Examining the Influence of the Water Entry Velocity of Projectiles on Supercavity Flow and Ballistic Characteristics under Wave Conditions

Abstract

In this study, we aim to examine the influence of water entry velocity of a single and two tandem projectile(s) on the supercavitation flow and projectile loading under wave conditions using numerical simulation. The volume of fluid model, renormalization group (RNG) κ-ε turbulence model, and Schnerr–Sauer cavitation model are adopted to simulate the multiphase, turbulent, and cavitation flow, respectively. The projectile movement is considered using overlapping grids and a six-degree-of-freedom model. The results show that as the projectile velocity increases, both the dimensionless maximum radius and length of the cavity, as well as the yaw angle, also increase with the rising water entry velocity. For the two tandem projectiles, the cavity pattern on the second projectile varies as the projectile velocity changes. With a lower projectile velocity, the second projectile cannot directly access the front cavity, and there may be situations wherein the part of the second projectile is not enveloped by cavity. As the projectile velocity increases, the second one can directly enter the cavity of the first projectile without forming a separate cavity around itself. In all of the examined cases, the peak pressure on the first projectile is approximately an order of magnitude higher than that on the second one. Furthermore, with increasing projectile velocity, the pressure peak ratio between the first and second projectiles increases.

Keywords

• supercavitation
• wave model
• fluid dynamics
• multiple projectiles
• yaw angle