Development of an Acoustic Metamaterials for Aero Acoustic Noise Control

Abstract

This paper aims at proposing a novel type tunable acoustic metamaterials with complete band gap composed of piezoelectric rods (Lithium Niobate) with square array as inclusion embedded polyimide aerogel background. The plane wave expansion method and the principles of Bloch-Floquet method used to get a band frequency and study the pass band for noise control. The results of this paper provide the required guidance for designing tunable wave filters or wave guide which might be useful in high-precision mechanical systems operated in certain frequency ranges, and switches made of piezoelectric; they also propose a novel type of tunable mechanical meta composite, where is independent of wave direction and has an equal sensitivity in all directions in which reacts omnidirectional and improves the aero acoustic noise control (e.g. bladeless fans) as well as general performance of vibrating structures (e.g. wind turbine).

Keywords

• Phononic crystal; Acoustic band gaps; Passive control; Piezoelectricity; Low frequency regime shielding.