An improved design of Helmholtz resonator for acoustic energy harvesting devices

Abstract

Helmholtz resonator (HR) is the key element of acoustic energy harvesting devices. It is used to augment or attenuate the incoming acoustic wave. In acoustic energy harvesters the objective of HR is to augment the incoming acoustic wave. In this work an improved architecture of HR is proposed for acoustic energy harvesting devices. Modeling and simulation of the HR is reported. The HR is modeled as one degree of freedom system. The proposed HR has a high pressure gain as compared to the HR used in previously developed acoustic energy harvesting devices. The proposed design for HR results in high acoustic stiffness of the air entrapped inside the Helmholtz cavity that ultimately improves the pressure gain of the HR. Moreover, for similar dimensions the resonant frequency of the proposed HR is 1693 Hz, while resonant frequency of the reported HRs is 1119.7 Hz. Furthermore, at resonance the pressure gain of the proposed HR is 56.5 dB which is quite high than the pressure gain of the reported HRs with cylindrical shape cavities that is 52.7 dB.