Water entry of vertical cylindrical shell is a nonlinear and unsteady process that involves the coupling of multiphase flow. In this paper, a numerical simulation of the water entry of vertical cylindrical shell is carried out with an objective to examine the physical mechanism of flow characteristics due to the effect of inner diameter. The numerical results are validated and verified against the experimental data. From the flow characteristics, the phenomena of cavitation closure can be identified as the cavity evolution the deep closure, the semi-closed mode and the non-cavity closure. The effect of inner diameter of cylindrical shell shows to have a significant influence on the cavity closure mode and time, and its geometry profile. The parametric study showed that the acceleration of cylindrical shell decreases with increasing inner diameter in the process of water entry. The formation of pressure, velocity and multi-scale vortices indicate the complex distribution of these components changing with space and time.

垂直圆柱壳的入水是一个非线性且不稳定的过程，涉及多相流的耦合。本文对立式圆柱壳的进水进行了数值模拟，目的是研究由于内径的影响而引起的流动特性的物理机理。数值结果经过实验数据验证和验证。从流动特性来看，空化闭合现象可以被识别为腔体演化为深层闭合，半闭合模式和非孔腔闭合。圆柱壳内径的影响显示出对型腔闭合方式和时间及其几何形状的显着影响。参数研究表明，在进水过程中，圆柱壳的加速度随着内径的增加而减小。压力，速度和多尺度涡的形成表明这些成分的复杂分布随空间和时间而变化。