Smart Panel Technology for Broadband Noise Reduction

초록

Smart panel is a panel that is utilized a passive material at high frequencies and piezoelectric shunt damping at low frequencies. For investigating the noise reductionperformance, three configurations of panels are tested: single panel, single panel with sound absorbing material and double panel. The single panel consists of a host plate structure on which four piezoelectric patches are bonded and electrical shunt circuits are connected independently. The parameters for resonant shunt circuit are determined by maximizing the dissipated energy through the circuit. The transmitted noise of smart panels is measured at an acoustic tunnel. Sound absorbing material and air gap reduces the sound transmitted at the mid-frequency region effectively while the use of piezoelectric shunt damping works at resonance frequencies of the panel structure. As a result, a remarkable noise reduction of 15dB was achieved in a broadband frequency region. The double panel exhibits better noise reduction than other panels. This approach was also applied to the structural acoustic problem of turbulent boundary layer (TBL) induced sound radiated from a panel, and results are discussed.