Transducers utilizing single crystal piezoelectrics as the active elements have been shown to exhibit broader operating bands, higher response levels, and higher power efficiency than transducers using piezoceramics while also reducing the size and mass of the transducer (Moffett et al., J. Acoust. Soc. Am., 2007). The key to these high performance characteristics is the piezocrystal's inherent high electromechanical coupling coefficient. One potential application is to replace multiple narrowband piezoceramic transducers with a single broadband piezocrystal transducer which reduces the system's weight and size. This is very important for the new generation of smaller and power efficient unmanned underwater vehicles (UUVs). A third application is for use in very broadband communication networks. The work presented here focuses specifically on the design, modeling, and construction of Tonpilz transducers using piezoelectrics as the active material. The modeling includes lumped element and finite element analysis to approximate the performance of these transducers. These models serve as the main structure of an overall iterative design process. The objective of this research is to compare the performance characteristics of a piezocrystal and a piezoceramic Tonpilz transducer and to validate the models by comparing the model predictions with experimental results. / text

Tonpilz-type transducers are the most commonly used projectors in underwater acoustic applications. However, no complete design approach is available in the literature for such transducers. The present study aims to fill this gap in the literature by providing a systematic design approach for the Tonpilz-type transducers. The proposed methodology involves the use of different analytical models and a finite element model of such transducers. Each model provides a different level of accuracy that is tightly correlated with the models complexity and computational cost. By using these models sequentially starting with the simplest and fastest model to yield an initial design and concluding with the most detailed and accurate model to yield an optimized final design the overall design time is reduced and greater flexibility is given to the designer. An overview of each of these four models is given. The constructed models are benchmarked against published experimental data. The overall design methodology is demonstrated by systematically applying the four models to design a Tonpilz-type transducer. Possible improvements to the proposed methodology are discussed.