Kinematic response analysis of a three-dimensional lifeboat water entry based on smoothed particle hydrodynamics

The water entry process is a typical fluid-structure interaction. During this process, predicting the impact load and summarizing the evolution law of the free surface have important reference significance for the design of ship structures. To solve this problem, the model based on smoothed particle hydrodynamics (SPH) was used for numerical simulation. This manuscript introduces the six degrees of freedom motion equation of rigid body and GPU acceleration technology to establish a 3D SPH high-performance numerical model. The accuracy of the improved SPH numerical model was verified by simulating the boat water entry experiment. On this basis, considering the problem of the lifeboat slamming into the water at an angle, a 3D real-scale numerical model of the lifeboat and the water area was established, and the effects of the angle of entry and different initial velocities on the lifeboat were studied. A fitting function for the pitch angle of the lifeboat was proposed. Finally, summarize the three motion patterns of lifeboat water entry and analyze their advantages and disadvantages, providing a reference for ship structure design and maritime rescue.