Powerful water-plasma explosions

Arc-liberated chemical energy exceeds electrical input energy

“…Soon after Frungel's publications, water arc explosions found applications in electrohydraulic metal forming (Gilchrist & Crossland 1967) and underwater pulse echo sounding (Frungel 1965). Not until the mid-1980s was the scientific basis of the puzzling explosions more extensively researched at MIT (Azevedo et al 1986). It was then shown that the discharge of 3.6 kJ of stored capacitor energy would create pressures in excess of 20 000 atm, in 7 ml of saltwater : 3.6 gm of water was ejected from the accelerator barrel with a velocity of the order of 1000 m s −" , and then punched a " # -inch-diameter hole through a " % -inchthick aluminium plate (Graneau and Graneau 1996).…”

“…This is just over 5 % of the latent heat. Furthermore, extensive analysis presented in Graneau and Graneau (1996) and Azevedo et al (1986) has demonstrated that electrodynamic forces could only amount for a negligible portion of the kinetic energy developed in arcs. Therefore almost all of the input energy E # (E C in Fig.…”

Solar-energy liberation from water by electric arcs

“…Pure water is a good dielectric, and breakdown is difficult to achieve. Saltwater and tapwater are more easily ionized (Azavedo et al 1986) because of an electrolytic conduction phase that wastes much of the energy supplied to the water without producing any ions. The experiments described in this paper were therefore performed with distilled water.…”

“…It was clearly recognized from the start that water arcs were relatively cold and no steam was created. Measurements of arc explosion forces were started at MIT (Graneau and Graneau 1985), in 1985 and continued at Northeastern University (Azavedo et al 1986). On one occasion (Graneau and Graneau 1996), a 3.6 g water mass, travelling at approximately 1000 m s −" punched a half-inch diameter hole through a quarterinch thick aluminium plate.…”

“…The dimensionless factor kh is now an experimentally determined quantity. When water arc explosion forces were measured over ten years ago (Azavedo et al 1986), it was found that 1000 kh 7000. This fact has been confirmed in all subsequent experiments.…”