Vibro-Acoustic Analysis of Rectangular Plate-Cavity Parallelepiped Coupling System Embedded with 2D Acoustic Black Holes

Abstract

An acoustic black hole (ABH) has the ability to concentrate and manipulate flexural waves, which can be used for structural vibration suppression and noise attenuation. In this paper, a 2D ABH rectangular plate is designed and a 2D ABH plate-cavity coupling system is constructed using the 2D ABH plate and five rectangular elastic plates of uniform thickness. Series of vibro-acoustic FEM models of the plate-cavity parallelepiped coupling system embedded with 2D ABHs are established, and the vibro-acoustic coupling simulation is conducted to analyze the effects of ABHs on the coupling modes, vibro-acoustic coupling characteristics, and mechanism of ABHs and the damping layer. It is shown that at most frequencies in the range of 3600~5000 Hz, the damping 2D ABH plate-cavity parallelepiped coupling system can significantly suppress the sound pressure and greatly reduce the peak values. It is also found that the significant reduction of the participation factor of the acoustic modes within the 100th order is the main mechanism for the obvious suppression of the sound pressure in the damping ABH plate-cavity coupling system at 3701 Hz. Finally, an experimental platform of vibro-acoustic measurement of the 2D ABH coupling system is constructed, and the accuracy of the vibro-acoustic FEM models of the 2D ABH coupling systems established in this paper and the numerical simulation calculation are verified by the vibro-acoustic measurement experiment.

Improving Low-Frequency Panel Absorbers with Two-Dimensional Acoustic Black Hole

“…It is also possible to extend the power-law profile to generate two-dimensional tapered indentations, which are also referred to as 2D ABH in circular [13,14] or elliptical forms [15]. Coupled systems consisting of ABH embedded panels and air back cavities have recently been studied numerically and experimentally [16][17][18]. ABH has been successfully applied for vibration and noise reduction in structures [19,20].…”