Control of Shaped Charge Jets Through Non-uniform Confinement

The shaped charge jet device has provided an efficient means of accelerating mass in hypervelocity studies for a broad variety of research and applications. This effort extends traditional 1-dimensional liner collapse to 2-dimentional manipulation and energy control of the jetting mechanism. Various confinement conditions were explored to induce non-concentric liner collapse conditions and produce planar jet structures. Symmetric, but non-uniform confinement produced 2-dimensional ‘spreading jets’ that have utility in cutting metal plates, pipe cutting, demolition and/or demilitarization of outdated or hazardous ordnance scenarios. First, parametric studies were numerically conducted to scope confinement thickness, confinement material, and the uniformity in circumferential coverage. Then, configurations were selected to best cover the design space and physical experiments were carried out with dual- orthogonal flash radiography. Lastly, the results were compared to the numerical simulations and analysis was conducted to examine the mechanism for mass re-distribution and extraction of the physics from explosive loading, its reflections off the non-uniform case, and liner collapse and jetting process. Three shots were conducted using the Viper liner and the steel thickness of 5.5 mm since it provided the maximum confinement effect. The three shots examined the following gap sizes of 30°, 60°, and 90°, and confirmed the numerical predictions of increasing radial expansion with gap size. The integrated approach of numerical modeling and experimental validation resulted in a higher fidelity insight into the complex jetting mechanism for improved future designs.