Composite Fueling System for Miniature Combustion Power Sources

Not Available A directional underwater acoustic transducer for modem use will be developed. The transducer will provide both vertical and horizontal directionality and operate in the 8 kHz to 20 kHz spectrum with a bandwidth of 5 kHz. The proposed transducer would provide vertical directionality through its length and horizontal directionality through multi-modal excitation of the cylinders. We plan to use a combination of omni-directional, dipole and possibly quadrupole modes of vibration to attain a directional and steerable beam. The modes will be excited and steered through selective electrical summing of the signals on the silver striping on the cylinder. It has been shown that highly directive beams may be obtained from spherical transducers [J. L. Butler and S. L. Ehrlich, Superdirective spherical radiator, J. Acoust. Soc. Am., 61, 1427-1431 (1977)]. We plan to extend this to the case of a cylindrical radiator. Analytical and finite element modeling will be performed to verify expectations before the design is implemented. We believe this approach will yield a design compatible with current acoustic modems and provide an approach that would yield production cost below $1,000.