Underwater explosion

When an explosive is detonated in water, a shock wave propagates through the water accompanied by a bubble. The chemical energy of the explosive is converted into shock wave energy and bubble energy. The volume of the bubble is increased by the expansion wave and decreased by the compression wave in an oscillatory fashion. The maximum size of the bubble is determined according toili i i 

Experimental results of underwater explosion tests using an emulsion explo-sivecomposed of ammonium nitrate and hydrazine nitrate showed 0.85 MJ kg for the shock wave energy and 2.0 MJ kg for the bubble energy. The shock wave energy of underwater explosions is increased by the addition of aluminum powder to the explosives. The aluminum powder reacts with H2O molecules in the bubble. Large amounts of Hj molecules and heat are produced by the oxidahon of the A1 with H2O according to  

The AI-H2O reaction increases the temperature and the number of moles of gas in the bubble by the production of H2 molecules. The pressure in the bubble is thereby increased. As a result, the bubble energy and shock wave energy are increased. It must be understood that the oxidation of aluminum powder is not like that of gaseous reactants. Reaction occurs at the surface of each aluminum particle and leads to the formahon of an aluminum oxide layer that coats the particle. The oxidized layer prevents the oxidation of the interior particle. The combustion efficiency of aluminum parhcles increases with decreasing particle size.l =l The shock wave energy and bubble energy are increased by the use of nano-sized aluminum powders. 

1 Zeldovich, la. B., and Kompaneets, A. S., Theory of Detonation, Academic Press, New York, 1960. 

2 Strehlow, R. A., Fundamentals of Combustion, International Textbook, New York, 1968. 

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R. H. Cole, Underwater Explosives, Princeton University Press, Princeton, N.J., 1948. 

Refs 1) R.M. Cole, Underwater Explosives , Princeton Univ Press (1948) 2) Cook (195 8),... 

Cole, R. H., Underwater Explosion. Princeton University Press, New Jersey, 1948. Cook.M. A., The Science of High Explosives. Reinhold, New York, 1958. 

Although it is possible to define the potential or kinetic energy in blast waves, it is not customary in air blast technology to report or compute these properties. For underwater explosions, the use of "energy flux density" is more common. This quantity is given approximately by... 

Cole, R.H. Underwater Explosions, Dover Publ., New York 1965 Wahle M. und Begrich, K. Der Sprengmeister, Heymanns, Koln 1969 Holluba, H. Sprengtechnik, 3. AufI., Osterreichischer Gewerbeverlag, Wien 1985... 

Figure ll ICx Technologies SeaDog underwater explosives detection sensor mounted on an autonomous underwater vehicle. Figure courtesy of ICxTechnologies. 

M. Dock, J.E. Sikes, M.E. Fisher, Underwater Explosives Detection Using a Chemical Sensing Method, Sixth International Symposium on Technology and the Mine Problem (MINWAILA),... 

Silver nitride (Ag N) Sensitive to shock, underwater explosive upon contact with water. 

Mouritz, A.P. (1995). The damage to underwater GRP laminates by underwater explosion shock loading. Composites Sci. Technoi. 55, 365 374. 

Roth, J., Underwater Explosives, Encyclopedia of Explosives and Related Items, Vol. 10, US Army Research and Development Command, Dover, NJ, pp. U38-U81, 1983. 

Kato, Y, Takahashi, K., Torii, A., Kurokawa, K., and Hattori, K., Underwater Explosion of Aluminized Emulsion Explosives, Energetic Materials, 30th International Annual Conference of ICT, 1999. 

Aluminum (Al) is a silver-colored light and soft metal used as a major component of aluminum alloys, which are used to construct aircraft and vehicles, similar to Mg alloys. However, Al is known as a readily combustible metal. Thus, Al particles are used as major fuel components of pyrolants. Al particles are mixed with ammonium perchlorate particles and polymeric materials to form solid propellants and underwater explosives. The reaction between aluminum powder and iron oxide is known as a high-temperature gasless reaction and is represented by ... 

Dock, M., J. Sikes, M. Fisher, and M. Prather. Chemical detection of underwater explosives. 2004 Mine Countermeasures Demining Conference/MINWARA, Canberra, Australia, February 2004. 

The growth and collapse of cavitation bubbles is commonly described by considering irrotational expansion of a spherical cavity in an incompressible liquid of infinite extent, subject to the unsteady form of Bernoulli s equation (B3, P5). Effects of compressibility and bubble migration must also be considered for oscillating bubbles produced by underwater explosions (B3, C5). 

F.W, Brown, "Theoretical Calculations of ExplosivesII. Explosion Pressures , USBurMinesTechPaper 643, 1942 lla)Ya.B. Zel dovich ZhEksper i TeoretFiz 12, 389(1942) (Pressure and velocity distribution in the detonation products of an explosion, specifically for spherical propagation of the detonation wave) 12) J.G. Kirkwood et al, "The Pressure Wave Produced by an Underwater Explosion , OSRD Repts 588, 670 813(1942) 12a) V. A. 

Refs 1) J.S. Coles, "Summary of Underwater Explosive Comparisons , OSRD 6241(1946) 2) Anon, "Explosives and... 

Cole, "Underwater Explosions , Princeton UnivPress, Princeton, NJ (1948), Chapter 3 50) R. Courant K.O. Friedrichs, "Supersonic Flow and Shock Waves , Interscience, NY (1948) (Reprinted in 1961) 51) A. Eyring... 

Refs 1) J.G. Kirkwood E.W. Montroll, "The Pressure Wave Produced by an Underwater Explosion , OSRD Rept 676(1942) PB32183 2) Division 2 NDRC, Interim Report on Underwater Explosives and Explosions , UE-32 OSRD 4874, March-April. (1945) 3) R.H. 

Cole, "Underwater Explosions , Princeton-UnivPress, Princeton, NJ (1948) 4) H.G. 

Underwater explosions and shock waves) 328 (Underwater strength.methods) 331-35 (Underwater sensitivity) 8) L.V. Al tshuler et al, "Phase Transformations of Water Compressed by Strong Shock Waves , Soviet Physics-Doklady 3, 761 (1958) 9) C.H. Winning, "The Under-... 

Another important characteristic of an explosive, which might influence the force is the density abbrd as d. This is especially important in underwater explosions, such as of sea mines, torpedoes, depth bombs and bombs dropped alongside a ship. If the volume in which the expln occurs is large, compared... 

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