Broadband Noise Control in Ducts via Electro-Mechanical Coupling

Previous studies have shown that a light but stiff plate covering a side-branch rigid cavity may work effectively as a duct noise control device over a wide range of low to medium frequencies. In this study, a passive shunt circuit is introduced to the plate to further enhance the noise reduction performance, which leads to a 'smart plate silencer'. Owing to the electro-mechanical coupling between the electric circuit and the piezo-electro materials, the structural properties of the smart plate vary greatly with frequency. Results show that breakthrough enhancement of the noise control device may be achieved with a proper choice of the shunt circuit.