Stability analysis of high-speed spin-stabilized supercavitating projectiles during water entry

This study explores the fluid-structure interaction (FSI) phenomena associated with spin-stabilized supercavitating projectiles and the influence on the structural stability of the projectiles. Fluid-structure interaction simulations are performed on projectiles during high-speed water entry, and the results are contrasted with those derived from rigid body models. The results highlight that rigid body simulations are unreliable at high spin rates, showing considerable inaccuracies. Both FSI and theoretical analyses identify a critical spin angular velocity above which significant structural deformation occurs, compromising stability. Theoretical analysis has identified an optimal spin angular velocity, calculated as the critical velocity multiplied by 1/√2, which minimizes bending deformation. The findings from this study are critically important for the design of spin-stabilized supercavitating projectiles, suggesting the use of the natural frequency of the projectile to estimate critical spin angular velocity and thereby guide design strategies to enhance structural stability. This approach offers a practical strategy to avoid excessive deformation and optimize the projectile's trajectory stability during high-speed water entry.