An ideal jet that does not deviate from the charge axis is unrealistic due to manufacturing imperfections and jet fracture. At a large stand-off, the penetration depth of the jet particles that deviate from the charge axis is significantly reduced. The penetration process of a shaped charge jet into spaced plates with large spacings can be thought of as the residual jet passing through the front plate into the subsequent plate at various stand-off distances. Ideal jet theory significantly overestimates the penetration performance of shaped charge jets into spaced plates. This study systematically investigated the drift velocity and gap effects that govern shaped charge jet penetration through spaced plate configurations. A novel theoretical penetration model that incorporates non-ideal flow characteristics has been developed to quantitatively describe the interactions of a shaped charge jet with multiple spaced plates. Due to the combined effects of a high drift velocity and a large stand-off distance, it is impossible for low-velocity jet particles to traverse through spaced plates and reach the witness plate. Experimental results indicated that the tail of a shaped charge jet with a low velocity does not contribute to the penetration process and has no impact on the penetration depth of the witness plate. The non-ideal jet penetration model can accurately predict the velocity range of the shaped charge jet as it passes through spaced plates as well as the penetration depth of the residual jet on the witness plate.
Xiao et al. (Fri,) studied this question.