Dynamics of high-speed slender body penetration through ice sheets into water

To investigate the complex unsteady and multiphase dynamics of slender bodies penetrating ice sheets into water at high speeds, a coupled Arbitrary Lagrangian-Eulerian (ALE) and Finite Element Method (FEM) numerical framework was established and validated against experimental data. Both numerical and experimental approaches were employed to elucidate the ice failure mechanisms, energy absorption characteristics, and the evolution of the water-entry flow field. The results indicate that impact velocity governs the ice failure mode.Specifically, as the velocity increases, the failure mechanism transitions from global structural bending to localized crushing (occurring at approximately 150 m/s under the studied conditions), resulting in a non-monotonic relationship between crater size and impact velocity. The angle of attack (AoA) is identified as a critical factor for trajectory stability; results reveal a critical threshold (observed at 4°), beyond which significant asymmetric loading induces trajectory deviation and cavity distortion. Conversely, at small AoAs (defined as α ≤ 4° in this study), the ice hole walls exert a constraining effect that assists in attitude rectification. Furthermore, variations in ice thickness shift the penetration mechanism from thin-plate shearing to semi-infinite localized compaction, fundamentally altering the energy dissipation efficiency. These findings provide a theoretical basis for the design of cross-media vehicles operating in polar environments.