A perfectly matched layer formulation for modeling transient wave propagation in an unbounded fluid-solid medium.

Area of Science:

• Computational physics
• Wave propagation modeling
• Numerical methods

Background:

• Simulating wave propagation in infinite media often uses perfectly matched layers (PML).
• Heterogeneous media with both solid and fluid components present challenges for existing PML formulations, especially at solid-fluid interfaces.
• Applications in marine seismology and biomedical ultrasound require accurate modeling of these coupled systems.

Purpose of the Study:

• To present a novel second-order time-domain PML formulation for two-dimensional fluid-solid heterogeneous media.
• To ensure the PML satisfies interface coupling boundary conditions throughout the computational domain.
• To validate the formulation's accuracy and stability in discrete settings.

Main Methods:

• Developed a second-order time-domain PML formulation for 2D fluid-solid media.
• Incorporated interface coupling boundary conditions.
• Conducted numerical simulations to assess performance.

Main Results:

• The proposed PML formulation effectively handles wave propagation in heterogeneous fluid-solid media.
• Numerical results demonstrate accuracy and stability without spurious reflections.
• The PML successfully absorbs bulk, surface, and evanescent waves.

Conclusions:

• The new PML formulation provides an accurate and stable solution for modeling wave propagation in complex fluid-solid environments.
• This method is applicable to critical fields such as marine seismology and biomedical ultrasound.
• The formulation addresses limitations of previous PML models for coupled solid-fluid problems.