Abstract
In order to apply acoustic energy to industrial fields, its amplification is essential and vibroacoustic coupling is one of best ways of amplifying acoustic energy. The present paper describes vibroacoustic coupling between the plate vibrations and the internal sound fields of a cylindrical structure connected two cylinders with thin plates, and the coupling phenomena are investigated theoretically and experimentally by considering the behavior of the plates and the acoustic characteristics of the internal sound fields with variations in the cylinder length, when an external harmonic force is applied to one end plate. The acoustic characteristics are evaluated based on the sound pressure level, which is maximized while changing the phase difference between the plate vibrations. The behavior of the plate vibration is investigated by varying the phase difference with the cylinder length. Moreover, the experiment of electricity generation is carried out with piezoelectric elements, which are installed on the plates. These results reveal that vibroacoustic coupling is effective in increasing the acoustic energy and can extract the acoustic energy via the plate vibrations.
