Velocity tracking of shaped charge wire formation and propagation toward the target

The formation of shaped charge jets is traditionally studied experimentally using flash X-ray and high-speed camera images. Sequential images obtained through these methods provide insight into the overall properties of the jet, such as jet tip velocity and outline shape. Numerical methods are validated using experimental results of the macroscopic properties by taking absolute velocity contours through the jet and comparing the outline shape. These methods do not describe where, and in which order, discrete parts of the shaped charge liner are located in the jet after formation. Shaped charge jet formation is studied here numerically by tracking the velocity in the flow field using stationary gauges and by placing dynamic gauges on the shaped charge liner. This method provides insight into the physical mechanism of jet formation. It is generally assumed that the shaped charge jet forms from liner inversion, where the liner tip becomes the jet tip that first penetrates the target. This work shows that the liner tip does not form part of the jet but is rather absorbed into the slug. Similarly, PER theory assumes that the outer part of the liner (next to the explosive) flows into the slug and the inner part flows into the jet. It is shown here that this assumption is not valid in all cases. This study is a proof of concept to highlight the advantages of using the method of simultaneous liner and flow field velocity tracking to aid shaped charge optimization activities.