潜射导弹出水载荷数值算法研究

SIMULATION OF UNDER-WATER LAUNCHED MISSILE’S WATER-EXIT LOAD

潜射导弹在水中航行时,表面被空泡包围,这就造成其出水时,带来较大的载荷冲击.出水冲击载荷需要知道整个表面上的压力分布,但是这在工程实践中是不可能实现的.本文采用有限元流固耦合仿真程序,对潜射导弹整个出水过程进行数值模拟.根据数值计算结果,依据理论力学的基本原理,计算出潜射导弹所受到的冲击力与冲击力矩,利用NASTRAN瞬态载荷解算器,计算出潜射导弹各截面最大响应弯矩.结果表明,本文提出的方法能够对潜射导弹出水过程提供数值预测与安全评估.

The high-speed missile in water is wrapped by cavitations, which implies a heavy water-exit load. It is essential to obtain the pressure distribution as whole in order to compute the load. However, it is not possible in reality. In this paper, the water-exit process is simulated by the FEM （finite element method） liquid- solid coupling method. Based on some fundamentals of the theoretical mechanics, the impact and the impact moment are computed. Using NASTRAN, the maximum corresponding bending moments in all cross-sections are obtained. The results show that the computation in this paper can predict and assess the water-exit process of the vehicle.