Numerical Study of the Wake Separation and Reattachment Effect on the Trajectory of a Hard Projectile

Abstract

The projectile may detach from the target during penetration, while the reattachment may or may not occur after the separation. This phenomenon is termed as the wake separation and reattachment. Firstly, a general framework of rigid projectile penetration with both the free-surface and the wake separation and reattachment effects is presented and implemented into ABAQUS. This methodology eliminates the need for discretizing the target as well as the need for a complex contact algorithm. Secondly, the framework is verified by comparison between the experimental data and simulation results in terms of depth of penetration, residual velocity and projectile trajectory. It is found that the influence of the wake separation and reattachment on the trajectory of a hard projectile is obvious. Furthermore, the location of the centroid, length-diameter ratio of the projectile and attack angle have a great effect on the trajectory stability. The projectile trajectory becomes more instable with the increase of Lc/ L and decrease of L/ D. A small attack angle can cause large direction change of the trajectory, making the trajectory greatly instable.