Variable Rotated Elastic Parabolic Equation

Authors: Harry J Simpson; Jon M Collis; Raymond J Soukup; Michael D Collins; William L Siegmann; NAVAL RESEARCH LAB WASHINGTON DC PHYSICAL ACOUSTICS BRANCH
Abstract:
A series of laboratory experiments was conducted to obtain high-quality data for acoustic propagation in shallow water waveguides with sloping elastic bottoms. Accurate modeling of transmission loss in these waveguides can be performed with the variable rotated parabolic equation method. Results from an earlier experiment with a flat or sloped slab of polyvinyl chloride (PVC) demonstrated the necessity of accounting for elasticity in the bottom and the ability of the model to produce benchmark-quality agreement with experimental data [J. M. Collis et al., J. Acoust. Soc. Am. 122, 1987 1993 (2007)]. This paper presents results of a second experiment, using two PVC slabs joined at an angle to create a waveguide with variable bottom slope. Acoustic transmissions over the 100 300 kHz band were received on synthetic horizontal arrays for two source positions. The PVC slabs were oriented to produce three different simulated waveguides: flat bottom followed by downslope, upslope followed by flat bottom, and upslope followed by downslope. Parabolic equation solutions for treating variable slopes are benchmarked against the data.

Limitations: APPROVED FOR PUBLIC RELEASE
Description: Journal article
Pages: 7
Report Date: Nov 2011
Report Number: A918255
Keywords relating to this report:
ACCURACY
ACOUSTIC PROPERTIES
ANGLES
CHLORIDES
ELASTIC PROPERTIES
EQUATIONS
EXPERIMENTAL DATA
HORIZONTAL ORIENTATION
LOSSES
MODELS
OCEAN BOTTOM
PARABOLAS
REPRINTS
SIMULATION
SLOPE
SOLUTIONS(GENERAL)
SOUND TRANSMISSION
SOURCES
VARIABLES
WATER
WAVEGUIDES
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