Study on Ballistic Characteristics of the Parallel Supercavitating Projectiles

To investigate the effects of the spacing of parallel projectiles on the hydrodynamic properties and ballistic characteristics of the projectiles, a water-entry simulation model of projectiles is established on the bases of the volume of fluid(VOF) multiphase flow model, the multi-reference system, the dynamic grid and the mobile computing domain technology. The water-entry free-deceleration processes of single projectile and parallel projectiles are simulated for different spacing of the projectiles, respectively. The results show that: 1) in parallel launching condition, the projectile is subjected to lateral force, when there is an angle of attack, the cavity has obvious offset and is easier to be punctured by the projectile, and the smaller the parallel spacing, the longer the puncturing distance; 2) the drag coefficient of the parallel projectiles is significantly higher than that of the single projectile, and when the parallel spacing is 75 mm, the drag coef-ficient increases by 34.92%; and 3) the stability of the parallel projectiles is affected by the parallel spacing, and in the case that the parallel spacing is 50 mm, the parallel projectiles overturn with instable trajectories, but this effect gradually weakens as the parallel spacing increases, and the trajectories of the parallel projectiles become stable when the parallel spacing is 100 mm. This research may provide reference for engineering application of parallel supercavitating projectiles.