Modelling of acoustic antennas with a combined finite-element-boundary-element-method

A technique for the computer modeling of fluid loaded electromechanical transducers is introduced. This method is based on the coupling of piezoelectric and acoustic finite elements with acoustic boundary elements. The new technique is superior to the pure finite element method, particularly with respect to the necessary computer resources, whenever the fluid region to be modeled is large. The restriction of the boundary element method to continuous wave applications is overcome by Fourier analysis of the exciting pulses and by performing a computer run for each spectral line. An annular array antenna as used in acoustical imaging is analyzed. With the new method, precise computer simulation of the acoustic field of that antenna could be performed on a general-purpose workstation