Inertial effects on single-perforation plates resistivity at high flow rates: Computational fluid dynamics and...

Area of Science:

• Acoustics
• Fluid Dynamics
• Materials Science

Background:

• Airflow resistivity is a key parameter in acoustic materials.
• Understanding viscous and inertial effects is crucial for predicting material performance.
• Periodic arrays of perforated plates are used in various acoustic applications.

Purpose of the Study:

• To investigate the viscous and inertial effects on airflow resistivity in periodic arrays of single-perforation plates.
• To provide insights into material losses and acoustic behavior under varying sound excitation levels.
• To determine global and local airflow resistivity coefficients.

Main Methods:

• Computational Fluid Dynamics (CFD) was used to predict material pressure drop.
• Flow rate and pore Reynolds numbers (0.3–1500) were analyzed.
• Static airflow resistivity and Forchheimer coefficients were determined globally and locally.

Main Results:

• CFD predictions showed good agreement with experimental measurements across the studied Reynolds numbers.
• Viscous effects were found to be constant throughout the material.
• Inertial effects were observed to be dominated by the first plate at higher pore Reynolds numbers.

Conclusions:

• Local inertial effects are critical for accurate acoustic modeling of these materials, particularly under high sound excitation.
• The study provides a method for determining both viscous and inertial contributions to airflow resistivity.
• Findings enhance the understanding of sound absorption mechanisms in perforated plate structures.