Low-Frequency Acoustic Radiation from Free-Flooded Ring Transducers Driven through the Circumference, Thickness, or Height

Abstract

The normal velocity distribution of the surface of a free-flooded ring transducer completely determines its radiation characteristics in a given medium. The SHIP program is an algorithm for rapidly predicting the radiation characteristics of a free-flooded ring when the known surface velocity distribution is axisymmetric. The character of the radiation at low frequencies is extremely sensitive to the details of the velocity distribution which, in turn, depends not only on the geometry of the ring, but also on the manner in which the ring is driven and on the electromechanical parameters of the ring material. Gross differences in the directivity patterns predicted for different drive conditions occur at frequencies well below the first radial resonance for typical rings. Directivity patterns were obtained for a number of rings fabricated for different commonly encountered drive conditions (circumference, thickness, or height) and compared with patterns predicted by the SHIP program using simple models for the velocity distribution appropriate to each drive. Good agreement was obtained between the measured and predicted directivity patterns.

Research and Fabrication of Broadband Ring Flextensional Underwater Transducer

“…The frequency decrease of the first vibration mode is attributed to the effect of the diameter of the PZT ring on the frequency of the breathing mode of the PZT ring. The greater the diameter, the lower the frequency for the resonance frequency of first vibration mode [17][18][19]. The reason for the frequency decrease of the second vibration mode is an increase in the diameter of the metal shells with an increase in the diameter of the PZT ring.…”

“…Sensors 2021, 21, 1548 5 of 14 of first vibration mode [17][18][19]. The reason for the frequency decrease of the second vibration mode is an increase in the diameter of the metal shells with an increase in the diameter of the PZT ring.…”