Numerical Investigation on Water Entry Behaviors of Free-Fall Lifeboat Under Different Launch Conditions

The safe water entry of free-fall lifeboats is critically important, particularly in emergency situations where passenger safety must be ensured. Although there have been relevant studies, there remains a lack of comprehensive analysis on the behavior of lifeboats entering regular waves. To address this issue, this study systematically investigates the water entry process of lifeboats using the arbitrary Lagrangian-Eulerian (ALE) method. Initially, the water entry of a cone is simulated and compares with experimental results to validate the effectiveness and accuracy of the ALE model. Subsequently, the ALE model is used to simulate the entry of a free-fall lifeboat into calm water, and the results are compared with those obtained from simulations using the Smoothed Particle Hydrodynamics (SPH) method in other literature. The study then examines the impact of various entry angles on the lifeboat's water entry process. Additionally, two different descent velocities are selected to simulate the lifeboat's entry into both calm water and regular waves, and a comparative analysis of the results is conducted.