Class IV Flextensional Transducer with a reflector

Interest in underwater transducers has persisted since the mid-1900s. Underwater transducers are designed in various shapes using various materials depending on the purpose of use, such as to achieve high power, improve broadband, and enhance beam steering. Therefore, in this study, an analysis is conducted according to the structural shape of the transducer, exterior material, and active material. By classifying transducers by structure, the transducer design trends and possible design issues can be identified. Researchers have constantly attempted new methods to improve the performance of transducers. In addition, a methodology to overcome this problem is presented. Finally, this review covers old and new research, and will serve as a reference for designers of underwater transducer.

Section: Flextensional Transducermentioning

confidence: 99%

Section: Figurementioning

confidence: 99%

Design of Piezoelectric Acoustic Transducers for Underwater Applications

Pyun

Kim

Park

2023

“…The previous sections analyze the effects of changes in the parameters of the transducer on resonance frequency and transmitting voltage response, so as to achieve the operation of bandwidth and TVR. However, in underwater acoustic communication or underwater detection, sometimes in order to avoid interference of multipath, the transducer will have directionally radiating capability [20,21], such as "Cardioid" directivity, which can be formed by superposition of one omnidirectional sound source and one sound source with the dipole radiation characteristic [22][23][24][25], as shown in Figure 8. This section elaborates on the principle of the flextensional transducer made of PZT rings and metal shells to radiate sound wave directionally.…”

Section: Synthetic Directivitymentioning

confidence: 99%

“…Sensors 2021, 21, 1548 2 of 14 with a resonance frequency of 600 Hz, the output acoustic power of which is 10 kW. However, its -3 dB bandwidth is 160 Hz [9].…”

Section: Introductionmentioning

confidence: 99%

Research and Fabrication of Broadband Ring Flextensional Underwater Transducer

Hong

et al. 2021

At present, high-speed underwater acoustic communication requires underwater transducers with the characteristics of low frequency and broadband. The low-frequency transducers also are expected to be low-frequency directional for realization of point-to-point communication. In order to achieve the above targets, this paper proposes a new type of flextensional transducer which is constructed of double mosaic piezoelectric ceramic rings and spherical cap metal shells. The transducer realizes broadband transmission by means of the coupling between radial vibration of the piezoelectric rings and high-order flexural vibration of the spherical cap metal shells. The low-frequency directional transmission of the transducer is realized by using excitation signals with different amplitude and phase on two mosaic piezoelectric rings. The relationship between transmitting voltage response (TVR), resonance frequency and structural parameters of the transducer is analyzed by finite element software COMSOL. The broadband performance of the transducer is also optimized. On this basis, the low-frequency directivity of the transducer is further analyzed and the ratio of the excitation signals of the two piezoelectric rings is obtained. Finally, a prototype of the broadband ring flextensional underwater transducer is fabricated according to the results of simulation. The electroacoustic performance of the transducer is tested in an anechoic water tank. Experimental results show that the maximum TVR of the transducer is 147.2 dB and the operation bandwidth is 1.5–4 kHz, which means that the transducer has good low-frequency, broadband transmission capability. Meanwhile, cardioid directivity is obtained at 1.4 kHz and low-frequency directivity is realized.

“…Among the various FTs, Class IV FT is a particular type which shows superior performance in terms of low-frequency and high-power property [ 21 , 22 , 23 , 24 ]. A Class IV FT currently consists of a shell in the form of elliptical cylinder and active diver stacks inside.…”

Section: Introductionmentioning

confidence: 99%

A Conformal Driving Class IV Flextensional Transducer

Zhou

Lan

Zhang

et al. 2018

Class IV Flextensional Transducers (FTs) are the most popular among various FTs used as low-frequency and high power underwater acoustic sources. However, an undeniable fact exists in Class IV FTs is that the resonance frequency of breathing mode regulator used is fairly raised by its longitudinal driver stacks. In this research, a conformal driving Class IV FT in which the driver stacks are kept conformal with its oval shell was proposed aiming at the limitations of conventional driving Class IV FTs described above. The device exhibits competitive Transmitting Voltage Responses (TVRs) but much lower operation frequencies with respect to conventional driving Class IV FTs, through the designs of conformal and segmentally controlled driver stacks. Geometric parameters analysis was carried out extensively by Finite Element (FE) simulations for the design optimizations and then a conformal driving Class IV FT resonating at 510 Hz (45% approximately lower than that of conventional driving Class IV FT with the same shell geometry) was finalized. Subsequently the conformal driving Class IV was fabricated and tested in the anechoic tank experimentally. Good agreements of both FE predictions and experimental results demonstrate its low-frequency and small-size acoustic performance.