Numerical investigation on supercavitation hydrodynamics of high-speed water entry projectiles under effect of different head shapes

The high-speed water entry dynamics and hydrodynamics of the projectiles are significantly influenced by the head shape and initial velocity. In this study, we numerically investigated unsteady cavitation dynamics during the water entry process and the hydrodynamic characteristics in the initial stages of conical, hemispherical, and blunt projectiles. We covered Froude numbers between 289 and 515, which are commonly handled in various industries. A preconditioned three-phase Navier-Stokes solver based on a homogeneous flow assumption was used for the numerical simulations. A dual-time stepping algorithm was applied to the current solver for physical time accuracy. The supercavitation regime under high-speed entry conditions with three projectiles is discussed, and the influence of the head shape on the pressure distribution, velocity, drag coefficient, and projectile shape is discussed in detail. Consequently, we suggest the physics of a high-speed water entry projectile based on the flow fields, cavitation dynamics, and time-dependent hydrodynamics under the effects of the projectile head shapes and initial velocity.