Centrifugal pump impeller wheel inspired acoustic metamaterial for low frequency sound absorption

Addressing low-frequency noise is a significant concern within the realm of acoustics and noise management. Labyrinthine channel based acoustic metamaterials have been proved to control low frequency noise using local resonance effect and thermoviscous dissipations. Drawing inspiration from centrifugal pump impeller wheel, an acoustic metamaterial absorber has been devised. The design incorporates impeller vanes to create a channel with variable widths and a micro-perforate panel through which sound wave propagates to the channels. Numerical simulations using COMSOL Multiphysics and experimental analysis are conducted employing Two microphone impedance tube method. Acoustic pressure and acoustic particle velocity distribution plots from numerical simulation study are used to comprehend the sound absorption mechanism. Sound absorption coefficient results reveal that this design offers a tunable sound absorption peak in low frequency regime. Furthermore, this paper discusses the influence of various geometric parameters such as, number of vanes, panel thickness and micro-hole diameter. The subwavelength dimensions of the design contribute to noise control in machineries with space constraints.