The Acoustics of Multiphase Materials in the Shallow Water Ocean Environment

date March 29, 2013
comments no comments.

Friday, March 29, 2013 4:00 p.m. in ETC 4.150

Professor Preston S. Wilson
Applied Research Laboratories
Department of Mechanical Engineering
The University of Texas at Austin
http://www.arlut.utexas.edu/

The shallow water ocean environment can be quite complicated acoustically, in part due to the abundance of multiphase materials, such as air bubbles in water near the ocean surface, water‑saturated granular sediments, gas-bearing sediments and gas-bearing vegetation on the ocean bottom, and swim bladder fish in the water column.  Successful operation of sonar in this environment requires knowledge of the acoustic properties of these materials.  The basic physics of sound propagation in these materials will be discussed and results from a variety of laboratory and field experiments will be presented.  The success and failure of various models that attempt to predict the acoustic behavior of these materials will also be discussed.  Finally, a proof-of-concept sonar system will be described that exploits the nonlinear acoustic properties of bubbly liquids to distinguish bubble clouds from more rigid targets. [Work supported by ONR and ARL:UT IR&D.]