Scaling Underwater Exploding Wires

The parameters of peak pressure and decay time constant of the shock wave caused by electrically exploding wires underwater have been compared to TNT data and theory. The wire used was 5-mil, ½-in. Nichrome. Electrical energy up to 100 J was stored in the capacitor. The results indicate that peak pressure reduces to the same kind of similitude functions as those used for TNT data if losses owing to the circuit and heating of the wire are accounted for. On this basis, an expression for the equivalent weight of TNT (on the order of micropounds) is presented in terms of the electrical parameters and heat of detonation. The reduced time constant for exploding wires also reduces to the same kind of similitude function as those used for TNT data. The magnitude and behavior of the reduced time constant are comparable to TNT data.