Time-domain modeling of composite arrays for underwater imaging

Time-domain, finite element simulations are used to explore some design issues and the practical modeling envelope for 1-3 composite arrays in underwater pulse-echo imaging transducers. This provides a relatively new perspective on the design problem via large-scale 2D and 3D transient simulations that include many piezoelectric pillars within the composite. Cross-talk from a prototype 150 kHz array is modeled and compared to data Some of the composite slab's dispersion behavior is derived from its impulse response and used to interpret cross-talk. Numerical experiments on a 500 kHz design demonstrate effect of pillar taper and distribution-freedoms offered by injection molding. Fourier optics manipulation of the projected acoustic field is illustrated. These studies support an ongoing design and fabrication collaboration under the aegis of United States and Commonwealth naval agencies