Effects of Circuit Inductance on Electrical and Shock Wave Characteristics During Underwater Copper wire Explosion

Abstract

Circuit inductance is an important parameter at underwater electrical wire explosion (UEWE) which is closely related to the energy deposition rate to the load wire. In this work, the circuit inductance was varied within a wide range from 1.55 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\Box\mathrm{H}$</tex> to 93.2 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\Box\mathrm{H}$</tex> by inserting inductive coils to study its effects on electrical and shock wave (SW) characteristics. Experimental results showed that SW peak pressure several-emaway from the wire is not sensitive to the increase of circuit inductance when properly choosing the diameter of load wire: the SW peak pressure obtained with varied diameter (with constant energy storage and wire length) only showed a decrease of 30% as the circuit inductance increased by 60 times from 1.55 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\Box\mathrm{H}$</tex> (0.3 mm diameter, 19 MPa) to 93.2 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\Box\mathrm{H}$</tex> (0.2 mm diameter, 13 MPa). Hydrodynamic calculations based on a coupled model were used to explain the experimental results. These results indicated that for a practical UEWE system, long cable can be used to transfer the pulse current so that the energy storage can be far away from the load while keeping an acceptable loss of the capability of generating strong SWs, which greatly improves the flexibility of system designing for example by enabling much larger energy storage for certain harsh working environments.