The Analysis Of Water-exit Attitude And The Load Characteristic Of Submarine-based Missiles

The paper mainly studies water-exiting load of the submarine-based missile and the changes of attitude. The mechanical environment is very complex, when the submarine-based missile is out of water. The missile under water is effected by the load of fluid most, and the load of submarine environment plays the most important affect, when the missile is near to the free face of fluid. In the moment of water-exiting, the hydraulic pressure and flotage disappear, so the beating of wave will have a great impact to the changes of attitude.In the first part, the paper introduces the history and the current status of research on the water exit of the structure at high speed at home and broad, which draws the significance of the research on the launch of the missile at high speed. Meanwhile the paper uses a lot of literature referred to the concept of fluid-solid interaction and its classification. Particularly the paper focuses on the ALE algorithm of numerical methods and establishes a certain under-water mathematics model of a guided missile. Secondly, application ANSYS/LS-DYNA numerical method establishes the water-exit model and LS-DYNA is applied to analyze to the model. The model includes three parts. One is water modeled with Euler grid, and air also is modeled with Euler gird, the last one is the structure of missile which is modeled with Lagrangian grid. In the paper, typical spherical structure is used. The problems of missile out of water in different velocity and different depth are analysed in detail. We get the changes of the pressure and stress and some of dynamics changes. Meanwhile the changes of the flow field in the process of missile out of water are given. In the last, application the theory of binary rules wave establishes the mathematics model of wave. The paper draws some conclusions explaining the effect on the missile water-exit gesture by the different speed and different wave load. The results of simulation show that the effect of wave can not be neglected near the surface of water. The orientation angle and the initial phase of wave have a great impact too.The process of missile water-exit is complex, the conclusions of simulation in this paper can be referred to the missile designing, parameters choosing and security evaluating.