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Elliptical acoustic particle motion in underwater waveguides
David R Dall'Osto1, Peter H Dahl
1Mechanical Engineering and Applied Physics Laboratory, University of Washington, 1013 Northeast 40th Street, Seattle, Washington 98105, USA. dallosto@u.washington.edu
The Journal of the Acoustical Society of America
|July 19, 2013
Summary
This study introduces the degree of circularity to quantify elliptical particle motion in acoustic fields. This vector property shows spatial dependence, offering insights into ocean waveguides and sediment structures.
Area of Science:
- Acoustics
- Oceanography
- Geophysics
Background:
- Elliptical particle motion occurs in acoustic fields with signal interference.
- Degree of circularity quantifies this motion using particle velocity or intensity.
- This has potential applications in understanding ocean waveguides.
Purpose of the Study:
- To present a mathematical formulation for the degree of circularity.
- To demonstrate its spatial and frequency dependence using experimental data.
- To show its application in analyzing ocean environments and sediment structures.
Main Methods:
- Formulated the degree of circularity as a vector quantity.
- Utilized vector sensor measurements from laboratory experiments.
- Applied an approximate formulation to field measurements from an ocean experiment.
Main Results:
- Demonstrated depth dependence of the degree of circularity in laboratory settings.
- Showed the effect of sediment structure on range dependence of circularity in field data.
- Validated the mathematical framework for computing degree of circularity.
Conclusions:
- The degree of circularity is a fundamental vector property of acoustic fields.
- Its spatial dependence is influenced by acquisition geometry, water properties, and seabed characteristics.
- This metric aids in characterizing complex underwater acoustic environments.
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