Investigation of the Influence of Propeller Rotational Speed on the Flooding Process, Navigational Trajectory, and MotionResponse of a Damaged Naval Ship

To investigate the influence of propeller rotational speed on the flooding process, sailing trajectory, and motion responses of a damaged surface naval ship under various sea conditions, numerical simulations were conducted using STAR-CCM+. The study is based on the Finite Volume Method (FVM), the Volume of Fluid (VOF) approach, the body force method, overset grids, and a multi-degree-of-freedom motion system. The flooding behavior, trajectory evolution, and hydrodynamic responses of the damaged naval ship were analyzed under calm water, head sea, and beam sea conditions, each at four distinct propeller speeds. The research findings indicate that, regardless of the sea state, a damaged naval ship initially travels in a straight line for a certain distance before transitioning into a curved trajectory. The length of the straight-line travel remains largely unaffected by variations in propeller rotational speed but varies with different sea conditions. Notably, under beam sea conditions, this distance exhibits a significant reduction. The subsequent curved motion trajectory is significantly influenced by the propeller rotational speed and varying wave directions. In calm water, the motion exhibits repetitive circular trajectories toward the damaged side, with the diameter of the circular path increasing as the propeller speed rises. Under head and beam sea conditions, the vessel exhibits a helical motion, with the trajectory becoming more pronounced as the propeller rotational speed increases. In all three wave conditions, the maximum cumulative ingress of the damaged compartment is positively correlated with the propeller speed, whereas the ship’s roll, pitch, and heave motions exhibit distinct variation trends.