Simulation of Two-dimensional Rigid Elliptic Head Structure Water Entry at High Speed

When a two-dimensional rigid elliptic head structure enters water at high speed, it endures tremendous impact arising from free water surface. It is very difficult to calculate the impact load by using normal dynamic method because of the nonlinearity of fluid-structure interface and the severe fluctuation of free water surface in the process of water entry. This paper simulates water entry of a structure with elliptic head by using the arbitrary Lagrangian-Eulerian(ALE) algorithm of ANSYS/LS-DYNA software. Simulation results show that the peaks in pressure curves increase with velocity of water entry, and there is a exponential relation between maximum acceleration and water entry velocity as this structure enters water at a specific angle. The maximum pressure appears when the angle is 35.