Computational analysis of the influence of the perforated plate on sandwich transducer in sound radiation performance

Abstract

To improve the acoustic radiation performance of the sandwich transducer, a perforated plate is added to the radiation end of the transducer. The improved effect of the addition of a perforated plate on acoustic radiation performance of the transducer is studied. First, based on electromechanical equivalence principle, when a perforated plate is attached to a piston vibrator, the expressions of the vibration velocity of radiation surfaces, directivity index (DI) and radiated sound power are derived. Thus, the influences of the perforated plate on the sound radiation performance of the piston vibrator are analyzed. Then, the perforated plate is attached to the radiation surface of a sandwich transducer, and the electromechanical equivalent circuit of the transducer is established. Thus, the input impedance at the radiation end, vibration velocity and sound pressure level (SPL) of the transducer are derived. Further, the SPL of the transducer is calculated and the influences of the perforated plate on the transducer acoustic radiation performance with or without a matching layer are studied. And, the influences of the perforated plate on acoustic radiation performance of different operating frequency transducers are analyzed. Finally, the influences of the perforated plate structural parameters on the SPL of transducer are studied. The results show that the perforated plate with appropriate parameters could further improve the impedance matching between the input impedance and the radiation impedance at the radiation end of the transducer, thus the radiated SPL could be improved maximally. The research method is expected to applied in high-power transducer design.