Scattering from a finite cylinder near an interface

Area of Science:

• Computational Acoustics
• Wave Scattering Phenomena
• Numerical Methods in Physics

Background:

• Acoustic scattering from objects near interfaces is crucial in many physical scenarios.
• Existing methods often struggle with non-axisymmetric geometries and multiple interactions.
• Accurate modeling of finite cylinders near pressure release surfaces presents a significant challenge.

Purpose of the Study:

• To develop and describe a Boundary Integral Equation Method (BIEM) for computing scattering from a finite cylinder near a pressure release interface.
• To address the complexities introduced by the cylinder's orientation (parallel or tilted) relative to the interface, breaking azimuthal symmetry.
• To accurately account for multiple interactions between the scattered field and the interface.

Main Methods:

• Utilized a Boundary Integral Equation Method (BIEM) for scattering computations.
• Employed an azimuthal-conversion matrix to manage multiple interactions between the scattered field and the interface.
• Benchmarked the BIEM against wavefield superposition for a sphere near a pressure-release surface.

Main Results:

• Computed scattered spectra for finite cylinders (parallel and tilted) and various source/receiver configurations.
• Quantified the differences between single-scatter solutions and fully coupled solutions including multiple target/interface interactions.
• Numerically examined and discussed the issue of irregular frequencies in both single-scatter and fully coupled BIEM.

Conclusions:

• The developed BIEM effectively computes acoustic scattering from finite cylinders near pressure release interfaces, even with broken azimuthal symmetry.
• Accounting for multiple target/interface interactions significantly impacts scattering predictions compared to single-scatter approximations.
• The study provides a robust numerical framework for analyzing complex scattering problems and addresses the challenge of irregular frequencies.