Underwater Shock Wave Generated by Exploding Wire Ignited Energetic Materials: Wave Reconstruction and Physical Model Test

Underwater shock wave (SW) generated by the combination of energetic material (EM) and electrical wire explosion (EWE) are attracting more and more attention in the field of reservoir stimulation. However, it is difficult to study the characteristics of hybrid SW that contains multiple SW components with different intensities and time delays. In order to optimize the formula of EM and the parameters of pulsed power supply, it is necessary to establish the relationship between exploding wire, formulation of EM and SW. In this work, we described hybrid SW waveforms with four simple functions based on the mechanism of ignition, which not only reflects the waveform characteristics, but also ensures the accuracy of the impulse and energy density of the reconstructed SW. The characteristic parameters were then extracted so as to adjust the ratio of oxidant and reducing agent to achieve the purpose of controlling the release rate of chemical energy. In addition, hybrid SWs were used in the physical model test of cracking concrete to study the fracturing effect, and complex fracture networks were created after operation. Combined with high-speed photography and the numerical results of Autodyn simulations, fracturing mechanism of the hybrid SW was analyzed to give suggestions for further formulation optimization.