Accession Number : AD1026729


Title :   Low Frequency Acoustic Intensity Propagation Modeling in Shallow Water Waveguides


Descriptive Note : Technical Report


Corporate Author : Naval Postgraduate School Monterey United States


Personal Author(s) : Moss,Geoffrey R


Full Text : http://www.dtic.mil/dtic/tr/fulltext/u2/1026729.pdf


Report Date : 01 Jun 2016


Pagination or Media Count : 77


Abstract : Three popular numerical techniques are employed to examine the acoustic pressure and intensity features present in several environments of interest. Free field propagation and analytically tractable planar interfacial two-fluid transmission and reflection are used to benchmark the commercial software package COMSOL. Canonical Pekeris-type waveguides are used as initial points of comparison to illustrate COMSOLs ability to capture all pertinent physics. Additional environments with non-trivial bathymetry and varying sound speed profiles are then used to examine the rich feature set anticipated in experimental data. Predictions of recently estimated and experimentally verified physical phenomena serve as further proof of the accuracy of implementation of the Finite Element Method. Guidelines and recommendations are provided for future studies using COMSOL along with circumstances under which traditional treatment of the air-water interface is appropriate and when an explicit full-physics model is required.


Descriptors :   wave propagation , underwater acoustics , transmission loss , near field , acoustic waveguides , acoustic properties , shallow water , helmholtz equations , differential equations , acoustic waves , acoustic propagation , FINITE ELEMENT ANALYSIS , waveguides , low frequency


Subject Categories : Acoustics
      Electrical and Electronic Equipment


Distribution Statement : APPROVED FOR PUBLIC RELEASE