Wide-Band Array Operations of Flextensional Sound Sources

摘要

The use of low frequency sonar in shallow water, or in any environment whereboundary interactions occur, is fraught with difficulties. While the boundary interactions are desirable from the standpoint of navigation, these same interactions pose severe problems in search sonars. Developed primarily for use in deep water, low frequency sonars are typically designed to operate near resonance. As such, full power operation of such devices can be self defeating due to the reverberation caused by boundary interactions. An alternative is to examine off-resonance broad band operation of such systems. Near resonance, the directivity of an array of low frequency sources, is dominated by the array aperture. However, as the frequency is increased, the directivity of the elements as well as the changing nature of the array interactions and diffraction also require consideration. In addition to affecting directivity, hot spots may arise causing local cavitation. This paper will discuss the results of broadband performance modeling of a two-dimensional array of flextensional projectors including the effects of interactions and beamsteering on tuning and power requirements.