Regression analysis of the geometric properties and sound absorption characteristics of micro-slit periodic structures

In recent years, acoustic metamaterials utilizing subwavelength-scale microperiodic structures have gained significant attention for their ability to control sound wave behavior. By designing unit cell geometries, these structures have the potential to serve as novel sound-absorbing materials with desired acoustic properties. However, this research field remains in its early stages, and the detailed relationship between geometry and sound absorption characteristics has yet to be fully understood. This study aims to systematically investigate this relationship by focusing on a simple cubic lattice structure featuring a wall on the incident side with embedded micro-slits. First, numerical simulations were conducted to calculate transport parameters and sound absorption coefficients for a wide range of microperiodic structures with varying geometric conditions. Subsequently, regression analysis was performed, particularly focusing on the airflow resistivity, to elucidate the correlation between geometric properties and acoustic performance. A highly accurate regression model was obtained, suggesting that the desired airflow resistivity, and consequently the sound absorption characteristics, can be achieved through appropriate slit geometry.