Noise Attenuation by Helmholtz Resonators Attached to a Duct

Abstract

The resonating frequency and the transmission loss due to two 1-DOF cylindrical Helmholtz resonator attached to a duct is thoroughly investigated in this literature to attenuate low frequency noise using finite element method. Primarily, the relative spacing between the two identical resonators attached to a duct is investigated in this study to find the optimum positions between the resonators. The investigation is further carried out by changing the dimensions of the cavity and neck for the optimum relative position .Finally, based on these several investigations, a conclusion is drawn for an optimized system of two identical 1-DOF Helmholtz resonators in terms of position, orientation and geometry. The results shows a significant improvement in noise reduction compared to a single 1-DOF Helmholtz resonator .The results of a single 1-DOF Helmholtz resonator of a published literature were also validated both analytically and numerically in this study.