TABLE OF CONTENTS The previous six chapters presented the status of underwater sound transducers and arrays at the beginning of the twenty first century in considerable detail, but with a minimum of analytical background. The present chapter begins to fill in the background with detailed discussions of the models and methods used in transducer analysis and design [1, 2, 3, 4, 5a]. The following chapters will continue with further discussion of important transducer concepts such as the electromechanical coupling coefficient, analysis of nonlinear effects in transducers, calculation of acoustic radiation from transducers and measurement methods for the evaluation of transducers.
The underwater sound electroacoustic transducer is a vibrating device which, as a projector, is set into motion by electrical means causing it to alternately push and pull on the water and radiate sound. As a hydrophone, sound waves in the water set the transducer into motion thus generating an electrical signal. The electroacoustic transducer is part acoustical at its moving surface in contact with the acoustic medium, part mechanical as a moving body controlled by forces, and part electrical as a current controlled by voltage. Thus electrical equivalent circuits representing the acoustical and mechanical parts make possible an electrical simulation of the whole transducer. This facilitates analysis and design, and is especially useful since transducers are always connected to electrical components such as a preamplifier for a hydrophone or a power amplifier with tuning and transformer circuits for a projector.
In Section 2.8 we indicated how an electroacoustic transducer may be represented...
