Enhancement of Shock Wave Generated by Underwater Electrical Wire-Array Explosion at a Fixed Energy and Mass of Wire-Array

摘要

An energy-efficient method for further enhancing the shock wave generated by underwater electrical wire-array explosion at a fixed energy was developed. Based on the configuration of a cylindrical wire-array, the method was to replace one wire of 0.2-mm diameter with N thinner wires, while the total mass of these N wires was kept equal to the mass of that 0.2-mm wire. As the number of wires increased, the maximum wave pressure at the axis of the wire-array increased from 28 MPa for 1 wire of 0.2-mm diameter to about 90 MPa for 16 wires of 0.05-mm diameter. The shock wave generated by one single wire was proportional to 1/(N)(1/2) rather than 1/N, which should be the reason for the enhancement. The interaction of shock waves from each single wire was discussed. It might be roughly divided into two kinds, "non-overlapping" and "overlapping." The "non-overlapping" occurred only in the wire-array with not more than four wires. While propagating toward the axis of the wirearray, the shock waves from the wires did not overlap even when they were close to the axis. The shock wave at the axis is simply the summation of the shock waves from all wires. In contrast, the "overlapping" occurred in the wire-array with not less than seven wires. The shock waves from the wires overlapped even when they were far from the axis. Due to the converging effect of shock waves, the shock wave at the axis is considerably lower than the summation of shock waves from all wires, especially when the number of wires is larger.