On the penetration of rigid projectiles in water

We performed an extensive numerical study on the penetration of rigid projectiles into water. The 2D simulations were focused on evaluating the drag coefficients of projectiles with various nose shapes and on their dependence on the projectile's impact velocity. To achieve simulation convergence the mesh size was found to have at least 11 cells on a target segment with a length equal to the projectile's radius. The drag coefficients of the rigid projectiles were found to be constant up to velocity which is equal to half the sound velocity in water, and they increase for higher projectile velocities. The drag coefficients for projectiles penetrating fluid aluminum targets were found to be the same as those for projectiles penetrating water targets. We also highlight the difference between drag coefficients of conical and ogive nosed projectiles having the same sharpness and offer a possible account for this difference.