Analysis of influencing factors of the projectile entering the water through the ice hole

Abstract

The ice hole, as a special constraint environment, affects the dynamics of water entry. In this paper, the finite volume method (FVM) is used to study the cavity dynamics of the projectile passing through the ice hole. The results show that the cavity evolution law of the projectile passing through the ice hole is different from that of the projectile entering the water freely, and the backflow of the splash crown occurs near the hole. As the Froude number (Fr) increases, the time when the splash crown flows back at the hole is earlier, and the time when the cavity pinch-off occurs at the tail of the projectile is also earlier. The fluctuation of force decreases, and the velocity variation becomes more stable as the Fr decreases. After the projectile with a large aspect ratio passes through the ice hole, the cavity collapse becomes more obvious, and the resistance increase. The constraint effect of the hole on the cavity strengthens as the hole thickness increases, and the cavity integrity after the pinch-off becomes worse. After the projectile passes through the hole, the resistance and force fluctuation increase as the hole thickness increases.