Experiment And Numerical Study On Vertical And Oblique Water Entry Of Revolution Body

The application range of water entry covers high-tech fields in aerospace,ships and underwater weapons,such as the recovery of spacecraft capsules,the navigation of high-speedboats,submarine weapons water exit and antisubmarine weapons water entry and the development of underwater rifle weapons,etc.and diving,etc.in daily civilian production and life The water entry motion has a significant impact on the structure,such as high-speed motion and cavitation effects.The current limited progress and the significance of the water entry motion push it to extensive exploration and research value in various fields.The experiment is conducted to study the motion and cavitation of projectiles at high-speed oblique water entry.The different types of projectiles are used for multiple experiments,and high-speed cameras are used to capture the high-speed movement of projectiles and the characteristics of cavitation.Firstly,the geometry of the projectile and experimental setup are introduced,and the high-speed oblique water entry experiment is analyzed statistically.The motion and trajectory changes of the revolution body when entering the water at high speed vertically and obliquely are studied.Then,when the projectile trajectory is stable,the evolution of the natural supercavity is analyzed.Experiments have revealed the re-expansion process of natural supercavitation.The commercial software STAR-CCM+was used to simulate the vertical motion of the revolution body.Based on the computational fluid dynamics method,the overlapping mesh and 6-DOF method were used to simulate the water entry process,and the coupled motion was analyzed using the appropriate mesh size and time step scheme to verify the computational effectiveness.Through the combination of experiments and CFD,the water entry of the revolution body was studied.The commercial software STAR-CCM+was used to simulate the oblique motion of the revolution body.The trajectory deflection and the parameters of the revolution body will have an impact on the trajectory stability and impact loads during the water entry process.The parameters of the projectile,the initial speed and angle,and the projectile deflection angle are used to study the trajectory and impact.The comparison of the numerical supercavity profiles?the projectile resistance and resistance coefficient under different conditions are obtained.We also monitor the subsequent flow field and the projectile head pressure changes under different water entry periods.The motion of the projectile with deflection between the speed direction and the axial direction is calculated during the process of water entry.