3D multi-resolution SPH modeling of the water entry dynamics of free-fall lifeboats

Lifeboats can be launched through free-fall in extreme maritime accidents to fast leave the hazardous area, which deserves particular attention because it is tightly related to the safety of lifeboats and the carried passengers as well. This paper, within the framework of a fully 3D and multi-resolution Smoothed Particle Hydrodynamics (SPH) model, aims at investigating the water entry dynamics of a free-fall lifeboat with different water entry angles. First of all, two rigorous model validations are performed to demonstrate the accuracy, stability and convergence of the present SPH model. Furthermore, the water entry dynamics of the lifeboat with respect to different water entry angles, including the motion characteristics and cavity evolutions, is investigated and discussed in detail based on the SPH results. It is clearly demonstrated that the present SPH model possesses (1) satisfactory accuracy for predicting the water entry dynamics of a lifeboat, and (2) a better ability to capture the splashing jets and scattering droplets than mesh-based solvers thanks to its entirely Lagrangian nature. In addition, it is also demonstrated that the water entry angle exerts significant effects on the water entry dynamics of a lifeboat, which should be taken into account in the design stage to provide safer productions.

Automated summary

This study investigates the water entry dynamics of a free-fall lifeboat with different water entry angles using a 3D and multi-resolution Smoothed Particle Hydrodynamics (SPH) model. The results show that the SPH model has satisfactory accuracy in predicting the water entry dynamics of a lifeboat and can better capture splashing jets and scattering droplets compared to mesh-based solvers. The study also highlights the significant effects of the water entry angle on the water entry dynamics of a lifeboat, emphasizing the importance of considering this factor in the design stage.