A numerically stable T-matrix method for acoustic scattering by nonspherical particles with large aspect ratios and...

Area of Science:

• Acoustics
• Computational Physics
• Numerical Analysis

Background:

• Accurate computation of acoustic scattering T-matrices is crucial for understanding wave interactions with particles.
• Existing methods face limitations with nonspherical particles and high size parameters, impacting numerical stability.
• The two-part method offers a potential solution by reformulating the scattering problem.

Purpose of the Study:

• To demonstrate the numerical stability and physical correctness of the two-part method for acoustic scattering T-matrix computation.
• To evaluate the method's performance for nonspherical particles with large aspect ratios and size parameters.
• To validate the efficacy of the two-part method at the limits of current numerical stability.

Main Methods:

• A two-part computational approach was employed, involving far-field computation and T-matrix calculation via spherical Fourier transform.
• The method avoids explicit computation of Hankel functions by focusing on far-field data, enhancing stability.
• Numerical experiments were conducted using the open-source TMATROM3 software package.

Main Results:

• The two-part method demonstrated robust numerical stability and physical correctness for challenging scattering scenarios.
• The elimination of Hankel functions was confirmed as a key factor in the method's enhanced stability.
• Successful application to nonspherical particles with large aspect ratios and size parameters was achieved.

Conclusions:

• The two-part method provides a numerically stable and physically accurate approach for computing acoustic scattering T-matrices.
• This method extends the capability to handle complex particle geometries and large size parameters beyond current limitations.
• The open-source TMATROM3 package facilitates the practical application of this advanced computational technique.