Influence of angle of attack on the semi-sealed cylindrical shell during high-speed water entry

The fluid–structure interaction based on STAR-CCM+ and ABAQUS collaborative simulation is adopted in this paper, which is combined with the overset mesh technology, and the cavity evolution and motion characteristics of the semi-sealed cylindrical shell with the angle of attack during high-speed water entry are studied. The results show that the shell with an angle of attack experiences significant deflection after penetrating into the water, which is due to the fluid hitting the upper wall of the shell and generating a large torque. The deformation of the horizontally placed shell is much more obvious than that of a vertically placed shell during water entry. Due to the deformation of the shell, the direction of the fluid's force can be changed, resulting in a horizontal component force, causing a horizontal movement of the horizontal shell during water entry. As the angle of attack decreases, the volume of fluid entering into the shell gradually decreases, resulting in a decrease in the volume of fluid flowing out of the shell. The shell with an angle of attack less than 75° causes the top wall to come into contact with the water surface during the deflection process, which also generates new cavities below.