Studies on an Electric Discharge Underwater Sound Source

摘要

Operation of the inverse pinch geometry in underwater electrical discharges, viewed as acoustic sources, has been evaluated. The basic characteristics of the signal radiated (e.g., distance dependence, waveform, etc.) are similar to general underwater discharges and explosive sources. Critical dependence of the energy efficiency on the electrical damping characteristics of the discharge circuit (including the discharge itself) was found. However, high speed optical investigations disclosed that, under the achievable energy and configuration limitations, it was not possible to produce a discharge of the desired cylindrical symmetry. Auxiliary investigations demonstrated that the configuration produced satisfactory strong (arc-like) discharges in water equivalent in salinity to sea water; however, the increased energy loss during initiation of the arc, due to the higher conductivity of the water, tended to decrease overall efficiency in saline solutions. It was also demonstrated that near field acoustic signals may be shaped to a considerable extent by tailoring the waveform of the electrical discharge (with significantly decreased energy efficiency, however). (Author)