Dynamic stability of liquid-filled projectiles under a thrust

Fluid–structure interaction (FSI) problem is investigated to study the dynamic stability of liquid-filled projectiles under a thrust. The projectile is modelled as a flexible cylindrical shell, and the thrust is modelled by the constant and pulsating follower force. To analyze the fluid and structure simultaneously, hydrodynamic pressure of the liquid and elastic deformation of the structure are taken into consideration. We assume that the fluid is incompressible and having free-surface effect. In the numerical study, natural frequencies for various filling ratios of liquid of the cylindrical shells are analyzed and compared with the previous experimental and theoretical works for with and without the free-surface effect. Further, the results on dynamic stability of partially liquid-filled slender cylindrical shells under constant and pulsating follower force for various filling ratios of the fluid are summarized. Lastly, the effects of length and thickness of the shell are studied in detail.