| 摘要 |
<p>Prodn. of the pressure waves from an explosive body comprises forming a detonator cord extending in a helix of length proportional to the dia. of the windings. The pitch dimension is such that the detonation velocity in the direction of the axis of the helix is equal to the velocity of the sound pressure wave in the transfer medium. Pref. the support tube has a spiral groove for positively locating the detonator cord. Enables the explosive body, partic. under water, to be located in a position remote from the target. It is highly directional e.g. with an explosive helix of length 50 cm and dia. 2,5 cm. animal life was killed and glass sphere exploded in the direction of propagation at 10m, while in the opposite direction there was no action on either the animals or the glass spheres at a distance of 1m. Seismic measurements can be made without perturbing echoes. The process can be used for sheet metal forming under water, and underwater signalling over long distances.</p> |
