Underwater Spiral Wave Sound Source Based on Phased Array with Three Transducers

Abstract

This paper realizes an underwater spiral wave sound source by using three omni-directional spherical transducers with three different phases. The pressure distribution of the sound field for a phased array is derived using the superposition theory of sound field. The generation of spiral wave field is presented, the relationship between the performance of phased array sound field and the array parameters is analyzed, and also verified by the finite element method (FEM). A spiral wave sound source with three spherical piezoelectric ceramic transducers is then designed and fabricated based on FEM simulation, and the performance of the sound source is analyzed. Measurements are made in a reverberation pool, and the result shows that the fabricated spiral wave sound source is capable of producing a spiral sound wave. Under a frequency of 3.5 kHz, the phase directivity has a fluctuation of ±21°, and the amplitude directivity range is 4.3 dB, which verifies the realization of the spiral wave sound source.

In Lab Demonstration of an Underwater Acoustic Spiral Source

“…In 2018, Lu et al developed a Phased-Spiral source using 8 longitudinal vibrating elements that vibrate due to multiple piezoelectric ceramic hollow cylinders [14]. One year later, the same authors developed a more simple Phased-Spiral source using a group of 3 omnidirectional spherical transducers [15].…”

“…2) as the one developed in [11]. However, the four quadrants are not acoustically isolated, thus resulting in a transducer with four omnidirectional monopoles that can be driven by four independent signal generators simultaneously as is the case of the spiral source developed in [15] which uses 3 independent omnidirectional acoustic sources. The spiral source's prototype was made using a standard PZT-4 piezoelectric ceramic cylinder (Fig.…”

In-Lab Demonstration of an Underwater Acoustic Spiral Source

“…The developed spiral source prototype has a cylindrical shape with four quadrants, A, B, C, and D (see Figure 2 ) as the one developed in [ 23 ]. However, the four quadrants are not acoustically isolated, thus resulting in a transducer with four omnidirectional monopoles that can be driven by four independent signal generators simultaneously as is the case of the spiral source developed in [ 27 ], which used three independent omnidirectional acoustic sources.…”

“…The absolute angle error was less than 23° and 3° before and after the calibration, respectively. Thus, the prototype in question, at 30 kHz, had the worst performance before the calibration compared to the maximum absolute angle errors of 4°, 20°, 10°, and 21° in [ 18 , 25 , 26 , 27 ], respectively. On the other hand, it performed better after the calibration, at all tested frequencies, compared to the state-of-the-art work [ 25 ] with the maximum absolute angle error of 10°.…”

“…In 2018, Lu et al developed a Phased-Spiral source using eight longitudinal vibrating elements, which vibrated due to multiple piezoelectric ceramic hollow cylinders [ 26 ]. One year later, the same authors developed a simpler Phased-Spiral source using a group of three omnidirectional spherical transducers [ 27 ].…”