Abstract:The initial disturbance of water-entry has an important influence on the stability and structural deformation of the projectile with high-speed. The initial disturbance includes both the angle of attack and the side-slip angle , but the current research on the initial disturbance mainly focuses on the change of the angle of attack. In order to obtain the fluid-structure interaction characteristics during the oblique water-entry of the projectile by the side-slip angle, a fluid-structure interaction numerical method based on the computational fluid dynamics and computational structural dynamics model is adopted to study the supercavity evolution, dynamics and structural response characteristics of the projectile under the side-slip angles are 0°,1°,2°,3°,4°,5°, when the water-entry velocity v=700m/s and the water-entry angle is 3°. It is found that: (1) During the high-speed oblique water-entry process, the side-slip angle affects the trajectory of the projectile. When the side-slip angle is less than the critical value, with the increase of the side-slip angle, the trajectory is straight, and the shape of the supercavity is regular, but the yaw motion of the projectile is strengthened; when the side-slip angle is bigger than the critical value, the trajectory will be curved due to the bending deformation of the projectile and the head-up motion out of the water, and the supercavity will also be bending. (2) The deformation of the projectile during water-entry is mainly dominated by bending deformation, and the value of tensile plastic strain is slightly larger than that of compressive deformation. And the plastic strain is not continuous growth, there is a stage of growth characteristics, the larger the growth rate, the shorter the maintenance time of the stable section.
