Low and medium frequency acoustic absorption properties of acoustic metamaterials with irregular cylindrical cavities.

Abstract

The automotive industry is moving towards low noise and lightweight, and acoustic metamaterials can play a vital role. This paper presents a new acoustic metamaterial consisting of cylindrical holes of different depths arranged circumferentially and divided into different cavities by spacers. The goal is to improve the acoustic absorption performance at low and medium frequencies (f ≤ 1100 Hz). The structure was simulated and studied using the finite element (FEM) simulation software COMSOL Multiphysics to analyze the noise reduction mechanism. Simulation analysis showed that the average sound absorption coefficient is greater than 0.90 in the 510 to 970 Hz frequency range. The acoustic absorption performance of the acoustic metamaterial designed in this paper is verified by using 3D printing to produce a model and an experimental study based on impedance tubes, and the FEM simulation and experimental curves are in good agreement.