Parametric study on the underwater formation characteristics of a radial composite shaped charge

This paper innovatively proposes a novel radial composite shaped charge structure, which integrates an inner shaped charge and an outer detonation charge into a single unit, forming a combined shaped-charge and detonation damage mode. The Arbitrary Lagrangian-Eulerian (ALE) algorithm is employed, together with theoretical analysis and experimental validation, to investigate the formation process, motion characteristics, and cavitation evolution of the underwater jet produced by this charge. The results indicate that the liner geometry, material properties, explosive type, and initiation method collectively determine the kinetic energy level and morphological characteristics of the jet, thereby regulating the cavitation evolution process and the final cavity dimensions. Moreover, the cavitation process induced by the underwater jet motion exhibits distinct stage characteristics: initially dominated by axial stretching, which controls the axial extension of the cavity, followed by a regime dominated by radial expansion, which governs the growth of the maximum cavity diameter. Within the parameter range examined in this study, the combination of a conical copper liner and an ROB (DNAN/HMX(20/80))inner charge demonstrates favorable overall performance. Under this configuration, the jet length reaches 36 cm, and the jet tip velocity remains approximately 2000 m/s after penetrating 42 cm of water.