The realistic three-phase water entry of a free-fall cylinder is investigated in this paper using an efficient lattice Boltzmann method (LBM) with automatic interface capturing capability implemented in an in-house FORTRAN 90 code. The numerical method takes advantage of automatic interface capturing, using a real equation of state (EOS), and considering the surface tension and gas phase compared to the free-surface LBM used for water entry simulations in a few previous LBM works. Simulation results are first compared with other numerical and experimental data with good agreements. Variation of the cylinder trajectory and cavity diameter is presented, and effects of the Froude number, solid density, and surface wettability are investigated. Data analysis shows that the non-dimensional cavity diameter vs. non-dimensional time is independent of the Fr number, or impact velocity, and obeys a power-law trend almost the same as the one reported for variation of the non-dimensional crown diameter for the droplet impact on a liquid film or a deep liquid. The penetration depth during time is almost linearly increased with the impact velocity and solid density. As the surface wettability increases, the penetration depth is reduced, and the deviation of different wettability curves increases with time.

本文使用高效的格子玻尔兹曼方法 (LBM) 研究了自由落体圆柱体的真实三相水进入，该方法具有在内部 FORTRAN 90 代码中实现的自动界面捕获功能。数值方法利用自动界面捕获，使用实数状态方程 (EOS)，并考虑与之前一些 LBM 工作中用于水进入模拟的自由表面 LBM 相比的表面张力和气相。首先将模拟结果与具有良好一致性的其他数值和实验数据进行比较。介绍了圆柱体轨迹和腔体直径的变化，并研究了弗劳德数、固体密度和表面润湿性的影响。数据分析表明，无量纲腔直径与 无量纲时间与 Fr 数或撞击速度无关，并且服从幂律趋势，几乎与报道的液滴撞击液膜或深层液体的无量纲冠径变化相同. 随着时间的推移，穿透深度几乎随冲击速度和固体密度线性增加。随着表面润湿性的增加，渗透深度减小，不同润湿性曲线的偏差随时间增加。