A computationally efficient finite element model with perfectly matched layers applied to scattering from axially...

Area of Science:

• Computational acoustics
• Numerical methods in fluid dynamics

Background:

• Accurate computation of acoustic radiation and scattering is crucial for understanding fluid-structure interactions.
• Existing numerical methods often face challenges with computational efficiency and boundary condition implementation for fluid-loaded structures.

Purpose of the Study:

• To present a frequency-domain finite-element (FE) technique for computing acoustic radiation and scattering from axially symmetric fluid-loaded structures.
• To incorporate the Berenger perfectly matched layer (PML) for efficient emulation of radiation conditions.
• To simplify meshing for broadband frequency analysis and provide discretization guidelines.

Main Methods:

• Developed a frequency-domain finite-element (FE) technique.
• Applied the Berenger perfectly matched layer (PML) directly at the fluid-structure interface.
• Utilized wavelength-dependent rescaling of PML coordinates for broadband analysis.
• Derived quantitative geometry discretization guidelines based on structural wavelengths.

Main Results:

• The FE-PML technique accurately computes acoustic radiation and scattering from fluid-loaded structures.
• The method effectively emulates the Sommerfeld radiation condition with minimal mesh size.
• Simplified meshing and discretization guidelines were established for low to mid frequencies.
• The technique demonstrated applicability in layered fluid media and showed close agreement with analytical and validated numerical solutions.

Conclusions:

• The proposed frequency-domain FE-PML technique offers an efficient and accurate solution for acoustic radiation and scattering problems.
• The method is versatile, applicable to various fluid environments including layered media.
• The findings provide a valuable tool for analyzing complex underwater acoustics and structural acoustics problems.