Dept. of Telematics Eng. and Dept. of Elec. Eng., Natl. Fisheries Univ. of Pusan, Pusan, Korea 608-737
A numerical method for evaluating the electroacoustical characteristics of a complex structure of transducer immersed in an infinite acoustic medium is adopted. The mechanical, electrical, and acoustical response of the transducer in the finite region is modeled by the finite element method; the Sommerfeld radiation condition to the infinite region is modeled by the hybrid-type infinite element method, and the boundary between both regions is formulated with compatibility of the acoustical admittance in both regions. The numerical results, which include the elastic response, the radiation impedance, and the input electrical admittance, are given for a single piezoelectric cylinder and a coaxial two piezoelectric cylinder array with various polyurethane windows. The technique allows one to interpret and to optimize design parameters such as geometrical shape and mechanical properties of structure components, electrical characteristics of piezoelectric elements, etc.