A lumped-circuit model for the radiation impedance of a circular piston in a rigid baffle

The radiation impedance of a piston transducer mounted in a rigid baffle has been widely addressed ill the literature. The real and imaginary parts of the impedance are described by the first order Bessel and Struve functions, respectively. Although there are power series expansions for both functions, the analytic formulation of a lumped circuit is not trivial. In this paper, we present all empirical approach to the derivation of a lumped-circuit model for the radiation impedance expression, based oil observations on the near-field behavior of stored kinetic and elastic energy. The field analysis is carried out using a finite element method model of the piston and surrounding fluid medium. We show that fluctuations in the real and imaginary components of the impedance call be modeled by series and shunt tank circuits, each of which shape a certain section of the impedance curve. Because the model is composed of lumped-circuit elements, it call be used in circuit; simulators. Consequently, the proposed model is Useful for the analysis of transducer front-end circuits.