Theory and Numerical Modeling of Low-Frequency Acoustic Scattering from Bubble Plumes Near the Sea Surface
Abstract
From a theoretical foundation in boundary integral equations, we develop and implement a general method for computing the complex acoustic scattering amplitudes of bubble plumes near the sea surface. The implementation, named BIRPS (Boundary Integral Resonant Plume Scatter) incorporates surface- image and resonance effects, and allows user-specified plume shapes, interior sound speed functions, and depths. Simulations with model intermediate plumes reveal multiple sub-kHz resonant features. The resonance spectrum depends mainly on the plume's size, shape, and mean sound speed. The Q of a resonance depends on these parameters and on the sound speed gradient. Resonant scattering responses have a nonquadratic depth dependence and an elevation dependence whose complexity and frequency sensitivity increase with frequency. BIRPS may be joined with a continuous wave (CW) propagation model to provide scattering simulations or with a multifrequency driver to generate reverberation predictions. our results provide a theoretical/modeling component for the investigation of surface reverberation and are relevant to problems of resonant scattering from complex bodies in general.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 18, 1992
- Accession Number
- ADA259199
Entities
People
- D. Wurmser
- R. F. Gragg
Organizations
- United States Naval Research Laboratory