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A comparison of broadband models for sand sediments
1Mathematics Department, United States Naval Academy, Annapolis, Maryland 21402, USA.
The Journal of the Acoustical Society of America
|January 18, 2007
Summary
The Chotiros-Isakson model improves predictions of sediment acoustic properties compared to older models. An alternative air bubble resonance model shows promise but faces theoretical challenges.
Area of Science:
- Acoustics
- Geophysics
- Materials Science
Background:
- The Biot-Stoll model is a standard for acoustic wave propagation in porous media.
- Existing models struggle to accurately predict compressional wave speed and attenuation in sediments.
- The Chotiros-Isakson model offers an improved approach by considering pore fluid compressibility.
Purpose of the Study:
- To evaluate the Chotiros-Isakson model's performance against experimental data.
- To explore an alternative model based on air bubble resonance.
- To assess the physical plausibility of the air bubble resonance model.
Main Methods:
- Utilized the Nelder-Mead simplex method for parameter optimization.
- Compared model predictions with existing experimental measurements of wave speed and attenuation.
- Applied Rayleigh-Plesset theory to analyze bubble oscillation dynamics.
Main Results:
- The Chotiros-Isakson model demonstrates significantly better agreement with experimental data than conventional models.
- At least two sets of Chotiros-Isakson parameters yield good agreement with measurements.
- The air bubble resonance model performs comparably to the Chotiros-Isakson model but has theoretical limitations.
Conclusions:
- The Chotiros-Isakson model provides a more accurate framework for sediment acoustics.
- The presence of air bubbles is a key factor influencing sediment acoustic properties.
- The air bubble resonance model, while predictive, may not be universally applicable due to theoretical constraints on bubble behavior.
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