Asymmetric flow action on hydrodynamics and structural dynamics for high-speed oblique water entry of the semi-sealed cylindrical shell

Abstract

To study the hydrodynamics and structural characteristics, numerical simulation of the oblique water-entry process of the semi-sealed and completely sealed cylindrical shell is carried out based on a Star-CCM+ and ABAQUS collaborative simulation method described in this paper. The results show that when the internal fluid pours out of the shell, the jet formed below the shell is asymmetrically distributed, resulting in a significant change in the attitude angle of the shell. This, in turn, causes the upstream surface of the shell to hit the side wall of the cavity, further changing in the attitude angle. The force and stress of the shell with an water entry angle θ0 = 90° is found to be greater than that of the shells with other oblique water entry angles. Additionally, the trajectories of the shells at different water entry angles move upward after reaching the inflection point, and the range of upward movement increases gradually with the decrease of the water entry angle. In summary, the asymmetric flow caused by an hollow structure has a profound impact on the high-speed oblique water entry of the semi-sealed cylindrical shell, causing changes in its trajectory, cavity evolution, and structural characteristics.