| 摘要 |
The novel method substantially reduces the pressure pulse generated by an implosion of a cavity within a body of water by aborting the implosion. The abortion of the implosion is produced by generating within the cavity an explosion at the instant that this cavity attains its maximum volume. The method can also be used to generate within a body of water an impulsive acoustic signal by generating a first explosion within the body of water to produce therein a powerful pressure pulse and a cavity of very low pressure, and then generating a second explosion within the cavity so as to establish hydrostatic pressure inside the cavity while the volume of the cavity remains within a few percent of its maximum volume. The apparatus comprises first and second explosive generators which consecutively create two explosions within the body of water: a first explosion which produces within the body of water a powerful acoustic pulse and an expanding cavity of very low pressure, and a second explosion which establishes hydrostatic pressure within the cavity while the volume of the cavity remains within a few percent of its maximum volume, thereby substantially reducing the ensuing secondary pressure pulses.
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