Fundamental Characteristics of Underwater Shock Wave due to Underwater Explosion of High Explosives

Fundamental characteristics of underwater shock waves generated by underwater explosion of high explosives are investigated by both experimentally and by numerical simulation. The attenuation process of the underwater shock wave is also investigated theoretically using a method of characteristics. Slab explosives are used in the experiments. Streak photographs are taken by a high speed camera using a conventional shadowgraph system. When the detonation wave propagates into the explosive, the underwater shock wave is generated at the boundary between the slab explosives and the water. The incident angle of the underwater shock wave is the same as that obtained by the impedance matching method between the explosives and water. The angle then changes due to the effects of interaction with the expansion wave occurring due to the expanded product gas. The attenuation process of the underwater shock wave is well explained by the method of characteristics.