Multi-phase flows are common and significant for ship and ocean engineering^[1]. The water entry problem involves violent multi-phase flows and deforming interfaces, where the discontinuity across the interface between different phases with large density ratios usually leads to numerical instability and thus poses great challenges for numerical simulations. Smoothed particle hydrodynamics (SPH) method is a meshless and Lagrangian particle method^[2], which is easy to deal with free surfaces and large deformation problems. Multi-phase interfaces can be naturally captured without interface tracking technology by SPH. Therefore, SPH method has unique advantages in solving multi-phase flows. In this paper, we develop an SPH method for multi-phase water entry based on a weakly-compressible SPH model for multi-phase flows with large density ratios while allowing large CFL numbers^[3]. With the GPU-accelerated SPH method, the 2D & 3D water entry is numerically investigated with some analysis and interesting findings of kinematic and dynamic characteristics^[4].

Keywords: Smoothed particle hydrodynamics; Multi-phase flows; Water Entry;

GPU acceleration.

References

[1]    Yang Q, Xu F, Yang Y, et al. A GPU-accelerated adaptive particle refinement for multi-phase flow and fluid-structure coupling SPH[J]. Ocean Engineering, 2023, 279: 114514.

[2]    Liu, M. B., & Liu, G. (2010) Smoothed particle hydrodynamics (SPH): an overview and recent developments, Archives of Computational Methods in Engineering, 17(1), 25-76.

[3]    He F, Zhang H, Huang C, et al. A stable SPH model with large CFL numbers for multi-phase flows with large density ratios[J]. Journal of Computational Physics, 2022, 453: 110944.

[4]    Zhang H, Zhang Z, He F, et al. Numerical investigation on the water entry of a 3D circular cylinder based on a GPU-accelerated SPH method[J]. European Journal of Mechanics-B/Fluids, 2022, 94: 1-16.