Modeling of shock-wave generation in water by electrical discharges

We have performed one- (1-D) and two-dimensional (2-D) hydrodynamic simulat ions for studying shock production in water for two geometries of interest ill rock-fragmentation. Two-dimensional simulations have been performed for parameters similar to those in [1], [2], These simulations, using realisti c equations of state for water and the electrode material, yield pressures in the same range as experimentally reported values. With some improvements , the code could be used for optimization of such experiments. One-dimensional simulations have been performed for an axisymmetric cylinde r configuration similar to that in [3], Two different power levels have bee n examined, The spatial profile of power deposition in water Q(r) is repres ented by a functional form relevant to the problem of interest. With a long -duration electrical pulse, the pressure profile inside the cavity is nearl y uniform at the end-of-pulse, regardless of the deposition profile, The ge neral pressure level rises with the "peakedness" of Q(r), This means that f or the same water mass and for the same energy input, we could generate hig her pressures with more peaked profiles. Conversely, a required pressure le vel could be achieved with lesser electrical energy by depositing energy cl oser to the cylinder asis, This should help in minimizing the electrical en ergy requirement for a given application.