Impedance-matched absorbers for finite-difference parabolic equation algorithms

Area of Science:

• Computational physics
• Acoustics
• Wave propagation

Background:

• The perfectly matched layer (PML) is a novel concept for absorbing boundary conditions.
• Traditional absorbing layer methods often suffer from spurious reflections.
• Acoustic parabolic equations (PEs) are widely used for modeling wave propagation.

Purpose of the Study:

• To adapt the perfectly matched layer (PML) absorber for acoustic parabolic equations (PEs).
• To reduce spurious reflections in acoustic wave propagation simulations.
• To enable more efficient computational modeling by reducing boundary point requirements.

Main Methods:

• Incorporation of an imaginary component into the transverse coordinate of the computational grid.
• Adaptation of the PML absorber, originally developed for electromagnetic waves, for acoustic applications.
• Utilizing higher-order propagator approximations in conjunction with the PML absorber.

Main Results:

• The adapted PML absorber effectively eliminates spurious reflections in acoustic PE simulations.
• The impedance-matched layer significantly outperforms physical absorbing layer methods.
• Reduced computational grid sizes are feasible due to the efficient reflection absorption.

Conclusions:

• The PML absorber is a highly effective technique for mitigating reflections in acoustic parabolic equation models.
• This adaptation offers a more efficient and accurate approach to acoustic wave propagation simulations.
• The method holds significant potential for advancing computational acoustics and related fields.