EXPLOSION PRODUCT REDISTRIBUTION MECHANISMS FOR SCALED MIGRATING UNDERWATER EXPLOSION BUBBLES
NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CA
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A submerged gold wire was electrically exploded to simulate a very deep underwater nuclear detonation. These small-scale tests were conducted in a test tank in which the air pressure may be varied to obtain various strengths of buoyant bubble migration. The mechanics of explosion bubble formation, pulsation, and migration are discussed, and relevant relationships are derived for scaling large-yield bubble behavior in the laboratory by variation of environmental parameters. The mechanisms by which the explosion products, initially at the bubble center during the first cycle, are redistributed by bubble bottom collapse, compression, reexpansion, and migration, are investigated. The experimental technique involved physically sampling the bubble and its environment at the second bubble maximum to define the extent and nature of explosion product re-distribution. Three different shot conditions were investigated, corresponding to a rest-point condition, a condition characterized by slight upward migration, and one characterized by strong upward migration. In all cases, it was found that most 77 to 94 of the explosion products are lost to the environment by the time of the second bubble maximum. The probable mechanisms for this loss are discussed, and rules are derived for application of these results to full-scale underwater bursts.
- Fluid Mechanics