The use of locally resonant metamaterials to reduce flow-induced noise and vibration

Abstract

Locally resonant metamaterials (LRMs) have recently emerged and shown potential in the field of noise control engineering, given their superior noise and vibration reduction performance in tunable frequency ranges, referred to as stop bands. This paper aims to experimentally assess the potential of LRMs to suppress flow-induced noise and vibration of coupled vibro-acoustic systems such as a cavity-backed plate. At first, the vibrations of a flat plate under a turbulent flow excitation are measured and analyzed. Subsequently, different LRM solutions are designed to tackle the vibrations of the plate. In a second stage, a hard-walled backing-cavity is coupled to the system and the noise radiation due to the vibrations of the plate into the backing cavity is evaluated. The plate is then treated with the designed LRM configurations. The results show that the designed LRM solutions are able to reduce the vibrations and noise radiation of the system due to a turbulent flow excitation.