Simulating Lateral Drift of a Shaped Charge Jet in ALEGRA

Abstract Shaped charge jet (SCJ) research has long been an active area for industrial, academic, and defense organizations. Traditionally, the depth of penetration (DOP) has been one of the most important metrics for the evaluation of shaped charge jet performance, and early 1D analytical penetration models based on hydrodynamic penetration were created with this metric in mind [1]. As the standoff of a shaped charge jet increases, the DOP reaches a maximum and then begins to decrease. A simple 1D hydrodynamic penetration model must account for the totality of the jet material on axis penetrating, and as a result experimental DOP at longer standoffs is lower than the analytical models predicted. Some analytical models reasoned that since a velocity gradient evolves as a SCJ forms, contributions to penetration from jet material below a minimum jet or penetration velocity should be eliminated. These were better able to account for the difference between analytical hydrodynamic and experimental DOPs [2]. The actual difference between analytical hydrodynamic penetration theory and experimentally recorded values is now regarded to be a result of 3D phenomena including particle tumbling and motion transverse to the jet axis known as lateral drift [2]. The origins of these 3D phenomena have been attributed to sources including variability in the uniformity of the explosive charge or the microstructure of the liner [2,3].